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HomeMy WebLinkAboutRes 1807 - DOCUMENT: 2013 Surface Water Comprehensive Plan (Repealed by Res 2098)Following is 2013 Surface Water Comprehensive Plan Adopted by Res 1807 CITY OF TUKWILA 2013 SURFACE WATER COMPREHENSIVE PLAN Tukwila41 FF. Prepared by CH2MHILL. February 2013 Final City of Tukwila 2013 Surface Water Comprehensive Plan Prepared for Tukwila, WA February 2013 Prepared by CH2MHIL. Contents Acronyms and Abbreviations iii 1.0 Introduction 1 -1 1.1 Background 1 -1 1.2 Plan Objective 1 -1 1.3 Report Organization 1 -1 2.0 Drainage Basin and Watershed Characteristics 2 -1 2.1 General Description 2 -1 2.2 Drainage Basins 2 -1 2.3 Population, Existing Land Use and Future Development 2 -4 2.4 Drainage System Characterization 2 -7 2.5 Water Quality Characterization 2 -10 2.6 Aquatic Habitat Characterization 2 -12 2.6.1 Green /Duwamish River 2 -12 2.6.2 Gilliam Creek 2 -12 2.6.3 Riverton Creek 2 -13 2.6.4 Southgate Creek 2 -13 2.6.5 Johnson Creek 2 -14 2.6.6 Mill Creek 2 -14 3.0 Regulations and City Policies 3 -1 3.1 Applicable Surface Water Regulations 3 -1 3.2 Potential Regulatory Changes 3 -1 4.0 Surface Water Issues and Solutions 4 -1 4.1 Available Data and Information 4 -1 4.2 Identified Surface Water Issues 4 -1 4.3 Menu of Solutions to Address Surface Water Issues 4 -4 4.3.1 Programmatic Solutions 4 -4 4.3.1.1 Education 4 -5 4.3.1.2 Incentives 4 -6 4.3.1.3 Regulatory and Policy Changes 4 -6 4.3.1.4 Inspection and Enforcement 4 -6 4.3.1.5 Illicit Discharge Detection and Elimination 4 -7 4.3.1.6 Public Involvement 4 -7 4.3.1.7 Surface Water System Maintenance 4 -7 4.3.2 Capital Project Solutions 4 -8 4.3.2.1 Drainage 4 -9 4.3.2.2 Water Quality 4 -10 4.3.2.3 Aquatic Habitat 4 -11 4.4 Solutions to Tukwila's Surface Water Issues 4 -11 5.0 Capital Improvement Projects 5 -1 WBG031611103411 SEA\TU KW I LASURFACEWATERCOMPPLAN _FINAL_V2. DOCX CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN 5.1 412 Fund (Drainage and Water Quality) 5 -1 5.2 301 Fund (Fish Habitat) 5 -3 6.0 Operations and Maintenance 6 -1 6.1 Surface Water Maintenance Activities 6 -1 6.2 Regulatory Compliance 6 -1 6.3 Surface Water Maintenance Policies 6 -1 7.0 Recommendations 7 -1 7.1 Recommended Activities 7 -1 7.1.1 Capital Projects 7 -1 7.1.2 Programmatic Solutions and Policies 7 -1 7.1.2.1 Education 7 -1 7.1.2.2 Incentives 7 -1 7.1.2.3 Regulatory and Policy Changes 7 -1 7.1.2.4 Inspection and Enforcement 7 -2 7.1.2.5 Public Involvement 7 -2 7.1.2.6 Surface Water System Maintenance 7 -3 7.1.2.7 Habitat Manager 7 -3 7.2 Schedule for Implementation 7 -3 8.0 References 8 -1 Tables 1 Drainage Basin Areas Summary 2 -4 2 Tukwila Land Use Zoning and Undeveloped Land 2 -6 3 Surface Water Pump Stations 2 -10 4 Surface Water Issue Summary 4 -2 5 Surface Water Issue Types Addressed by Programmatic Solutions 4 -5 6 Surface Water Issue Types Addressed by Capital Projects 4 -8 7 Surface Water Issues and Solutions 4 -13 8 Drainage and Water Quality Capital Projects - 412 Fund 5 -1 9 Fish Habitat Capital Projects - 301 Fund 5 -3 Figures 1 Vicinity Map 2 Drainage Basins 3 Zoning 4 Infiltration Not Allowed 5 Level 2 Stormwater Detention 6 Surface Water Issues 7 Capital Improvement Projects Appendices A Map Book B Drainage, Water Quality, and Fish Habitat Characterization C Surface Water Regulations and Policies D Surface Water Issues and Solutions E Surface Water Capital Projects WBG031611103411 SEA 1TUKWILASURFACEWATERCOMPPLAN _FINAL_V2.DOCX Acronyms and Abbreviations CBD Southeast Central Business District EPA U.S. Environmental Protection Agency ESA Endangered Species Act GIS Geographic Information System LF linear feet LID Low Impact Development mg/L milligrams per liter NPDES National Pollutant Discharge Elimination System ROW right -of -way SEPA State Environmental Policy Act TMDL total maximum daily load TSS total suspended solids TUC Tukwila Urban Center WDFW Washington Department of Fish and Wildlife WSDOT State of Washington Department of Transportation WBG031611103411 SEA\TU KW I LASURFACEWATERCOMPPLAN _FINAL_V2. DOCX 1.0 Introduction 1.1 Background The purpose of this Comprehensive Surface Water Management Plan is to provide a strategic framework for the management of surface water within the City of Tukwila. This Surface Water Plan is intended to be a flexible document that may be revised should priorities or regulatory requirements change. This Surface Water Plan can also serve as a reference for City departments whose activities may impact surface water drainage, water quality, or aquatic habitat concerns. This 2013 Surface Water Plan is an update to the Surface Water Plan prepared in 2003 (CH2MHILL 2003). The previous surface water plan was prepared in 1993. This 2013 Surface Water Plan addresses changes that have taken place since 2003, including the annexation of 259 acres into the City of Tukwila in 2009, expansion of regulatory requirements, and changing surface water management techniques and strategies. This 2013 Plan also reflects the surface water capital and non - structural investments that the City of Tukwila has made since the 2003 Surface Water Plan, including addressing priority drainage, water quality, and aquatic habitat issues identified in that plan. 1.2 Plan Objective The objective of this 2013 Surface Water Plan is to provide a surface water management framework that will protect the public's health and safety, protect both public and private property, conserve and enhance the natural aquatic systems within the City, and maintain compliance with local, state, and federal regulations related to surface water. 1.3 Report Organization The main body of this Surface Water Plan consists of a series of sections that summarize the general topics of this plan. Technical conclusions as well as detailed information are included in the appendices. The Plan includes the following sections: • Section 1- Introduction • Section 2 - Drainage Basin and Watershed Characteristics (supporting information in Appendix A and in Appendix B) • Section 3 - Regulations and Policies (supporting information in Appendix C) • Section 4 - Surface Water Issues (supporting information in Appendix D) • Section 5 - Capital Improvement Projects (supporting information in Appendix E) • Section 6 - Operations and Maintenance • Section 7 - Recommendations WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 1 -1 2.0 Drainage Basin and Watershed Characteristics This section contains a description of the physical characteristics of the City of Tukwila. Drainage, water quality, and aquatic habitat conditions are also presented. Appendix B contains the detailed information in support of this Section 2. 2.1 General Description The City of Tukwila encompasses approximately 9.7 square miles straddling the Green and Duwamish Rivers (Figure 1). The climate is strongly influenced by the Pacific Ocean with wet and mild winters with temperatures varying from 30 °F to 50 °F and dry and cool summers with temperatures typically less than 80 °F. The average annual precipitation is between 32 and 38 inches. The Green and Duwamish Rivers and associated floodplains dominate the geography and topography of Tukwila. Relatively flat and poorly drained floodplains exist adjacent to the rivers and steep valley walls dominate the areas on the west side of Tukwila along the I -5 corridor. Soils in the valley floor tend to be fine sandy loam and silty clay loam (Newberg and Woodinville Series, respectively). The valley walls typically are comprised of soils from the Alderwood Series (interbedded silts and clays) and are characterized by numerous hillside springs and the accompanying potential for instability. 2.2 Drainage Basins The City has been divided into nine drainage basins (Figure 2): • Green / Duwamish River Mainstem • Gilliam Creek • Nelson Place - Long Acres • P17 • Riverton Creek • Southeast Central Business District (CBD) • Southgate Creek • Johnson Creek • Mill Creek Portions of these basins are located outside City limits as shown in Table 1. The basin boundary delineation was based on information from field visits, the City Geographic Information System (GIS), and previously developed basin plans. The City of Tukwila has finished an inventory and mapping of the drainage network. Basin boundaries should be periodically re- visited to ensure the inventory is up to date. Appendix A to this Plan includes a Surface Water map book, a summary of this inventory and mapping to date. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2 -1 King County International Airpor ._.._.._.� King County • • • • • • Burien Black River • • • • • • • • Seattle- Tacoma International Airport SeaTac Normandy Park r.. • Des Moines 'V Ki ng(Cou my City of Tukwila 1 King County Unincorporated : Other Municipalities Streams and Rivers 0 1 2 3 N Miles FIGURE 1 City of Tukwila Vicinity Map City of Tukwila 2012 Surface Water Comprehensive Plan SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \FIGUREI VICINITYMAP.MXD TJANTZEN 10/17/2011 07:40:32 CH2MHILL Seattle •_.• ••••• •••■• •1 ".4Mercer 4 1 4.4 • • • • King County \Green /Duwamish Lake Washington 4 Y Y "Le-■•■•■■••• King County y se Black River 19 \° G1 t- Renton Li elson d Springbrook unty PS Normandy Park 4 � . s • • S 1 t St . v Mill Creek • Moines Puget Sound Kent Drainage Basins • Tukwila Stormwater Pump Station I`• _� King County Unincorporated • Pump Station Owned by Others Other Municipalities City of Tukwila N 0 1 2 Miles FIGURE 2 City of Tukwila Drainage Basins City of Tukwila 2012 Surface Water Comprehensive Plan SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\FIGURE2 DRAINAGEBASINS.MXD TJANTZEN 4/2/2013 09:39:38 CH2MHILL CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE 1 Drainage Basin Areas Summary Basin Name Area of Basin in Percent of Total Basin City of Tukwila Basin in City of Area (acres) (acres) Tukwila Green /Duwamish River Mainstem 4,250 2,613 61% Gilliam Creek 1,774 1,314 74% Nelson Place / Long Acres 93 94 101% P17 1,348 777 58% Riverton Creek 452 393 87% Springbrook Creek 23 23 100% Southgate Creek 546 484 89% Johnson Creek 1,833 309 17% Mill Creek 87 87 100% Total 10,406 6,094 2.3 Population, Existing Land Use and Future Development The City of Tukwila's population is approximately 19,000 residents with an estimated 42,000 people employed at businesses located within the City of Tukwila. The resident population of Tukwila is not expected to change dramatically over the 7 -year planning period covered by this Plan. Any increase in residents would be due to redevelopment that may increase residential densities. The number of those employed within the City of Tukwila may increase with additional commercial development throughout the city, most notably the Tukwila South project described later in this section. The 2030 targets for additional residents and employees are 4,800 and 15,000, respectively. Land use within the City of Tukwila varies from undeveloped natural land to highly developed industrial areas. The City is almost fully developed with those undeveloped acres in sensitive areas and in locations that are difficult to build such as steep slopes. Figure 3 shows the zoning within the City of Tukwila and Table 2 lists the distribution of land uses by drainage basin. The City of Tukwila annexed 259 acres on the south end of the city on December 31, 2009, referred to as the Tukwila South Annexation. In the future, the boundaries of the City of Tukwila may change due to boundary adjustments or additional annexations. Other possible annexations include areas to the north of the city limits though no plan has been formalized. The Tukwila South development consists of 512 acres of land with boundaries of approximately S 180th Street to the north, the Green River to the east, S 204th Street to the south, and Orillia Road /I -5 to the west. This development includes the 259 acres annexed to the City of Tukwila as part of the Tukwila South Annexation. Stormwater management 2 -4 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX Seattle • • • • • • • King County i -L- {- -- •— w�r._J • Green/®uwa m ish • • Borien • • • • • • • • 1" • ° -• 1 • • • • • • • • • • • • • Drmandy Park ° ° • a Johnson' 1 1• t. f• ammo •'. -••••� • Mercer Islanc. ,• • A � •I h • King County �ba lac Nelson tt: Renton - ,Springbrook >eaTac 80th 'Mt-Greek • 11- -- ■ • f • i Des Moines • • • • Y • +Y Kent CLI, Commercial Light Industrial MIC /H, Manufacturing Industrial Center /Heavy - RCC, Residential Commercial Center HDR, High Density Residential - MIC /L, Manufacturing Industrial Center/Light MUO, Mixed Use Office LDR, Low Density Residential - NCC, Neighborhood Commercial Center LI, Lignt Industrial 0, Office MDR, Medium Density Residential - RC, Regional Commercial N HI, Heavy Industrial Miles RCM, Regional Commercial Mixed Use TUC, Tukwila Urban Center TVS, Tukwila Valley South QDrainage Basins Park FIGURE 3 City of Tukwila Zoning City of Tukwila 2012 Surface Water Comprehensive Plan SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUTFIGURE3 ZONING.MXD TJANTZEN 4/2/2013 09:51:39 CH2MHILL CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE 2 Tukwila Land Use Zoning and Undeveloped Land Other State Right -of- Un -Zoned Undeveloped Existing and Residential' Commercial' Industrial' Way'' 4 Areas' Land Planned Parks % of % of % of % of % of % of % of Basin Name Acres Basin2 Acres Basin2 Acres Basin2 Acres Basin2 Acres Basin2 Acres Basin2 Acres Basin Green/ Duwamish River Mainstem 607 23% 129 5% 1209 46% 263 10% 406 16% 94 4% 116 4% Gilliam Creek 646 49% 286 22% 0 0% 236 18% 145 11% 31 2% 29 2% Nelson Place / Long Acres 0 0% 64 68% 15 16% 14 15% 0 0% 19 21% 0 0% P17 80 10% 506 65% 99 13% 23 3% 69 9% 60 8% 26 3% Riverton Creek 168 43% 16 4% 125 32% 39 10% 44 11% 34 9% 0 0% Springbrook Creek 0 0% 1 3% 22 96% 0 0% 0 2% 11 48% 0 0% Southgate Creek 297 61% 47 10% 34 7% 37 8% 69 14% 18 4% 18 4% Johnson Creek 31 10% 230 75% 0 0% 0 0% 47 15% 0 0% 0 0% Mill Creek 0 0% 0 0% 74 85% 4 4% 9 11% 0 0% 0 0% Total 1829 30% 1280 21% 1578 26% 612 10% 782 13% 267 4% 189 3% 1 These five categories (Residential, Commercial, Industrial, State Right -of -Way [ROW], and Other Un -zoned areas) add up to 100% of the basin; Undeveloped Land totals and Parks totals are shown as stand -alone totals in table and also included in residential, commercial, and industrial totals 2 All percentages are of the portion of the basin within Tukwila City Limits 3 Nearly 100% of Johnson Creek was undeveloped in the 2009 aerial imagery, but much of the basin is slated for development in the near future. 4 State ROW boundaries used for this analysis are imprecise; these values are approximate. 2 -6 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2.0 DRAINAGE BASIN AND WATERSHED CHARACTERISTICS approaches and techniques are described in the developers' agreement with the City of Tukwila. One other redevelopment initiative is the Tukwila Urban Center (TUC). The TUC covers the area known as Southcenter. The TUC is bounded by I -5 to the west, I -405 to the north, the City limits to the east, and South 180th Street to the south. The TUC also includes the station at Long Acres that serves Amtrak and the Sounder commuter rail. The City issued a public review draft of the TUC Sub -Area Plan in February 2009. That Plan will serve as a guide to continuing growth and redevelopment of the TUC over the next 20 years, focusing on a transition from the current pattern of sub -urban development to an urban environment. The plan includes high- density, pedestrian oriented development served by high- capacity transit. Future development and re- development is undertaken in accordance with the City's storm drainage manual (at the time of this Report, 2009 King County Surface Water Design Manual). The City has identified areas where infiltration is not allowed as a surface water management approach due to steep slopes and /or high groundwater table (Figure 4). Flow control standards within the City of Tukwila depend on location within the City (Figure 5). In addition to the flow control standards within the 2009 King County Surface Water Design Manual, Tukwila has added two additional flow control standards referred to as 'Level 2 - Conservation to Existing Conditions' and as 'Basic - Peak Rate to Existing'. Table 5.1 in Chapter 5 of the City's Development Guidelines and Design and Construction Standards (City of Tukwila, 2010) includes descriptions of each of the flow control levels applicable within the City of Tukwila. The flow control standard that applies to most of the City, 'Level 2 - Conservation to Existing Conditions', means that runoff from the developed site will be controlled and released at a rate that matches the flow duration for the existing site conditions before the development (pre - project). The flow control duration standard requires runoff to be detained and released at a rate that matches the flow duration over the range of flows extending from 1/2 of the 2 -year up to the 50 -year flow and to also match developed peak discharge rates to existing (pre - project) peak discharge rates for the 2 -year and 10 -year return periods. Much of the City of Tukwila area east of 1 -5 falls under this category. The 'Basic - Peak Rate to Existing' flow control standard matches existing site conditions for areas that drain to constructed (man -made) drainage systems that drain directly to either a direct discharge exempt water body or to a receiving water body such that there is not a possibility of creating an erosion problem. The standard calls for matching the 2 -,10- and 100 -year peak runoff rate for existing conditions. This standard only applies to those portions of the Nelson Place /Long Acres Basin that drain to Springbrook Creek in the City of Renton. 2.4 Drainage System Characterization Supporting information for the drainage system, water quality, and aquatic habitat characterizations located in Sections 2.4, 2.5, and 2.6 of this Plan, respectively, and is contained in Appendix B. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2 -7 Seattle King 4111 4•=11 44 NEM 0 Normandy • • Burien PEd S 86th PI Boeing-4W • ii '� SR-595 County • . • • • • • • • • • S 1.2$th Riverton S1 3ydSt 35th Stf➢ ,Green /Duwam S 138th St //47/:, Y n,, 'A t� t' S S140f%S���8�� S Ithgate� S • h t g 4 rj Renton 405 164th S SeaTac Springbrook Saxon w S 188th St Mill Creek o I A Moine ata WV 4]0 • M4 Areas where infiltration not allowed =Drainage Basins N 0 1 2 Miles FIGURE 4 Infiltration Not Allowed City of Tukwila 2012 Surface Water Comprehensive Plan SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\FIGURE4 NOINFILTRATION.MXD TJANTZEN 4/2/2013 10:27:31 CH2MHILL Level 2- Conservation to Existing Level 2- Conservation to Forested Basic- Peak Rate to Existing Per Tukwila South Development Agreement N 0 1 V 2 Miles Drainage Basins FIGURE 5 Level 2 Stormwater Detention City of Tukwila 2012 Surface Water Comprehensive Plan SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \FIGURES STORMWATERDETENTION.MXD TJANTZEN 4/2/2013 11:34:14 CH2MHILL CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN All of the surface water in the City of Tukwila eventually discharges to the Green and Duwamish Rivers. The Green /Duwamish River meanders from the southeast to northwest through the City of Tukwila. The Green /Duwamish River is tidally influenced along most of length of the river within the City of Tukwila. The Green /Duwamish River is called the Duwamish below the confluence with the Black River and is called the Green River upstream of that point. Tukwila's drainage network consists of both closed -pipe and open channel conveyance. Numerous outfalls discharge to the Green and Duwamish Rivers with several tide gates preventing river and tidal flows from flowing up into the drainage basins. The outfalls with the largest discharge are typically associated with the creek systems located entirely or partially within the City, including Riverton Creek, Gilliam Creek, Southgate Creek, and Johnson Creek. Tukwila's drainage assets include pipes, manholes, ditches, ponds, culverts, and surface water pump stations. Table 3 lists each of the city -owned surface water pump stations (also shown in Figure 2). Outfalls, tide gates, pump stations, and other drainage assets are shown in the map book in Appendix A. Note that King County owns and operates a pump station (P17) within the City of Tukwila's P17 drainage basin. TABLE 3 Surface Water Pump Stations Station Name Physical Location Drainage Basin Ownership Sta #15 5880 S 180th Street — near Claim Jumper Restaurant P17 City of Tukwila Stormwater Utility Sta #16 7420 S. 180th Street — underpass Springbrook City of Tukwila Stormwater Creek, Green/ Utility Duwamish River Sta #17 Sta #18 Sta #19 530 Strander Boulevard — Bicentennial Green/ City of Tukwila Stormwater Park Duwamish River Utility 4225 S. 122nd Street — Allentown Fort Dent Park Green/ City of Tukwila Stormwater Duwamish River Utility Green/ City of Tukwila Parks Duwamish River Department It is possible that the City may acquire additional surface water assets after development of the south annexation area. The City should update this surface water asset inventory both in this comprehensive surface water plan and in the City's GIS when these surface water assets are put into service. 2.5 Water Quality Characterization Supporting information for the water quality characterization located in this Section 2.5 is contained in Appendix B. In 2003, Ecology adopted a water use -based classification for state surface waters (RCW 173 -201A, Table 602) that determines the surface water quality standards applicable 2 -10 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2.0 DRAINAGE BASIN AND WATERSHED CHARACTERISTICS for that water body (RCW 173 -201A- 600(1)). The Duwamish River (below the confluence with the Black River) is classified as Salmonid Rearing /Migration Only and Secondary Contact Recreation. The Green River (above the confluence with the Black River) is classified as Salmonid Spawning /Rearing Only and Primary Contact Recreation. None of the tributaries to these rivers within Tukwila is called out in Table 602. Therefore, the uses defined for tributaries are the same as the river to which they discharge. Riverton Creek and Southgate Creek discharge to the Duwamish River so they have a use -based classification of Salmonid Rearing /Migration and Secondary Contact Recreation. Gilliam Creek, Johnson Creek, and the Nelson Place / Long Acres, Southeast CBD, and P17 drainage basins have a use -based classification of Salmonid Rearing /Migration and Primary Contact Recreation. Ecology maintains a list of water bodies that do not meet water quality standards, known as the 303(d) list. The 2008 update is the current water quality assessment and 303(d) list for the state of Washington (at the time of preparation of this plan). Four sections of the Green /Duwamish River within the City of Tukwila do not meet water quality standards according to the 2008 303(d) list. Both the Green River and Duwamish River are listed as Category 5 (at least one designated use is impaired) for dissolved oxygen, temperature, pH, and fecal coliform, based on water sampling and analysis (Ecology 2010; Ecology 2006). Gilliam Creek is the only creek system in the City of Tukwila for which additional water quality data is available for this water quality characterization. Water quality sampling was performed during storm runoff events in the fall of 1999 as part of the Gilliam Creek Stormwater Management Plan (Herrera Environmental Consultants 2001). Temperature, dissolved oxygen and pH (the latter with the exception of one sample) all met current state water quality standards during this sampling. Turbidity was somewhat elevated, generally ranging from 25 to 50 NTUs. Similarly suspended solids were also only modestly elevated, generally ranging from 20 to 60 milligrams per liter (mg /L). Dissolved lead met applicable water quality criteria, as did nearly 90 percent of the dissolved zinc samples. About half of the samples failed to meet the dissolved copper criteria. Finally, nearly all of the fecal coliform samples exceeded the state water quality standards. In a study that had been conducted several years prior, two creek samples were collected during summer baseflow conditions (June and September of 1997). Several samples taken during these months did not meet the state dissolved oxygen standard, with one sample recorded at 3.2 mg /L, well below the state standard of 6 mg /L. These samples also fell slightly below the pH standard. In September the measured stream temperature of 17.5 degrees Celsius barely fell below the state standard of 18 degrees. The northern -most portion of the City of Tukwila lies within the Lower Duwamish Waterway Superfund Site, designated by the U.S. Environmental Protection Agency (EPA) in 2001. King County, the Port of Seattle, and the cities of Seattle and Tukwila are working with Ecology and the EPA to control sources of pollution in the Lower Duwamish Waterway. Ecology is the lead agency for implementing source controls in the Lower Duwamish Waterway. In 2002 the entities listed above formed the Lower Duwamish Waterway Source Control Work Group to coordinate source control activities. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2 -11 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN 2.6 Aquatic Habitat Characterization Supporting information for the aquatic habitat characterization located in this Section 2.6 is contained in Appendix B. A detailed fish - blocking culvert inventory is included in Attachment A to Appendix B. 2.6.1 Green /Duwamish River The Green /Duwamish River channel is significantly altered from its natural condition along most reaches in the City of Tukwila. Non - native and other less desirable trees and shrubs such as blackberry have replaced native riparian vegetation. Riprap also borders the river along many reaches. Urban development in and near the City has greatly reduced the vegetated buffer of the river and has encroached upon the banks. Flooding and drainage problems associated with this urban development throughout the basin (including the levees constructed to address flooding) have degraded fish and other wildlife habitat in and along the river. Productive, good quality fish habitat, both in the main channel and in off - channel refuge, is generally lacking along the Green and Duwamish Rivers. Spawning gravel recruitment to the Green /Duwamish River in this area has been diminished due to the comprehensive effects of urban development, in particular the diversion of the White River and the Cedar /Black River away from the Duwamish River. Little, if any, spawning habitat occurs in the river reaches within the City. The Puget Sound Salmon Recovery Plan calls for increased opportunities for levee set -backs to restore habitat within 200 feet of the Green /Duwamish River, particularly side - channel refuge habitat. In addition to the mainstem Green and Duwamish River channels, aquatic habitat is provided in the City of Tukwila's four major creek systems: Gilliam Creek, Riverton Creek, Southgate Creek, and Johnson Creek. The remainder of this section includes a description of the aquatic habitat available to fish in these four creek systems. 2.6.2 Gilliam Creek The lower reach of Gilliam Creek provides mostly rearing and possibly some scattered spawning habitat. Spawning gravels are covered by sediments deposited by upstream erosion and by historical construction activities. Habitat in the lower reach of Gilliam Creek is available to fish through the flap gate at the outlet of Gilliam Creek only under certain high -flow conditions, when the Green River water level is elevated but remains lower than the water level in Gilliam Creek. Several species of anadromous fish, including coho salmon, chinook salmon, and sea -run cutthroat trout, are reported to make use of the lower reach of Gilliam Creek, along the south shoulder of I -405 between the Green River and the I -5 /I -405 interchange (Washington Department of Fish and Wildlife [WDFW], 2010; Herrera, 2001). Two more partial fish passage barriers exist in the lower reach of Gilliam Creek. A State of Washington Department of Transportation (WSDOT) -owned culvert that conveys at least 1,000 feet of the creek under the south shoulder of I -405 is identified as a partial fish barrier (WDFW, 2010). Farther upstream, a log at the inlet of the WSDOT -owned culvert at the I -405 on -ramp observed in spring of 2011 appears capable of blocking fish passage. 2 -12 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2.0 DRAINAGE BASIN AND WATERSHED CHARACTERISTICS WDFW determined that several of the tributaries to upper Gilliam Creek provide some rearing habitat (WSDOT, 2007). Since the culvert underneath the I -5/1 -405 interchange is a total barrier to anadromous fish, it is likely that only resident fish such as cutthroat trout and sculpin are utilizing the available habitat in the upper reaches of Gilliam Creek at this time. Fish barriers do exist in the upper reaches of Gilliam Creek, including a WSDOT- owned culvert beneath SR 518 that conveys one of these tributaries that is identified as a total fish passage barrier. 2.6.3 Riverton Creek Both west and east forks of Riverton Creek are characterized by narrow, straight channels and long sections of culvert in their lower reaches. Both forks are considered fish - bearing. Coho salmon, Chinook salmon, and resident cutthroat trout are potentially present in Riverton Creek (WDFW, 2010; Entranco, 1997). Overall, Riverton Creek provides some limited rearing habitat for salmon, but no longer provides substantial spawning habitat. The flap gates at the outlet of Riverton Creek to the Duwamish River are impassable to fish during low flows plus somewhat impassable all other times. One of the flap gates is currently propped open as an interim solution. The East Fork of Riverton Creek just upstream of the SR 599 culvert is characterized by a wide, exposed, sandy, and silty streambed which provides fish passage but no spawning or rearing habitat. Upstream of that reach, a more than 2,000 linear feet (LF) culvert likely prevents at least some anadromous fish from accessing suitable habitat located in the upper reach between S 126th Street and S 128th Street, where good overhead cover from riparian plants, sufficient flows, and streambed gravel appear suitable for coho salmon spawning. Anecdotal evidence from a local resident during a February 2011 site visit suggests that anadromous salmon can and do access the east fork up to S 128th Street. The gradient upstream of S 128th Street is likely too steep for anadromous fish. Approximately 2,000 LF of restored channel in the West Fork of Riverton Creek just upstream of SR 599 has provided some spawning and rearing habitat. The culverts within this restored reach could fill with sediment from upper watershed erosion and surface water runoff, which could potentially block fish passage. A log jam in the upper portion of the restoration area may also be a partial fish passage barrier. Just upstream of the restored reach, a 20- foot -tall manmade waterfall prevents fish from passing upstream to S 126th Street. A private property owner owns and operates a fish hatchery and releases juvenile salmon at the base of the waterfall into the west fork at the upper end of the restored reach. Upstream of the waterfall up to S 126th Street, there is about 500 feet of potential fish habitat, though that reach also includes two total fish passage barriers. Fish would likely not be able pass upstream of S 126th Street because of a steep gradient, even if the waterfall and other nearby barriers were removed. However, this upper reach beyond S 126th Street has a cobble streambed that is likely supporting macroinvertebrates, a food source for fish downstream of the barriers. 2.6.4 Southgate Creek The East Fork of Southgate Creek begins as a relatively small channel just south of S 137th Street and flows north through a steep ravine, several culverts, and an asphalt -lined ditch WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2 -13 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN before it merges with the west fork. The West Fork begins as three smaller tributaries that collect flow from the hillside just west of 40th Avenue S and merge just upstream of S 133th Street. The West Fork then passes underneath S 133rd Street and 42nd Avenue S through more than 500 feet of culvert and merges with the east fork coming from a ditch along S 132nd Street. From there, the main stem of Southgate Creek extends under SR 599 through about 320 feet of culvert, a fish ladder, and large arch culvert into the Duwamish River downstream of the Black River confluence. Bank erosion from the combination of steep gradients and surface water runoff from urban development have deposited sediments in the lower reach, which have reduced effective culvert conveyance capacities and covered up salmon spawning gravels. The section of the main stem just downstream of the confluence of the West and East Forks is often completely blocked by sediment and debris. As in other urbanized streams, development has altered Southgate Creek's riparian buffer and natural channel alignment, resulting in increased channel incision, stream bank erosion, and degraded water quality. Rearing habitat is available in the main stem between SR 599 and S 132nd Street culvert. Rearing habitat is available in some small sections of the east fork along S 131st Place and S 134th Place. Rearing and some spawning habitat is available in the recently restored section of the west fork just upstream of S 133rd Street. Coho salmon are potentially present in Southgate Creek, according to WDFW, and resident trout or and other types of non - anadromous fish are likely present. The fish ladder at the SR 599 culvert likely is a fish barrier to anadromous fish during low stream flows. During a February 2011 site visit, juvenile salmon were observed in the section of the east fork along 5 131st Place, which are regularly released into the stream by a nearby homeowner, according to local residents and City of Tukwila staff. Fish are unlikely to be present in the West Fork of Southgate Creek upstream of Macadam Way S due to the steep gradient. Some resident fish may use the upper reaches of the east fork within Southgate Park. 2.6.5 Johnson Creek The Johnson Creek flap gate and outfall to the Green River, once partial blockages to fish passage, were replaced in 2011 with a fish - passable structure as part of the mitigation for the proximate commercial development. No other barriers to fish passage were identified in Johnson Creek. Also as part of the commercial development, the lower reach of Johnson Creek was reconstructed and now provides aquatic habitat opportunities. A revised aquatic habitat assessment should be performed once the commercial development in the Johnson Creek Basin is completed. 2.6.6 Mill Creek The Mill Creek drainage basin is the area east of the Green River north of S 190th Street and west of 72nd Ave South. This area flows into the Duwamish River and/or south and east into the Mill Creek basin within the City of Kent. All drainage conveyance is piped. No natural channels exist in this basin within the City of Tukwila. 2 -14 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2.0 DRAINAGE BASIN AND WATERSHED CHARACTERISTICS Mill Creek flows north from the City of Kent into the City of Renton, then discharges into the Green /Duwamish River within the City of Renton. Habitat opportunities and problems within the Mill Creek drainage within the City of Kent are identified in the Kent Surface Water Comprehensive Plan, likewise for those opportunities and problems within the City of Renton. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 2 -15 3.0 Regulations and City Policies This section contains a description of the current and anticipated future surface water regulations applicable to the City of Tukwila's surface water management program. In addition, potential City of Tukwila surface water management program improvements are identified that contribute to regulatory compliance. Appendix C contains the detailed information in support of this Section 3. 3.1 Applicable Surface Water Regulations Regulatory changes have occurred since preparation of the 2003 City of Tukwila Comprehensive Surface Water Management Plan. The changes most significant for Tukwila are with National Pollutant Discharge Elimination System (NPDES) Phase II permit. Regulations currently applicable to the City of Tukwila's surface water management program are described in detail in Appendix C. (Note that Green and Duwamish River flooding and flood protection are outside the scope of this Plan.) As was done in 2003 as part of that comprehensive planning effort, this 2013 Plan contains an evaluation, or gap analysis, of Tukwila's surface water management program against all relevant surface water management regulations. As a result of the gap analysis, this Plan contains recommendations for program improvements that need to be implemented to achieve compliance. In general, the City's surface water management activities support its regulatory compliance requirements and obligations, but there are some additional steps that must be taken to ensure regulatory compliance and to better coordinate environmental compliance activities across various City departments. Specific actions recommended to improve upon regulatory compliance are presented in Section 7 of this Plan. 3.2 Potential Regulatory Changes A number of changes in regulations relevant to surface water management are expected to occur in the next surface water planning cycle. Appendix C contains a detailed description of these anticipated changes. Changes to the NPDES Phase II Municipal stormwater permit and associated Total Maximum Daily Load (TMDL) program are anticipated, as well as the possibility of additional listings (or downgrading of existing listed species) under the Endangered Species Act (ESA). In general, these changes are expected to increase the City's obligations for surface water management, water quality, and aquatic habitat protection and restoration. Tukwila will need to accommodate such changes in its surface water management program, possibly with additional financial resources and /or additional staff time. Section 7 includes a section on recommendations to address these regulatory requirements anticipated in this next surface water planning cycle. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 3 -1 4.0 Surface Water Issues and Solutions This section summarizes existing surface water issues. These issues are organized by type of surface water issue: drainage, water quality, or aquatic habitat. Appendix D contains the detailed information in support of this Section 4. 4.1 Available Data and Information The following sources of information were used to identify drainage, water quality, and aquatic habitat issues: • Anecdotal and recorded information provided by City staff • Observations made during field visits by CH2M HILL and City staff • 2003 City of Tukwila Comprehensive Surface Water Management Plan • The following drainage studies: - 1993 Surface Water Management Comprehensive Plan - 1994 Gilliam Creek Detention and Water Quality Enhancements - 1996 Fostoria Basin Stormwater Quality Management Plan - 1997 Southgate Creek By -Pass Study - 2001 Gilliam Creek Basin Storm Water Management Plan. 4.2 Identified Surface Water Issues Localized drainage problems are the primary surface water concern for the residents of the City of Tukwila. Drainage issues arise on both public and private property because there are no storm drainage systems, the existing conveyance systems are damaged or in need of maintenance, or the existing conveyance systems have inadequate hydraulic capacity. Much of the development in Tukwila occurred previous to current stormwater flow control standards. In addition, as impervious surfaces are added, more stormwater runs off during storms, exacerbating existing problems. Water quality problems are evident in the Green and Duwamish River system and in each of the major creek systems within the City of Tukwila. The Green River and Duwamish River are listed as impaired on the 2008 Ecology 303(d) list for dissolved oxygen, temperature, pH, and fecal coliform. Untreated runoff from arterial streets with intensive traffic usage, areas of dense commercial development, parking lots in the Tukwila International Boulevard corridor and Westfield Mall area, and 1 -5 and I -405 contributes to these problems. All of Tukwila's creek systems are affected, including Gilliam, Riverton, Southgate, and Johnson Creeks. Runoff conveyed to the river via these creeks is contributing to the impaired water quality of the Green and Duwamish Rivers. Available aquatic habitat has been significantly reduced in the creeks that drain Tukwila due to the effects of development and the loss of riparian buffer areas. Uncontrolled runoff WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -1 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN flows coupled with steep slopes in the upper reaches of Gilliam, Southgate, Riverton, and Johnson Creeks cause channel erosion that in turn delivers sediments to the lower - gradient downstream reaches of these streams. Sediment deposition significantly reduces the conveyance capacity of these channels, restricts fish passage, and hinders the potential for salmonid spawning in these lower reaches. Better quality aquatic habitat in the lower reaches of all four streams in Tukwila would provide refuge to salmonids from high flows and predators in the Green and Duwamish Rivers. Several culverts are blockages to fish passage from the lower reaches to the upper reaches of each of the creek systems. Addressing these blockages to fish passage would provide salmonids access to aquatic habitat in the upper reaches of these systems. In addition, restoration of riparian buffer areas both in the upper and lower reaches of these creeks would reduce water temperatures, which is better for salmonids at all life cycles. Opportunities for salmon habitat restoration (and protection) are outlined in the WRIA 9 Salmon Habitat Plan (WRIA 9 2005). Table 4 presents a summary of the number of identified drainage, water quality, and aquatic habitat issues. Individual surface water issues are shown on Figure 6 and discussed in detail in Appendix D. TABLE 4 Surface Water Issue Summary Type of Surface Water Issue Number Water Aquatic Drainage Basin of Issues Drainage Quality Habitat Green/ Duwamish 9 X X X Gilliam Creek 5 X X Nelson Place / Long Acres 3 X X X P17 1 X Riverton Creek 3 X X Springbrook Creek 0 Southgate Creek 3 X X Johnson Creek 0 Mill Creek 0 City -wide 2 X X Totals 26 X X X This Comprehensive Surface Water Management Plan for Tukwila has outlined 26 specific surface water problems within the City of Tukwila. In addition to these specific 26, several smaller drainage issues have been identified by the City of Tukwila and have been included on the Small Drainage Project List maintained and frequently updated by City of Tukwila staff. The drainage issues on the Small Drainage Project List are addressed as a small drainage program. 4 -2 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX • v • • • . —.1 Lake Washington .fff, 1 ._ �' • • r Riverton Black River 19 • 4 ��jjIgjeison � Spriingbrook Ii • 180th Mill Creek 1 • Puget Sound • • • Surface Water Issues City of Tukwila Stormwater Pipe 1 1 King County Unincorporated Ml Drainage Basins • ▪ Other Municipalities • Outfall * Drainage • Drainage /Habitat • Habitat • Water Quality Water Quality/Drainage 0 1 2 Miles N FIGURE 6 Surface Water Issues City of Tukwila 2012 Surface Water Comprehensive Plan SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\FIGURE6 SURFACEWATERISSUES.MXD TJANTZEN 4/2/2013 11:48:55 CH2MHILL CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN 4.3 Menu of Solutions to Address Surface Water Issues This section outlines the menu of solutions that could be used to address the surface water issues identified in the City of Tukwila. No single type of action, activity, or project is a "one size fits all" fix to all of these identified problems. Some surface water problems have structural solutions, while others have programmatic (non - structural) solutions, and many have both programmatic and structural solutions. Implementing a diverse portfolio of solutions allows for different aspects of the issues to be addressed by different solutions. Potential solutions are divided into actions that would not involve construction or land acquisition, collectively referred to as programmatic approaches, and actions that would require capital projects and would be listed in the City of Tukwila Capital Improvement Program. The programmatic activities have the benefit of often being strategic rather than reactionary. Instead of fixing a single problem with a structural solution, programmatic alternatives often address a series of existing problems and are effective at preventing future problems. Often, capital (structural) solutions are most effective for single - location surface water problems and programmatic solutions are most effective for watershed -wide or other large - scale problems. Regulatory requirements (such as the NPDES Phase II permit) emphasize programmatic approaches to problems. Also, water quality problems can be targeted successfully using programmatic means such as source control measures. Sub - basin- or watershed -wide water quantity problems, such as increase in impervious surface runoff, can be addressed with programmatic solutions. Location - specific habitat, water quality, and water quantity issues can be addressed with capital projects. Using capital projects and programmatic solutions in tandem is the most effective method of addressing drainage, water quality, and aquatic habitat problems comprehensively. Because multiple sources contribute to the problems, multiple solutions targeting different sources and different aspects of sources are appropriate. Programmatic actions can provide overlapping benefits, thus addressing several pollution sources at once. However, capital projects can yield immediate, measurable results in a specific location, such as reduction of sediment load to the Green River from a specific parking lot. An additional benefit of capital projects is that the City can implement any number of individual capital projects in any given year depending upon funding availability. Both capital and programmatic solutions are discussed in the next sub - sections. 4.3.1 Programmatic Solutions The driving factor behind the comprehensive stormwater management plan is to comprehensively address drainage, water quality, and aquatic habitat issues identified in the City of Tukwila. The type(s) of surface water issues that could be addressed by individual programmatic solutions are summarized in Table 5. Note that many of these activities are required in whole or in part by the City's NPDES Phase II permit. The remainder of this sub - section discusses each of seven programmatic solutions in further detail. These seven types of programmatic solutions are education, incentives, changes to City policies or regulations, inspections and enforcement, illicit discharge detection and elimination, public involvement and compliant response, and operations and maintenance. 4 -4 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4.0 SURFACE WATER ISSUES AND SOLUTIONS TABLE 5 Surface Water Issue Types Addressed by Programmatic Solutions Surface Water Issue Type Required (in whole or in part) by Water Aquatic NPDES Phase II Program Element Drainage Quality Habitat Permit Education x x x x Incentives x x x Changes to City x x x Policies or Regulations Inspections and x x x Enforcement Illicit Discharge x x Detection and Elimination Public Involvement x x x x (including complaint response) Operations and x x x x Maintenance 4.3.1.1 Education Many surface water issues in Tukwila are caused by the everyday actions of people that live in or visit the City. While difficult, changing behavior patterns is a cost - effective programmatic solution to surface water problems. Establishing public knowledge of the link between activities within the watershed and ecosystem health is imperative for the success of these education programs. The educational topics listed below would supplement the current City of Tukwila education program: • Surface water runoff from existing residential lots • Surface water runoff from new developments • Improperly maintained surface water detention or treatment facilities • Proper maintenance of septic systems (where applicable) • Wastewater conveyance systems inspection and maintenance • Dog and cat pet waste disposal • Erosion management • Wildlife • Waterfowl (ducks and geese) • General awareness of receiving water health and fostering 'ownership' • Stream reach needs - get to know your backyard, Adopt -a- Stream programs Education has drainage, water quality, and aquatic habitat benefits. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -5 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN 4.3.1.2 Incentives Incentives could be considered as a way to more quickly and more effectively obtain the targeted benefits of education. Incentives are one step over on the education- incentives- regulations - enforcement spectrum. Incentives are most often financial. Possible incentives include: • Free "mutt mitts" for pet owners • Reduced surface water fee with on -site surface water management implemented on private property (with drain cleaning certification) • Free technical assistance for private property owners wishing to implement on -site surface water management (such as rain gardens or rain barrels) Incentives would have drainage, water quality, and aquatic habitat benefits. 4.3.1.3 Regulatory and Policy Changes Most existing drainage problems are best addressed with a capital project. However, programmatic solutions can be used to prevent future drainage problems by managing how new and re- development is conducted. Most of the water quality problems in Tukwila are caused by the activities of residents and visitors, including the way that people use the land. These pollutants cannot be removed practically by stormwater treatment facilities that are typically more effective at removal of point- source pollution. Therefore, protection of water quality is dependent on improved regulations to address the source of the pollutants. Possible changes to City policies or regulations include the following: • Require maximum potential infiltration on development and re- development sites • Require zero stormwater discharge from all new development • Establish a policy of no net increase in Effective Impervious Area in the City • Establish a policy of no net loss of forest cover in the City • Require annual inspections and corrections for septic systems (where applicable) • Require that all new roads, driveways, parking areas and walkways be constructed of pervious materials such as pervious asphalt, concrete, or pavers Changes to policies or to regulations at the state or national level are outside the scope of this Plan. Changes to City policies and regulations would have drainage, water quality, and aquatic habitat benefits. 4.3.1.4 Inspection and Enforcement Inspections are conducted during construction activities to ensure compliance with existing requirements. In Tukwila, these inspections might occur at less- than -ideal frequency due to 4 -6 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4.0 SURFACE WATER ISSUES AND SOLUTIONS lack of available personnel. In addition, enforcement is difficult. The inspection program would be enhanced and a more reliable and detailed recording system should be utilized. This recording system should be used to determine "hot spots" or "repeat offenders." Programmatic decisions affecting inspection and enforcement would incorporate input from the City's Planning and Development Services department. In addition to inspections of construction activities, Tukwila will need to develop an approach for inspections of privately -owned stormwater facilities such as detention ponds and vaults. Inspection and enforcement activities have drainage and water quality benefits. 4.3.1.5 Illicit Discharge Detection and Elimination Illicit discharge detection and elimination is an NPDES Phase II permit requirement. The permit requires the City to have an ongoing program to detect, remove, and prevent illicit connections, discharges, and improper disposal, including spills, into the surface water system. The permit requires full implementation of an illicit discharge and elimination program. Disconnecting homes from septic systems and connecting them to piped sewers is a structural solution aimed at reducing the risk of malfunctioning septic systems affecting receiving water quality. Illicit discharge detention and elimination would benefit water quality. 4.3.1.6 Public Involvement Public involvement can promote awareness of and foster a sense of responsibility for the health of the watersheds of Tukwila and of the greater Puget Sound, and help identify problems and solutions. Engaging citizens in the reporting and documenting of surface water problems through phone hotlines increases detection of problems. Environmental stewardship activities should be increased. Individually targeted groups should include children, students, adults, and visitors. Public involvement activities can be coordinated with the educational activities mentioned previously. Volunteers can perform stream buffer planting, become stream watchers, and plant trees both on their own property and in public spaces. Public Involvement would benefit drainage, water quality, and aquatic habitat. 4.3.1.7 Surface Water System Maintenance Currently, Tukwila City maintenance staff perform maintenance of the surface water system, including pipes, manholes, inlets and catch basins, ditches, open streams, and pump stations. Because of demands on limited resources, maintenance is too often done in response to a drainage complaint or issue rather than proactively. Proactive maintenance may also benefit water quality and aquatic habitat by reducing total sediment load to creeks. An example of this is cleaning out catch basins more often than required by the NPDES Phase II permit in sensitive areas such as near salmon- bearing creeks. Tukwila is required to ensure maintenance of private stormwater facilities in NPDES Phase II areas according to their NPDES Phase II permit. According to the permit, the City must WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -7 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN have a regular inspection plan for both public and private facilities. In addition to the inspection program, the City must have a program to work with private property owners to ensure that maintenance of the private facilities is occurring. Maintenance benefits drainage, water quality, and aquatic habitat. 4.3.2 Capital Project Solutions Capital projects implemented as part of a comprehensive capital improvement program can together address many of the surface water problems identified in the City of Tukwila. Capital projects have the potential to reduce and /or store stormwater volumes, reduce peak flows, improve water quality, and restore aquatic habitat. This section includes descriptions of the methods that can be utilized to address these surface water issues using capital projects. The type(s) of surface water issues that could be addressed by capital projects are summarized in Table 6. The remainder of this sub - section discusses each of the types of capital projects in further detail. Capital project types are organized by surface water issue type (drainage, water quality, and aquatic habitat). TABLE 6 Surface Water Issue Types Addressed by Capital Projects Capital Project Type Surface Water Issue Type Water Aquatic Drainage Quality Habitat Increase conveyance capacity x Provide drainage system (or re -route x existing) Infiltration x x On -site detention /retention x x Regional detention /retention x x Velocity Reduction (check dams, etc.) x x High flow bypass x x Impervious surface reduction x x Point source control x Water quality treatment x Conveyance system cleaning and x x inspection Land acquisition x x x Riparian buffer restoration / protection x x x Channel stabilization x Channel physical habitat restoration x Replacement of culvert or other x infrastructure to be fish passable 4 -8 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4.0 SURFACE WATER ISSUES AND SOLUTIONS 4.3.2.1 Drainage Capital projects meant to address altered hydrology (that is, water quantity) include infiltration, regional detention /retention, onsite detention /retention, reductions in impervious surface, velocity reduction, high -flow bypass facilities, dispersion, stream buffer restoration, and land purchase. The effectiveness of any of these alternatives can be limited by physical space constraints. The feasibility of any of these alternatives is also often limited by topography, soil conditions, and the presence of sensitive areas. Increasing Conveyance Capacity of a drainage network is often performed to alleviate localized drainage issues. Pipes are removed and replaced with a larger diameter pipe. Hydraulic and hydrologic analysis should be performed in order to assess downstream impacts of proposed conveyance capacity changes. Providing a drainage network where there is currently a formal system will provide conveyance of stormwater away from a location. Lack of a formal (that is engineered or planned) drainage network is common in areas developed before current stormwater standards. Infiltration is an extremely effective method to reduce stormwater runoff volumes and peak flows. Under pre - development conditions, a significant portion of the annual precipitation infiltrates into the ground. After development and the corresponding increase in impervious surfaces that prevent infiltration, much more of the annual precipitation runs off as stormwater. Promoting infiltration is a method to reduce the impacts of development by mimicking natural hydrologic processes. Infiltration effectiveness is a function of soil infiltration capacity. Many areas of Tukwila have top soils conducive to infiltration. When local soils are not conducive to infiltration, soils amended with organic material can be brought in and placed over native soils. Even if the native underlying soils have low infiltration capacity, the infiltrated water will use the storage available in the soil column of the amended soil layer until infiltration into the underlying layer is possible. Moisture retained in the amended soil layer is available for plant uptake, including lawns. During construction activities, it is common for the native top layer of soil to be stripped away. In this case, amended soils should be introduced rather than relying on the remaining native soils. Planting, then maintaining, a lawn on the remaining native soil will require watering and fertilizing that would not be necessary if the native top layer were still in place or if amended soils were brought in. Regional detention/retention is a plausible structural solution. Regional detention could be used to detain erosive peak flows. Total volumes of stormwater runoff can be reduced through retention via evaporation, plant uptake, and infiltration. In addition to implementation of new facilities, existing regional detention facilities can be retrofitted to promote capacity and capability. Onsite detention/retention and other site - specific measures are also effective at detaining peak flows and decreasing total volumes of stormwater runoff. Onsite detention and other site - specific measures on public, City -owned property are considered capital project and are therefore discussed in this section. Onsite detention and other site - specific measures on WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -9 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN private property are discussed in the programmatic solutions section under education, incentives, and regulations. That said, it may be feasible to use public funds to fund on -site detention on private property if the benefit is shared by a larger group than just the private property owner. Dispersion, for purposes of this discussion, is considered a type of on -site stormwater management Reductions in impervious surface can reduce runoff volumes and velocities. Low Impact Development (LID) regulations can promote reduced widths of newly constructed roadways and is covered in the regulations section (programmatic), but retrofitting existing infrastructure is a structural solution. Pilot projects for reducing road widths and using permeable pavements can be implemented within the City to address water quantity concerns. Conveyance system cleaning and inspection provides information as to the condition of the stormwater conveyance system that allows for prioritization of rehabilitation, repair, or replacement efforts. In addition, cleaning of the conveyance system can increase the effective conveyance capacity by removing accumulated sediment and other material. Water quality benefits may also be obtained by removing that sediment from the stormwater system. Stormwater runoff velocities can be reduced using check dams and vegetation in existing ditches. In addition, high -flow bypass facilities can be installed in areas that are prone to erosion under high flow regimes. Stream buffer restoration can reduce stormwater volumes via plant uptake and reduce stormwater velocities by adding roughness to the flow path. Land acquisition can be an effective method to reduce developed land surface and therefore reduce impervious surface, promote infiltration, and retain the natural tree canopy. 4.3.2.2 Water Quality The most effective methods to reduce pollutant loading to the City of Tukwila's receiving waters are controlling pollutants at the source and controlling stormwater flows (that is, peak flows and volumes). Water quality treatment can also be an effective method but effectiveness is often limited by available technology. Channel stabilization also has water quality benefits. Source control measures tend to be programmatic in nature rather than structural and are therefore addressed in the programmatic solution section. However, control of point source water quality problems is covered in this section. Alternatives geared towards reducing volumes and peaks of stormwater runoff discussed in the drainage section also have positive impacts on pollutant inputs by reducing erosion and erosive capabilities of stormwater and by reducing total stormwater inputs to receiving water bodies. These solutions include infiltration, regional or on -site detention or retention, impervious surface reduction, velocity reduction, stream buffer restoration, and land purchase. The effectiveness of water quality treatment as an alternative is limited by available technology. Total suspended solids (TSS) is relatively easy to remove but other pollutants such as nutrients and heavy metals are not. Particulate -bound copper can be removed via 4 -10 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4.0 SURFACE WATER ISSUES AND SOLUTIONS treatment, but dissolved copper is difficult to remove. Though particulate -bound copper can be removed using sedimentation and filtration, dissolved copper requires adsorption, precipitation, or separation. The pollutant removal capabilities of stormwater treatment is dependent upon the concentrations of pollutants entering the treatment facility. The lower the influent concentration, the harder it is to remove. The term "irreducible limits" refers to the concentration at which no more of a constituent can be removed. The irreducible limit depends on available technology. The higher the influent concentration, the easier the constituent is to remove. Channel stabilization can be used to reduce channel erosion propagated by increasing stormwater peak flows and volumes. This structural solution can prevent significant erosion and minimize the risk of increasing channel incision (that is, down - cutting). The selection of a preferred water quality solution is dependent upon pollutants of concern in the receiving water body. 4.3.2.3 Aquatic Habitat Structural solutions aimed at aquatic habitat restoration include replacing culverts, flap gates, or other structures that block fish passage, restoration of physical features of creek and river channels, and riparian buffer restoration and protection. Any of these solutions can aid in aquatic habitat restoration. This Plan contains an inventory of blockages to fish passage in the Gilliam, Riverton, Southgate, and Johnson Creeks. Restoring physical features of creek channels and protecting and restoring stream buffers also have water quantity and water quality benefits, in addition to aquatic habitat benefits. Note that habitat restoration or protection projects on the Green or Duwamish Rivers will require significant partnerships with regulatory agencies and with other municipalities such as King County. Land acquisition can be an effective method to reduce developed land surface and therefore promote infiltration, retain the natural tree canopy, and restore stream buffers. Retention of the natural tree canopy and restoration of stream buffers promote improvement of aquatic habitat. 4.4 Solutions to Tukwila's Surface Water Issues The purpose of this sub - section is to specify individual solutions to the surface water issues outlined earlier in this section. Table 7 outlines all major surface water issues identified during this planning effort. All of the surface water issues identified have been assigned one or more possible solutions. Each issue can be wholly or partially addressed by that, or those, solutions. Note that City -wide problems will need to be addressed by either a programmatic activity (such as a regulatory change) or else as a series (or program) of capital projects. Problems identified at specific locations may be addressed by a capital project, a programmatic action, or a combination of both programmatic and capital investment. A recommended solution is also shown in Table 7. In addition to the specific surface water issues shown in Table 7, several smaller drainage issues have been identified by the City of Tukwila and have been included on the Small WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -11 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Drainage Project List. The drainage issues on the Small Drainage Project List are addressed as a small drainage program. Note that both the programmatic activities and capital projects recommended as part of this Plan are described in Section 7 (Recommendations). Section 5 provides specific details of the operations and maintenance programmatic activities and Section 6 provides a listing of the capital projects. 4 -12 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4.0 SURFACE WATER ISSUES AND SOLUTIONS TABLE 7 Surface Water Issues and Solutions ID Problem Description Location Issue Drainage Type Basin Possible Solutions' Recommended Solution 1 Outfalls discharge directly All outfalls are potential candidates; to receiving water, no 48th Ave S and S 122nd are two treatment top candidates 2 Ponding in low spot, possible ponding on the east side of road 3 Dumping 4 Lack of off- channel salmon habitat along lower Duwamish 5 E Marginal Way S Stormwater Outfall 6 Duwamish River riverbank at S 104th St is eroding, causing failure of road shoulder and habitat degradation 7 Duwamish River riverbank at S 115th St is eroding, causing failure of road shoulder and habitat 49th Ave S and S Hazel Street S 114th St and 49th Ave S Duwamish River near light rail crossing North end of Tukwila, along east shore of Duwamish River; 4 outfalls proximate to S 87th Place Duwamish River right (east) bank at S. 104th St Duwamish River right (east) bank adjacent to S 115th St between 42nd Ave S and E Marginal Way S and adjacent to 42nd Ave S from Water quality All (City- wide) Drainage Green/ Duwamish Programmatic (inspections /enforcement, illicit discharge detection and elimination, maintenance) or capital (point source control, water quality treatment) Capital (increase conveyance capacity, retention /detention) Water Green/ Cleanup of dumped material quality Duwamish Habitat Green/ Capital (channel physical Duwamish habitat restoration) Drainage Green/ Duwamish Water quality Water quality Green/ Duwamish Programmatic (inspections /enforcement, illicit discharge detection and elimination, maintenance) or capital (retrofit system, abandon existing outfalls) Capital (channel stabilization) or close the road Green/ Capital (physical habitat Duwamish restoration; channel stabilization) Water Quality Retrofit Program (capital project) Move onto 2012 Small Drainage Project List To be addressed by others2 and City Code Enforcement Physical habitat restoration (capital project - Duwamish Gardens) Retrofit system / outfall(s) (capital project) To be addressed by others2; had been CIP project #99441205 To be addressed by others2 WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -13 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE 7 Surface Water Issues and Solutions ID Problem Description Location Issue Drainage Type Basin Possible Solutions' Recommended Solution degradation 8 53rd Ave S storm drain system has inadequate capacity 9 S 143rd St has no drainage system 10 Tukwila stormwater line discharges to WSDOT pipe, no access due to 1-405 widening 11 Andover Park 48 inch stormwater pipe in poor condition, possibly damaged S 115 St to Interurban Ave S. 53rd Ave S near S 139th S 143rd St, east of Interurban Ave; S 144th St, S 143rd Place, S 143rd S, east of Interurban Ave S between Interurban and Duwamish River, W. Of Duwamish, near Black River convergence Andover Park W at Gilliam Creek Andover Park W 12 Gilliam Creek flapgates as Outlet of Gilliam Creek to Green fish barrier River - partial fish blockage 13 Christensen Rd 12" pipe is undersized (replace with 18 ") 14 Gilliam Creek culvert at 42nd Ave SE is undersized Christensen Rd Gilliam Creek crossing at 42nd Ave SE (between S 154th and Hwy 518) Drainage Green/ Capital (increase Duwamish conveyance capacity, provide drainage system, detention /retention) Drainage Green/ Capital (provide drainage Duwamish system) Drainage Green/ Capital (re -route drainage Duwamish system) Drainage Gilliam Capital (increase effective Creek conveyance capacity) Drainage/ Gilliam Capital (modify /remove to habitat Creek allow fish passage) Drainage Gilliam Capital (increase capacity) Creek Drainage/ Gilliam habitat Creek Capital (increase conveyance capacity, replacement of culvert to be fish - passable) Increase conveyance capacity (capital project) Provide drainage system (capital project) Re -route drainage system (capital project) No capital project at this time; address once collection system has been clean and inspected; had been CIP project #98641217 retrofit for fish passage; provide flood protection (capital project) Increase capacity (capital project) Replace culvert (capital project) 4 -14 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4.0 SURFACE WATER ISSUES AND SOLUTIONS TABLE 7 Surface Water Issues and Solutions ID Problem Description Location Issue Drainage Type Basin Possible Solutions' Recommended Solution 15 Northwest Gilliam Storm Drainage System has inadequate capacity - S 152nd and S 148th 16 Cleaning /Inspection of Stormwater Conveyance 17 Storm Lift Station No. 15 improvements 18 Permanent home for soils reclamation facility 19 No functional outlet to drainage network at Nelson /Longacres 20 Former river oxbow has bren blocked off from River 21 Storm system along E Marginal Way is bad setup, causes ponding 22 Fish habitat accessibility issues in Riverton Creek culvert 23 Riverton Creek Flap Gate From 42nd Ave S to Tukwila International Blvd S 146th St, S 148th St, S 150th St, S 152nd St Various - commercial area at Mall and surrounding Near Claim Jumper - 5880 S 180th Vactor waste dump site / decanter facility, currently using an area near Nelson Place Area bounded by SR 181, Green River, Burlington Northern RR, and Strander Blvd Nelson farm property between Green River and W. Valley Highway E Marginal Way between SR599 ramp and S 124th St E Marginal Way south of SR599 Riverton outfall into Duwamish Drainage Gilliam Capital (conveyance Creek capacity, re -route existing drainage system, detention /retention, high flow bypass) Water All (City- Capital (conveyance system quality / wide) cleaning and inspection) drainage Drainage P17 Capital (needed upgrades, updating) Water Nelson/ Capital (land acquisition for quality Longacres soils reclamation facility) Drainage Nelson/ Capital (provide drainage Longacres system, on -site detention /retention) Habitat Nelson/ Capital (channel physical Longacres habitat restoration) Drainage Riverton Capital (increase Creek conveyance capacity, re- route drainage, detention, high flow bypass) Habitat Riverton Capital Creek (removal /replacement of fish - blocking culvert) Habitat Riverton Capital (modify /remove to Increase capacity (capital project) Conveyance system cleaning and inspection (capital project) Upgrade pump station (capital project) Land acquisition (capital project) Provide outlet to drainage system (capital project) Restore Nelson Salmon Habitat Side Channel (capital project) Proximate to Riverton Creek culvert (below), so addressed together Conveyance system cleaning and inspection (capital project) Remove flapgate (capital WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 4 -15 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE 7 Surface Water Issues and Solutions ID Problem Description Location Issue Drainage Type Basin Possible Solutions' Recommended Solution is partial fish passage River barrier 24 S 146th St pipe and 35th ave s drainage - needs additional capacity S 146th St between Military Rd S and Pac Hwy S 25 Sediment/clogging issues S 131st St near 44th Ave S proximate to Southgate Creek 26 Historical landslide - road S 137th St at 44th Ave S closed Drainage Drainage, water quality Drainage, water quality Creek Southgate Creek Southgate Creek Southgate Creek allow fish passage) Capital (increase conveyance capacity, detention /retention, high flow bypass) Regrading of wetlands on private property by private property owner Capital (complete channel stabilization and riparian buffer restoration) project) Increase conveyance capacity (capital project) To be addressed by others2 No capital project at this time; monitor status and review during next planning period Notes: 1 Possible solutions address the surface water problem in whole or in part 2 Problem to be addressed by others because responsibility /opportunity lies in other City department or with other jurisdiction 4 -16 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 5.0 Capital Improvement Projects This section summarizes the eighteen capital improvement projects recommended for inclusion into the City of Tukwila's capital improvement program. These capital projects are organized by fund (412 Fund for drainage and water quality shown in Table 8 and 301 Fund for fish habitat shown in Table 9). Figure 7 shows the locations of each of these capital projects. Appendix E contains the details for each capital project, including cost estimates. 5.1 412 Fund (Drainage and Water Quality) TABLE 8 Drainage and Water Quality Capital Projects - 412 Fund ID Project Name 98641222 S 143rd St storm drain system Basin Estimated Total Project Cost (March 2012 Dollars) 98741202 Nelson /Longacres - Phase I I 98941202 Christensen Rd. pipe replacement 99341208 Gilliam Creek 42nd Ave S culvert 99441202 Soil Reclamation Facility 90341206 Northwest Gilliam Storm Drainage System 90341213 53rd Ave S storm drain system 90341214 S 146th St pipe and 35th Ave S drainage 91041203 Storm Lift Station No. 15 Improvements 91041204 E. Marginal Way S Stormwater Outfall 91241201 Water Quality Retrofit Program 91241202 Tukwila Pkwy /Gilliam Cr Outfalls 91241203 Tukwila Urban Center Conveyance Inspections 91041204 E. Marginal Way Conveyance Inspection Green/ Duwamish River Nelson /Longacres Gilliam Creek Gilliam Creek Nelson /Longacres Gilliam Creek Green/ Duwamish River Southgate Creek P17 Green/ Duwamish River Green/ Duwamish River Gilliam Creek Gilliam Cr. /P17 Riverton Creek $1,096,000 $678,000 $327,000 $702,000 $3,504,000 $1,978,000 $1,557,000 $882,000 $698,000 $772,000 $287,000 $278,000 $541,000 $85,000 WBG031611103411 SEA\TU KW I LASURFACEWATERCOMPPLAN _FINAL_V2. DOCX 5 -1 f 0 =.Green /Duwamish 19104120 v Lake Washington • 1 • •` 1 ( •`� • . j •-,.� L.�._. -0 • 4 4 Black River Nelson - - -- - - -- Springbrook • Mill Creek • Puget Sound �vJ ,ceec\ Capital Improvement Projects * Drainage A Drainage /Habitat • Habitat • Water Quality • Water Quality/Drainage + Water Quality/Drainage /Habitat 0 1 2 Miles Johnson City of Tukwila 1! King County Unincorporated • Other Municipalities IIIIIIII� • Stormwater Pipe Drainage Basins Outfall N FIGURE 7 Capital Improvement Projects City of Tukwila 2012 Surface Water Comprehensive Plan SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS\ LAYOUT \FIGURE? CAPITOLIMPROVEMENTPROJECTS.MXD TJANTZEN 4/2/2013 11:54:45 CH2MHILL 5.0 CAPITAL IMPROVEMENT PROJECTS 5.2 301 Fund (Fish Habitat) TABLE 9 Fish Habitat Capital Projects - 301 Fund Estimated Total Project Cost (March 2012 ID Project Name Basin Dollars) 90330104 Nelson Side Channel Nelson /Longacres $1,497,000 90630102 Duwamish Gardens Green/ Duwamish $3,000,000 99830103 Riverton Creek Flap Gate Riverton Creek $946,000 Removal 99830105 Gilliam Creek Fish Barrier Gilliam Creek $816,000 Removal WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 5 -3 6.0 Operations and Maintenance This section contains a description of the operations and maintenance activities applicable to the City of Tukwila's surface water management program. 6.1 Surface Water Maintenance Activities The operations and maintenance of existing surface water assets is an important part of the City's surface water management program. Surface water Operations and Maintenance (O &M) staff perform the following: • Respond to citizen complaints regarding surface water problems • Observe and document new and existing surface water issues • Maintain and operate surface water assets (facilities, features, etc.) Tukwila's surface water O &M program has well - established guidelines for its various activities. These activities are based on previous experience and institutional knowledge and are optimized for the available maintenance crew and equipment resources. 6.2 Regulatory Compliance The City, businesses and residents of Tukwila are involved in activities that could potentially affect surface water. Water quality impacts from these activities can be offset by best management practices (BMPs). Many water quality BMPs are currently being implemented by the City in its O &M work in accordance with the City's NPDES stormwater permit. The City should consider enhancements to its surface water O &M program related to NPDES compliance: • Expand and enhance documentation program for compliant /complaint response, location of surface water 'hot spots' (for drainage and water quality), and maintenance performed; consider implementing a GIS -based tracking tool • Develop a vactor decant policy and locate and secure a permanent site to decant solids from vactor and street sweepings; perform a 'benchmarking' study of proximate surface water utilities to characterize what other utilities are doing with decant solids 6.3 Surface Water Maintenance Policies Within the boundaries of the City of Tukwila, numerous privately -owned residential surface facilities exist. Many if not most of these privately -owned residential surface water facilities are not maintained as they should be to maintain designed performance. The City of Tukwila needs make a policy decision regarding maintenance of these surface water facilities. In making this decision, the City should consider currently available surface water O &M staff and equipment resources and the cost of adding additional resources to maintain these privately -owned surface water facilities. The City needs to answer the following questions to inform their decision: WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 6 -1 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN • Existing residential Stormwater facility built by developers (or redevelopers), is it public or private? • When a new residential development installs a stormwater facility, is it public or private? Once these questions are answered, the City can then decide between the following options: • All residential stormwater facilities publically owned and publically maintained • All residential stormwater facilities privately owned, publically maintained (private owner charged a fee for the City to maintain) • All residential stormwater facilities privately owned, privately maintained (with corresponding enforcement program) A possible option would be to increase the stormwater fee dramatically for owners served by a private residential stormwater facility, then have the private stormwater facility owner prove it is being maintained adequately, and in turn have a reduced stormwater fee (back to the original rate). Whatever the City chooses, it must consider the impacts to required number of maintenance staff FTEs that would be required. 6 -2 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 7.0 Recommendations This section contains a summary of the recommendations made in this Plan for the City of Tukwila's surface water management program. 7.1 Recommended Activities 7.1.1 Capital Projects Section 5 of this Plan outlines the eighteen (18) individual capital projects recommended in this Plan. Of the 18, there are fourteen (14) recommended for implementation using the 412 fund and four (4) recommended for implementation using the 301 fund (Tables 8 and 9, respectively). Not all capital projects are recommended for implementation in this surface water planning window, due to funding availability. These remaining capital projects represent the continuing need for capital improvements in the City of Tukwila in order to achieve surface water goals. The City of Tukwila should consider this list of unfunded capital projects when making investments in other arenas (such as transportation) or when identified possible outside funding sources (such as grants or loans). This list will likely be a starting point for the next round of comprehensive surface water planning. 7.1.2 Programmatic Solutions and Policies This sub - section contains a summary of the recommended improvements to Tukwila's Surface Water Management Program needed in order to more fully comply with applicable regulations. These recommendations are also shown in Section 7 of the Plan. 7.1.2.1 Education Increase opportunities for public involvement in environmental stewardship activities; reach out to children, students, adults, and visitors. Develop and disseminate information to the public. 7.1.2.2 Incentives No recommendations at this time. 7.1.2.3 Regulatory and Policy Changes The City of Tukwila should update its SEPA ESA screening checklist to include Coastal - Puget Sound bull trout and Puget Sound steelhead The City of Tukwila has implemented capital improvement projects that restore fish habitat for ESA - listed species but should identify, plan, and implement more habitat restoration projects, in accordance with the State Salmon Recovery Planning Act. The City should respond to any new and additional requirements in the next NPDES Phase II permit cycle, which will likely include requirements for water quality monitoring and implementation of low impact development where feasible. In addition, the City should WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 7 -1 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN keep track of possible modifications to its NPDES stormwater permit over future cycles to include TMDL requirements on the Green and Duwamish Rivers. The City should make a policy decision regarding responsibility for maintenance of private residential stormwater facilities. The City needs to answer the following questions to inform their decision: • Existing residential Stormwater facility built by developers (or redevelopers), is it public or private? • When a new development installs a residential stormwater facility, is it public or private? Once these questions are answered, the City can then decide between the following options: • All residential stormwater facilities publically owned and publically maintained • All residential stormwater facilities privately owned, publically maintained (private owner charged a fee for the City to maintain) • All residential stormwater facilities privately owned, privately maintained (with corresponding enforcement program) A possible option would be to increase the stormwater fee on privately maintained residential stormwater facilities dramatically, then have the private stormwater facility owner prove it is being maintained adequately, and in turn have a reduced stormwater fee (back to the original rate). Whatever the City chooses, it must consider the impacts to required number of maintenance staff FTEs that would be required. 7.1.2.4 Inspection and Enforcement The City should plan for periodic updating of City's surface water system inventory. This inventory should include new infrastructure brought on -line since previous update (such as for new and re- development). The City should complete inspections of the City's stormwater system. As needed, complete cleaning of stormwater lines in order to allow inspections to occur. The City should perform an inventory (and plan for periodic updates) of private stormwater facilities within City boundaries. The City should enhance its inspection program to reduce noncompliance with BMP requirements and water quality violations. The City should identify, document, and implement procedures for characterizing, tracing, and removing illicit discharges. The City should develop and carry out systematic inspections of construction sites then document inspections and any enforcement actions. 7.1.2.5 Public Involvement Hold public meeting and public comment period on this Surface Water Comprehensive Plan. See related activities under 'education' within this Recommendations Section 7. 7 -2 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 7.0 RECOMMENDATIONS 7.1.2.6 Surface Water System Maintenance Develop a permanent vactor waste treatment facility or reach an agreement with another municipality to use an existing facility. Perform more robust documentation of inspections, maintenance activities, compliant response, etc. Enhance tracking and reporting to ensure maintenance, inspections, and enforcements are conducted and documented adequately. 7.1.2.7 Habitat Manager Hire a 'habitat manager' to focus on habitat protection and restoration within the City of Tukwila, assisting in implementation of the WRIA 9 Salmon Recovery Plan (WRIA 9 2005). The benefit would be that the City would have a qualified person dedicated to this effort and available for grant funding applications and permitting. The cost of this additional FTE could come from a combination of parks and from the surface water fee. With a dedicated person, the City would be more likely to obtain outside grant and loan funding for habitat projects. It's also possible that this position could pay for itself through outside funding. 7.2 Schedule for Implementation The City will determine a schedule for implementing the recommendations in this Plan. The City should consider implementing all of the programmatic recommendations in the next few years. While the City is budget- limited in implementing capital projects, it is recommended that the City implement at least one capital project per year to address the backlog of capital projects and to keep up with the rate of new capital projects being developed. Funding the capital projects and the programmatic recommendations in this plan will meet regulatory requirements and maintain current level of service. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 7 -3 8.0 References CH2M HILL. 2003. City of Tukwila Comprehensive Surface Water Management Plan. Prepared by CH2M HILL, Inc. Prepared for the City of Tukwila. November. Washington Department of Ecology (Ecology). 2006. Water Quality Standards for Surface Waters of the State of Washington - Chapter 173 -201A WAC. Publication No. 06 -10 -091. Lacey, Washington. Ecology 2010. 2008 Washington State Water Quality Assessment. http: / /www.ecy.wa.gov/ programs /wq /303d /2008 /index.html accessed on November 17, 2010. Entranco, Inc., et al. 1997. Riverton Creek Stormwater Quality Management Plan: Water Quality, Stream Habitat, and Flood Control. Prepared by Entranco Inc., Taylor Associates Inc., and Envirovision Inc. Prepared for the City of Tukwila. November. Herrera Environmental Consultants, Inc. 2001. Gilliam Creek Basin: Stormwater Management Plan. Prepared for the City of Tukwila. March. City of Tukwila. 2010. Infrastructure Design and Construction Standards. April. Washington Department of Fish and Wildlife (WDFW). 2010. Fish Passage Barrier Inventory Geodatabase. Accessed via email by Brian Benson, WDFW Habitat Program, on January 14, 2011. Washington State Department of Transportation (WSDOT). 2007. SR 518 SeaTac Airport to 1- 5/1 -405 Interchange Widening Project: Culvert Mitigation. February. Water Resource Inventory Area. (WRIA). 2005. Salmon Habitat Plan: Making Our Watershed Fit for a King. August. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX 8 -1 APPENDIX A Map Book • Green /Duwamish( C1\ C2 D3 Riverton ri2 Southgate • J k • F5j _ j Drainage Basins Maintenance Zone 1 Maintenance Zone 2 Maintenance Zone 3 Maintenance Zone 4 Maintenance Zone 5 WG2 H2 ---. 1151 15 G3 � Gilliam H3 Green /Duwamish (o, \? H4 , 5 1• l'alson _ r' 13 14 P17 J4 Mill Creek •-��, -I Sprigbrook Johnson City of Tukwila Surface Water Map Book Index SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\MAPBOOK6.MXD TJANTZEN 4/2/2013 07:49:16 - -1• I■._. • — �- -- Drainage Basins Maintenance Zone 1 Maintenance Zone 2 Maintenance Zone 3 Maintenance Zone 4 Maintenance Zone 5 Tukwila Boundary Parcels Buildings Pavement & Sidewalks Park Fish And Wildlife Habitat Ponds & Wetlands Stormwater Pump Station Stormwater Detention Pond Closed Pipe Culvert Ditch Stream Trench Drain Vault Pipe Sewer Pipes A Outfall: Trash Rack not Present, or Unknown A Outfall: Trash Rack Present "Other" Type Catch Basin Catch Basin 1 Infiltrate Catch Basin 2 Infiltrate Catch Basin Vault Inlet Basin Type 1 Catch Basin Type 1 Catch Basin Flow Restrictor Type 1 Catch Basin Pollution Control Type 2 Catch Basin Type 2 Catch Basin Channel Type 2 Catch Basin Flow Restrictor Type 2 Catch Basin Pollution Control Unknown or Not Assessed Yard Drain Catch Basin Sewer Manholes IB F P c F P Y City of Tukwila Surface Water Map Book Legend SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 B1 1 inch = 500 feet drml �m F4 Mm G4 Ey _H4� 14 E 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page Al SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 i1 Allmi tra,A.co �m F4 Mm G4 Ey 111 14 E Iur 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page A2 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 Al A2 0 n i7 1 1 11 T }y .li -1,44114 S 94th PI 0 v 24 -ft EMI �m F4 Mm G4 Ey E® H41� 14 ®I C1 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page B1 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 A2 fib G" traall ® 1 El m F4 L G4�y ME1N H4 1 14 ®I 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page B2 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 B1 B2 fib G" D kg 41111 ® 1 �m F4 L G4�y ME1N H4 14 ®I 1 inch = 500 feet 0 200 400 600 CCI Feet D2 City of Tukwila Surface Water Map Book Page C1 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 U B2 ■ • oct b�dTP \p ,306 00\ '` Boeing,Access Rd cti ;a9 D2 D3 k°i1L2 MEM �m F4 L G4�y MB1N H4 14 ®I Iur� N 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page C2 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 CV 0 D3 L 3/ MEM Mm F4 L G4 IM® H41� 14 ®I 1 inch = 500 feet 0 200 400 600 CCI Feet D4 City of Tukwila Surface Water Map Book Page C3 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 C1 C2 1 inch = 500 feet 4771 MIME �m F4 L G4�y ME1N H4 14 ®I Iur 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page D2 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 E4 0 C2 C3 47274 I D3 2 MIME m F4 L MEG4�y H4 IN 14 ®I Iur� N 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page D3 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 C3 E4 fill' 1 bp 477 D2 co mom m F4 L G4 M ®H4 IN 14 ®I 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page D4 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 D2 D3 F2 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page E2 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 m ca F3 D4 rfl South Base AcRd•df N S 122nd St }} i l 1 1 Y -al or) al 7r'. -..III 'S 124th St c— P 1 • W4 co 'o wd T k C t x - 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Bicentennial Park —� at _L 12 in d" StranderBlvd 30_., ._ 4 -ra r an N 1 inch = 500 feet 0 200 400 600 CC1Feet City of Tukwila Surface Water Map Book Page 15 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\MAPBOOK6.MXD TJANTZEN 4/2/2013 07:49:16 24 " -inY • Midland Dr. 0 CD S 180th ,St • .: � -,.� ■ ll rc�� 18 -inr. O. Segale Park D Dr S'%. 'F i' ' ` __ I.. 4 lko Ell 1 D3 �� NEM �m F4 �G3 G4� H3 H4 Ei 14 J5 3 N 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page J4 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\MAPBOOK6.MXD TJANTZEN 4/2/2013 07:49:16 Unnamed Park Via • • • Aft- G . r o d<; F f F r• • 1. Saxon Dr, o 4 1 -4 S 180th S (1)' SW 43rd•St __ • jr.. • or • t. .....,. F...,,,,/ ,<,, •:, rii, • -4 ---- lko 1 tsD3 �� ERIE F4 MB el ®H4 YCi �, I4 ®I IM it N 1 inch = 500 feet 0 200 400 600 Feet City of Tukwila Surface Water Map Book Page J5 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\MAPBOOK6.MXD TJANTZEN 4/2/2013 07:49:16 fill 3/ a.21 ® 1 �m F4 L G4 MB H41N 14 N 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page K3 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 fib Ell A NEM man D3 �� �m F4 �G3 G4� H3 H4 14 (�J5 N 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page K4 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\MAPBOOK6.MXD TJANTZEN 4/2/2013 07:49:16 fill 3/ DI Ill D3 a MEM m F4 M ®G4 Ey E® H41� 14 ®I K3 Z m L4 N 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page L3 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 L 3/ drwl �m F4 L G4�y ME1N H4 14 ®I 1 inch = 500 feet 0 200 400 600 CCI Feet City of Tukwila Surface Water Map Book Page L4 SEA \ \SIMBA\ PROD\ TUKWILAWACITYOF1412954SWCOMPPL \GIS \LAYOUT \MAPBOOK5.MXD TJANTZEN 5/15/2012 14:01:10 APPENDIX B Drainage, Water Quality, and Fish Habitat Characterization (Supporting Information for Plan Section 2) APPENDIX B Drainage, Water Quality, and Fish Habitat Characterization This Appendix B contains the drainage, water quality, and fish habitat characterization for the City of Tukwila. The information presented here is summarized in Section 2 of this Surface Water Comprehensive Plan. This Appendix is organized by drainage basin, with the following eight drainage basins located wholly or partially in the City of Tukwila: • Green /Duwamish River Mainstem • Gilliam Creek • Nelson Place - Long Acres • P17 • Riverton Creek • Southeast Central Business District (CBD) • Southgate Creek • Johnson Creek Basin boundary delineation was based on information from field visits, the City Geographic Information System (GIS), and previously developed basin plans. The City of Tukwila is nearly finished with an inventory and mapping of the drainage network. Basin boundaries should be re- visited once this inventory and mapping is complete. Green /Duwamish River Mainstem Basin Drainage Characterization The Green /Duwamish River meanders from the southeast to northwest through the City of Tukwila. The Green /Duwamish River is tidally influenced along most of length of the river within the City of Tukwila. The Green /Duwamish River is called the Duwamish below the confluence with the Black River and is called the Green River upstream of that point. The flood and floodplain management of the Green /Duwamish River is outside of the scope of this surface water comprehensive plan. The Green /Duwamish River drainage basin shown in Figure B -1 has multiple outlets, or outfalls, into both the Green and Duwamish Rivers. This basin is almost entirely developed. Industrial areas, including portions of the Boeing Airfield, make up the development in the area north of the Riverton Creek Basin. The areas east of the Riverton and Southgate Creek basins and north of the Gilliam Creek basin are mostly residential. Foster Golf Course and Fort Dent Park are within this basin. The area east of the P17 basin is mostly commercial. City of Tukwila surface water pump stations #17, #18, and #19 are located within the Green Duwamish River Mainstem drainage basin (Figure B -1). WBG031611103411SEA\ TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -1 YY N▪ ormandy Park • Puget Sound • Des Moines Y Seattle f • r—" Green /Duwamish Y 4 • 7 '4„ Mercer Island `` • 44 `44 4! Lake Washington • 4 •"4 King County 0 0•110•0 • 4 King County Burien Black River MidT (�IIIlarn l„ talk`• I�I' - Nelson Springbrook SeaTac 99 unty PS 1 • • • • Johnson a King County COHNSON ▪ 11 tee`` Mill Creek \Jet._ Kent City of Tukwila 1.-1 King County Unincorporated • Other Municipalities N • 0 1 2 Miles Stormwater Pump Station Stormwater Pipe Drainage Basins • Outfall FIGURE B -1 City of Tukwila Drainage System City of Tukwila 2012 Surface Water Comprehensive Plan SEA \ \SIMBA\ PROJ\ TUKWILAWACITYOF\ 412954SWCOMPPL \GIS \LAYOUT\FIGUREB -1 DRAINAGESYSTEM.MXD TJANTZEN 4/2/2013 12:36:19 CH2MHILL APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION Water Quality Characterization In 2003, Ecology adopted a water use -based classification for state surface waters (RCW 173 -201A, Table 602) that determines the surface water quality standards applicable for that water body (RCW 173 -201A- 600(1)). The Duwamish River (below the confluence with the Black River) is classified as Salmonid Rearing /Migration Only and Secondary Contact Recreation. The Green River (above the confluence with the Black River) is classified as Salmonid Spawning /Rearing Only and Primary Contact Recreation. None of the tributaries to these rivers within Tukwila is listed in Table 602. Therefore the uses defined for these tributaries are the same as the Green River to which they discharge. Table B -1 shows the classifications for surface waters in the City of Tukwila. TABLE B -1 Use -based Classification for Surface Waters in City of Tukwila Water Body Use -based Classification (Source: RCW 173 -201A- 600(1)) Aquatic Life Uses Recreational Uses Duwamish River (Green /Duwamish River, Salmonid Secondary Contact downstream of confluence with Black River) Rearing /Migration Only Recreation Riverton Creek (to Duwamish River) Salmonid Secondary Contact Rearing /Migration Only Recreation Southgate Creek (to Duwamish River) Salmonid Secondary Contact Rearing /Migration Only Recreation Green River (Green /Duwamish River, Salmonid Primary Contact upstream of confluence with Black River) Rearing /Migration Only Recreation Gilliam Creek (to Green River) Salmonid Primary Contact Rearing /Migration Only Recreation Johnson Creek (to Green River) Salmonid Primary Contact Rearing /Migration Only Recreation Other Tukwila drainage basins (to Green Salmonid Primary Contact River): Rearing /Migration Only Recreation Nelson Place / Long Acres Southeast CBD P17 Ecology maintains a list of water bodies that do not meet water quality standards, known as the 303(d) List. The United States Environmental Protection Agency (EPA) approved the 2008 Water Quality Assessment 305(b) report and 303(d) list on January 29, 2009. This is the current water quality assessment and 303(d) list for the state of Washington. Four sections of the Green /Duwamish River within the City of Tukwila do not meet water quality standards according to the 2008 303(d) list. Both the Green River and Duwamish River are listed as Category 5 (at least one designated use is impaired) for dissolved oxygen, temperature, pH, and fecal coliform, based on water sampling and analysis. Figure B -2 shows the 303(d) listings for water bodies within the City of Tukwila and Table B -2 shows the 303(d) listings relevant for the City of Tukwila. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -3 ._., King County King County International Airport Seattle ;Mercer Island r Lake Washington Nme • • • King County or t Burien • • • • • • Seattle- Tacoma International Airport SeaTac • • Normandy Park • - -- Puget Sound King County See Table B -2 for all 303(d) listed parameters. Data from http: / /www.ecy.wa.gov/ programs /wq /303d /2008 /index.html Kent •' • 111100..-... -., 303(d) List Categories n City of Tukwila 5 4C _ 4B 4A 2 1 King County Unincorporated Other Municipalities Streams and Rivers 0 3 Miles FIGURE B -2 Ecology 303(d) Listed Water Bodies City of Tukwila 2012 Surface Water Comprehensive Plan SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \FIGUREB -2 303D.MXD TJANTZEN 11/14/2011 17:11:20 CH2MHILL APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION TABLE B -2 303(d) Water Quality Listings for Surface Waters within City of Tukwila Boundaries Water Body Listing Category Parameter Medium Duwamish River Duwamish River Duwamish River Duwamish River Duwamish River Duwamish Waterway Duwamish River Duwamish Waterway Duwamish Waterway Green River Green River Green River Green River Green River Green River Green River Springbrook (Mill) Creek 1 Ammonia -N 1 Fecal Coliform 2 Bis(2- Ethylhexyl) Phthalate 2 Dissolved Oxygen 2 Temperature 4A Ammonia -N 5 pH 5 Dissolved Oxygen 5 Fecal Coliform 1 Ammonia -N 1 pH 2 Bis(2- Ethylhexyl) Phthalate 4A Ammonia -N 5 Dissolved Oxygen 5 Fecal Coliform 5 Temperature 1 Ammonia -N Water Water Water Water Water Water Water Water Water Water Water Water Water Water Water Water Water In addition to Ecology's 303(d) listings, King County has collected monthly water quality data along the Green /Duwamish River for many years (King County, 2011). Two monitoring stations fall within the City of Tukwila: Duwamish River at E Marginal Way Bridge and Green River at West Valley Road. These data were reviewed for the period of 2003 through 2008. They reflect around 70 samplings and are the latest data available. The Duwamish station meets water quality standards for dissolved oxygen, pH, and fecal coliform. Temperature is exceeded in 11 percent of the total samples, during the months of July and August. For the Green River station, temperature is exceeded in 15 percent of the total samples, also during the same summer period. In addition, 15 percent of the dissolved oxygen samples from the Green River station fail to meet standards, mostly during the summer period. The lowest dissolved oxygen measurement at the Green River station was 7.0 milligrams per liter (mg /L). Fecal coliform and pH surface water quality standards were met at this station. Turbidity standards are expressed as an allowable increase over background conditions and the water quality data do not allow for a direct assessment. The maximum recorded turbidity at either station during this six -year period is around 70 Nephelometric Turbidity WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -5 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Units (NTUs) and that only four values at each station exceeded 10 NTUs, indicating relatively clear water conditions nearly all of the time. The northern -most portion of the City of Tukwila lies within the Lower Duwamish Waterway Superfund Site, designated by the EPA in 2001. King County, the Port of Seattle, and the cities of Seattle and Tukwila are working with the Washington Department of Ecology (Ecology) and the EPA to control sources of pollution in the Lower Duwamish Waterway. Decades of heavy industrial activity along both sides of the waterway have resulted in the accumulation of high levels of PCBs, polyaromatic hydrocarbons (PAHs), arsenic and other pollutants in the upland soils and within the waterway sediments (Windward Environmental, 2010). Dredging and capping projects in limited areas of the waterway have removed some of these pollutants and more removal actions are planned. Upland sources of these pollutants are also being addressed. Ecology is the lead agency for implementing source controls in the Lower Duwamish Waterway. In 2002 the entities listed above formed the Lower Duwamish Waterway Source Control Work Group to coordinate source control activities. The Norfolk Basin, located in the southern portion of the superfund site, lies partially within the jurisdiction of the City of Tukwila. This area is included in the Duwamish River Basin shown on Figure B -1. The Norfolk Basin discharges to the Lower Duwamish Waterway and includes both stormwater runoff and occasional combined sewer overflows. In 2007, the City of Tukwila signed a memorandum of agreement with the City of Seattle allowing the latter to inspect suspected contaminated sites in the Norfolk Basin that lie within the jurisdiction of the City of Tukwila. The City of Seattle has carried out sediment sampling and cleaning of storm sewers in the Norfolk Basin. Of the numerous chemical parameters analyzed in the storm sewers, phthalates and zinc consistently exceeded the cleanup screening level (CSL), above which adverse impacts on marine organisms would be likely. Total petroleum hydrocarbons were also consistently high. The City of Seattle removed sediment from the storm sewer serving Martin Luther King Way South prior to a recent sewer upgrade. In 2007, Ecology produced a Source Control Action Plan (SCAP) for Early Action Area 7 (the Norfolk Basin) (Ecology and Environment, 2007). The plan lists a number of potential upland sources of contaminants to the surface water system. Through the memorandum of agreement mentioned earlier, the City of Seattle is conducting inspections to determine whether cleanup measures should be carried out. The SCAP states that there is an incomplete mapping of the surface water system serving the Norfolk Basin. It identifies the need for a cooperative effort between the City of Seattle and the City of Tukwila to use available GIS and as -built storm sewer drawings to better delineate the surface water system. The EPA is sponsoring another round of storm drain sampling in 2011. The City has recently signed another agreement allowing continued inspection and sampling with the Norfolk Basin (Larson, 2011). Fish Habitat Characterization The Green / Duwamish River channel is significantly altered from its natural condition along most reaches in the City of Tukwila. Non - native and other less desirable trees and shrubs such as blackberry have replaced native riparian vegetation. Riprap also borders the river B -6 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION along many reaches. Urban development in and near the City has greatly reduced the vegetated buffer of the river and has encroached upon the banks. Flooding and drainage problems associated with this urban development throughout the basin (including the levees constructed to address flooding) have degraded fish and other wildlife habitat in and along the river. Productive, good quality fish habitat, both in the main channel and in off - channel refuge, is generally lacking (King County, 2000). Spawning gravel recruitment to the Green /Duwamish River in this area has been diminished due to the comprehensive effects of urban development, in particular the diversion of the White River and the Cedar /Black River away from the Duwamish River. Little, if any, spawning habitat occurs in the river reaches within the City. Gilliam Creek Basin Drainage Characterization The Gilliam Creek basin has a single outlet to the Green River through an outfall and flap gate located to the south of I -405. Most of the Gilliam Creek basin is located within the central region of the City of Tukwila, with the remainder (27 percent) located in the City of SeaTac. The basin has been almost fully developed except for the steep slopes above the I -5 corridor. The portion of the basin located north of 1 -405 and east of 1 -5 is mostly residential, with some commercial areas located along Southcenter Boulevard. Residential developments make up most of the basin west of I -5, with the exception of the Tukwila International Boulevard corridor which contains commercial development. Southcenter Mall and other commercial areas dominate the portion of the basin east of I -5 and south of I -405. Tukwila Pond is within the 25 acre Tukwila Pond Park located to the south of Southcenter Mall. Historically, this area drained north into Gilliam Creek via both subsurface and surface flow. As this area was developed, Tukwila Pond was formed. Currently, under normal flow conditions, Tukwila Pond drains to the south into the P17 basin then on to the Green River. A conveyance system built along Andover Park West in the mid -1980s provides overflow conveyance north towards Gilliam Creek. A gate valve installed at the discharge point to Gilliam Creek is usually closed. When open, the City of Tukwila has the capability to either allow Tukwila Pond to flow into Gilliam Creek when the pond is at high levels or to provide storage when the Green River is at high levels and backs water into the storm drain systems in the lower portion of the Gilliam Creek Basin. Figure B -1 shows the location of Tukwila Pond. Water Quality Characterization Gilliam Creek's use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because Gilliam Creek enters the Green River upstream of the confluence with the Black River. The water quality characterization for Gilliam Creek in this section is drawn from the stormwater management plan prepared for Gilliam Creek in 2001 (Herrera, 2001). Water quality data for the creek was collected in support of that study. No additional water quality data for the creek has been found subsequent to this study. Thus, the discussion in this section is drawn from that study. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -7 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN The creek water samples were taken at eight locations during three different storm runoff events in the fall of 1999. The data therefore reflect the effects of active stormwater runoff and cooler temperature conditions. In summary, temperature, dissolved oxygen, and pH (the latter with the exception of one sample) all met current state water quality standards. Turbidity was somewhat elevated, generally ranging from 25 to 50 NTUs. Similarly suspended solids were also only modestly elevated, generally ranging from 20 to 60 mg /L. Dissolved lead met applicable water quality criteria, as did nearly 90 percent of the dissolved zinc samples. About half of the samples failed to meet the dissolved copper criteria. Finally, nearly all of the fecal coliform samples were above the state water quality standards. The study noted that the two sites most frequently exceeding the criteria for zinc and copper both directly drained Highway 99 and appear to be heavily influenced by the high level of traffic and parking lots in the upper basin. Similar conditions exist in the lower reaches of Gilliam Creek near Southcenter Mall, but the dilution effects occurring in the lower portion of the basin may mitigate against higher metals concentrations in the creek. In a study that had been conducted several years prior, two creek samples were collected during summer baseflow conditions (June and September of 1997). Several samples taken during these months did not meet the state dissolved oxygen standard, with one sample recorded at 3.2 mg /L, well below the state standard of 6 mg /L. These samples also fell slightly below the pH standard. In September the measured stream temperature of 17.5 degrees Celsius barely fell below the state standard of 18 degrees. This suggests the likelihood that portions of the stream may exceed the state temperature standard during the warmer summer months Gilliam Creek flows into a section of the Green River that is on Ecology's 303(d) list for temperature, dissolved oxygen and fecal coliform. Thus the degraded water quality conditions in Gilliam Creek may be contributing to water quality problems in the Green River. Given both the age and the limited amount of water quality data available for Gilliam Creek, additional water quality data should be collected to determine if similar water quality conditions continue to persist in this creek. Fish Habitat Characterization Several species of anadromous fish, including coho salmon, chinook salmon, and sea -run cutthroat trout are reported to make use of the lower reach of Gilliam Creek, along the south shoulder of 1 -405 between the Green River and the 1 -5 /I -405 interchange (Washington Department of Fish and Wildlife [WDFW], 2010; Herrera, 2001). This lower reach provides mostly rearing and possibly some scattered spawning habitat. Spawning gravels are covered by sediments deposited by upstream erosion and by historical construction activities. Habitat in the lower reach of Gilliam Creek is available to fish through the flap gate at the outlet of Gilliam Creek only under certain high flow conditions, when the Green River water level is elevated but remaining lower than the water level in Gilliam Creek. WDFW has characterized this flap gate a partial fish passage barrier (WDFW, 2010). Two more partial fish passage barriers exist in the lower reach of Gilliam Creek. A State of Washington Department of Transportation (WSDOT) -owned culvert that conveys at least 1,000 feet of the creek under the south shoulder of I -405 is identified as a partial fish barrier (WDFW, B -8 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION 2010). Farther upstream, a log at the inlet of the WSDOT -owned culvert at the I -405 on -ramp observed in spring of 2011 appears capable of blocking fish passage. WDFW determined that several of the tributaries to upper Gilliam Creek provide some rearing habitat (WSDOT, 2007). Since the culvert underneath the I -5 /I -405 interchange is a total barrier to anadromous fish, it is likely that only resident fish such as cutthroat trout and sculpin are utilizing the available habitat in the upper reaches of Gilliam Creek at this time. Fish barriers do exist in the upper reaches of Gilliam Creek, including a WSDOT- owned culvert beneath SR 518 that conveys one of these tributaries that is identified as a total fish passage barrier. Figure B -3 shows the inventory of fish - blockages in the creek systems of Tukwila, including Gilliam Creek. Attachment A to this Appendix B contains a detailed inventory of barriers to fish passage within the City of Tukwila. Nelson Place — Long Acres Basin Drainage Characterization The Nelson Place - Long Acres basin is located east of the Green River on the eastern edge of the City of Tukwila (Figure B -1). The Renton city limits form the east boundary of the basin. Commercial developments line the West Valley Highway corridor. The areas east and west of the West Valley Highway corridor are mostly undeveloped. Runoff from the West Valley Highway and the area in the western part of the drainage basin drains directly into the Green River through numerous storm drainage outfalls. Runoff from the area east of the West Valley Highway drains to the open ditch and culvert system located on the east side of the basin adjacent to the Burlington Northern Santa Fe (BNSF) Railroad track. A 24 -inch- diameter pipe located under the BNSF tracks directs drainage from this series of open ditches and culverts east to drainage systems in the City of Renton. Figure B -1 shows the Nelson Place - Long Acres Basin in relation to the city boundaries and to the other drainage basins in Tukwila. Water Quality Characterization The Nelson Place - Long Acres drainage basin use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. No water quality data is available for this drainage basin. Fish Habitat Characterization The former alignment of the Green River, prior to construction of I -405 in 1962, extended through the Nelson farm property and into the property currently occupied by Homestead Studio Suites. Part of that former alignment has been filled, isolating a pond area and reducing off - channel habitat and floodplain connectivity in this reach of the river. Apart from along the mainstem Green River, which is described in an earlier section of this Appendix, no fish habitat was identified in this basin. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -9 Fish Passage Features =I City of Tukwila Barrier Status • King County Unincorporated ▪ N/A Stream ❑ None I=1 Drainage Basins II Partial • Potential • Total Attachment A Figures 0 1 2 3 Miles FIGURE B -3 Inventory of Fish Blocking Culverts City of Tukwila 2012 Surface Water Comprehensive Plan CFI2 SEA \\ SIMBA\ PROJ\ TUKWILAWACITYOF \412954SWCOMPPL \GIS \LAYOUT \FIGUREB -3 FISHBLOCKINGCULVERTS.MXD TJANTZEN 4/2/2013 12:43:59 MHILL APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION P17 Basin Drainage Characterization The P17 drainage basin is located south of the Gilliam Creek basin (Figure B -1). Approximately 60 percent of this basin is located within the City of Tukwila, with the remaining portion in the City of SeaTac. The basin is almost fully developed for the exception of the steep slopes adjacent to the I -5 corridor. The P17 basin includes a portion of the Tukwila South development site. Typically, flows from Tukwila Pond are routed through drainage basin P17. A drainage pipe adjacent to Andover Park West conveys pond outflow into the basin. As discussed earlier, drainage is routed north to Gilliam Creek when the gate valve at the overflow pipe to Gilliam Creek is open and the pond water level is elevated. The P17 drainage basin has multiple outlets, or outfalls, into the Green River. Runoff from the northern portion of the basin is routed to the P17 stormwater pump station located at the east end of Minkler Boulevard. This P17 pump station, owned and operated by King County, discharges to the Green River. The southern portion of the basin drains to the P17 pump station or directly into the Green River through a WSDOT outfall. City of Tukwila's surface water pump station #15 is located within this P17 drainage basin (Figure B -1). Water Quality Characterization The P17 drainage basin use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. No water quality data is available for this drainage basin. Fish Habitat Characterization Apart from along the mainstem of the Green River, which is described in an earlier section of this Appendix, no fish habitat was identified in this basin. Riverton Creek Basin Drainage Characterization The Riverton Creek basin is located in the northwest region of Tukwila. Nearly the entire basin is located within the City of Tukwila boundaries with the remaining portion of the basin in unincorporated King County and in the City of Sea -Tac. The basin is almost entirely developed except for about 50 acres of forested land west of Tukwila International Boulevard. Residential and commercial developments are located on the steep slopes in the southern and western portions of the basin. Light industrial developments are located in the valley floor in the northern portion of the basin. There are two major forks to Riverton Creek, named the East Fork and West Fork. The East Fork and West Fork of Riverton Creek merge just upstream of SR 599, and then pass underneath SR599 through approximately 300 feet of culvert, through about 1,000 feet of open channel and finally through two 48 -inch culverts (each with a flap gate) into the Duwamish River downstream of the confluence with the Black River (Figure B -1). WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -11 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Water Quality Characterization The Riverton Creek use -based classification is Salmonid Spawning /Rearing and Secondary Contact Recreation, because the drainage discharges to the Duwamish River downstream of the confluence with the Black River. No water quality data is available for this drainage basin. Fish Habitat Characterization The flap gates at the Duwamish River are impassable to fish during low flows plus somewhat impassable all other times. Both west and east forks of Riverton Creek are characterized by narrow, straight channels and long sections of culvert in their lower reaches. Both forks are considered fish - bearing. Coho salmon, Chinook salmon, and resident cutthroat trout are potentially present in Riverton Creek (WDFW, 2010; Entranco, 1997). Overall, Riverton Creek provides some limited rearing habitat for salmon, but no longer provides substantial spawning habitat. The East Fork of Riverton Creek just upstream of the SR 599 culvert is characterized by a wide, exposed, sandy and silty streambed that provides fish passage but no spawning or rearing habitat. Upstream of that reach, a more than 2,000 linear foot (LF) culvert likely prevents at least some anadromous fish from accessing suitable habitat located in the upper reach between S 126th Street and S 128th Street, where good overhead cover from riparian plants, sufficient flows, and streambed gravel appear suitable for coho salmon spawning. Anecdotal evidence from a local resident during a February 2011 site visit suggests that anadromous salmon can and do access the east fork up to S 128th Street. The gradient upstream of S 128th Street is likely too steep for anadromous fish. Approximately 2,000 LF of restored channel in the West Fork of Riverton Creek just upstream of SR 599 has provided some spawning and rearing habitat. The culverts within this restored reach could fill with sediment from upper watershed erosion and stormwater runoff, which could potentially block fish passage. A log jam in the upper portion of the restoration area may also be a partial fish passage barrier. Just upstream of the restored reach, a 20- foot -tall manmade waterfall prevents fish from passing upstream to S 126th Street. Juvenile salmon are released from a city- operated fish hatchery at the base of the waterfall into the west fork at the upper end of the restored reach. Upstream of the waterfall up to S 126th Street, there is about 500 feet of potential fish habitat, though that reach also includes two total fish passage barriers. Fish would likely not be able pass upstream of S 126th Street because of a steep gradient, even if the waterfall and other nearby barriers were removed. However, this upper reach beyond S 126th Street has a cobble streambed that is likely supporting macroinvertebrates, a food source for fish downstream of the barriers. Figure B -3 shows the inventory of fish - blockages in the creek systems of Tukwila, including Riverton Creek. Attachment A to this Appendix B contains a detailed inventory of barriers to fish passage within the City of Tukwila. B -12 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION Southeast Central Business District (CBD) Basin Drainage Characterization The Southeast CBD drainage basin shown in Figure B -1 is formed by the Green River on the west and the BNSF railroad track to the east. Most of the basin contains developed commercial areas along the West Valley Highway corridor with some wetland areas located along the east side of the basin adjacent to the BNSF railroad track. The Southeast CBD basin has multiple outlets. Drainage from the West Valley Highway and the area in the west side of the drainage basin drain directly into the Green River through numerous storm drainage outfalls. The area east of the West Valley Highway drains into the wetlands on the east side of the basin. Overflow from these wetlands drains east into the City of Renton through culverts under the BNSF railroad tracks. City of Tukwila surface water pump station #16 is located within this CBD drainage basin (Figure B -1). Water Quality Characterization The use -based classification for the Southeast CBD basin is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. No water quality data is available for this drainage basin. Fish Habitat Characterization Apart from along the mainstem Green River, which is described in an earlier section of this Appendix, no fish habitat was identified in this basin. Southgate Creek Basin Drainage Characterization The Southgate Creek basin is located in the northwest region of Tukwila, south of Riverton Creek (Figure B -1). Most of the basin is located in the City of Tukwila with the remaining portion (approximately 11 percent) located in the City of SeaTac. Commercial and residential developments are located on the steep -sided slopes in the west portion of the basin (west of Tukwila International Boulevard) and lowlands in the central portion of the basin (between Tukwila International Boulevard and 42nd and 43rd Avenue S). The east portion of the basin, also located in the lowlands, is the least- developed portion of the basin. Private residences are the primary type of development in this area, covering nearly 80 percent of the basin. Water Quality Characterization The Southgate Creek use -based classification is Salmonid Spawning /Rearing and Secondary Contact Recreation, because the drainage discharges to the Duwamish River downstream of the confluence with the Black River. No water quality data is available for this drainage basin. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -13 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Fish Habitat Characterization The East Fork of Southgate Creek begins as a relatively small channel just south of S 137th Street and flows north through a steep ravine, several culverts, and an asphalt -lined ditch before it merges with the west fork. The West Fork begins as three smaller tributaries that collect flow from the hillside just west of 40th Avenue S and merge just upstream of S 133th Street. The West Fork then passes underneath S 133rd Street and 42nd Avenue S through more than 500 feet of culvert and merges with the east fork coming from a ditch along S 132nd Street. From there, the main stem of Southgate Creek extends under SR 599 through about 320 feet of culvert, a fish ladder, and large arch culvert into the Duwamish River downstream of the Black River confluence. Coho salmon are potentially present in Southgate Creek, according to WDFW, and resident trout or and other types of non - anadromous fish are likely present. The fish ladder at the SR 599 culvert likely is a fish barrier to anadromous fish during low stream flows. As in other urbanized streams, development has altered Southgate Creek's riparian buffer and natural channel alignment, resulting in increased channel incision, stream bank erosion, and degraded water quality. Suitable fish habitat is limited to the following: • Rearing habitat in the main stem between SR 599 and S 132nd Street culvert • Rearing habitat in some small sections of the east fork along S 131St Place and S 134th Place • Rearing and some spawning habitat in the recently- restored section of the west fork just upstream of S 133rd Street Bank erosion from the combination of steep gradients and stormwater runoff from urban development have deposited sediments in the lower reach, which have reduced effective culvert conveyance capacities and covered up salmon spawning gravels. The section of the main stem just downstream of the confluence of the West and East Forks is often completely blocked by sediment and debris. During a February 2011 site visit, juvenile salmonids were observed in the section of the east fork along S 131st Place, which are reportedly released into the stream by a nearby homeowner. Fish are unlikely to be present in the West Fork of Southgate Creek upstream of Macadam Way S due to the steep gradient. Some resident fish may use the upper reaches of the east fork within Southgate Park. Figure B -3 shows the inventory of fish - blockages in the creek systems of Tukwila, including Southgate Creek. Attachment A to this Appendix B contains a detailed inventory of barriers to fish passage within the City of Tukwila. Johnson Creek Basin Drainage Characterization The Johnson Creek basin is located to the south of the P17 basin and extends southward to the City of Tukwila boundary with the City of Kent and westward to I -5. Much of the B -14 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX B DRAINAGE, WATER QUALITY, AND FISH HABITAT CHARACTERIZATION Johnson Creek basin was recently annexed into the City of Tukwila (Figure B -1). The approximately 850 -acre basin includes about half of the Tukwila South commercial development site. The basin includes steep hillsides leading up to I -5 as well as Green River floodplain lowlands. In times of high Green River water levels, runoff ponds behind the Green River levees until the river stage drops, allowing discharge by gravity through the flap gate and outfall at the Johnson Creek outlet to the Green River. Water Quality Characterization The Johnson Creek use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. No water quality data is available for this drainage basin. Fish Habitat Characterization The Johnson Creek flap gate and outfall to the Green River, partial blockages to fish passage, were replaced with a fish - passable structure as part of the mitigation for the proximate commercial development. No other barriers to fish passage were identified in Johnson Creek. Figure B -3 shows the inventory of fish - blockages in the creek systems of Tukwila, including Johnson Creek. Attachment A to this Appendix B contains a detailed inventory of barriers to fish passage within the City of Tukwila. The lower reach of Johnson Creek was reconstructed in 2011 as part of mitigation for the commercial development in the area. As the commercial development is completed, an aquatic habitat assessment should be conducted in order to assess conditions post - development and to assess the effectiveness of the mitigation. References Ecology and Environment. 2007. Lower Duwamish Waterway Source Control Action Plan. Ecology Publication No. 07 -09 -003, Lacey, Washington. Entranco, Inc., et al. 1997. Riverton Creek Stormwater Quality Management Plan: Water Quality, Stream Habitat, and Flood Control. Prepared by Entranco Inc., Taylor Associates Inc., and Envirovision Inc. Prepared for the City of Tukwila. November. Herrera Environmental Consultants, Inc. 2001. Gilliam Creek Basin: Stormwater Management Plan. Prepared for the City of Tukwila. March. King County and Washington State Conservation Commission. 2000. Habitat Limiting Factors and Reconnaissance Assessment Report: Green/Duwamish and Central Puget Sound Watersheds. December. King County. 2011. Stream and River Water Quality Monitoring. http:// green. kingcounty .gov /w1r /waterres /streamsdata/ accessed on February 10, 2011. Larson. 2011. Personal communication (conversation with Ryan Larson, City of Tukwila Public Works Department). Tukwila City Hall, Tukwila, WA. November 30. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX B -15 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN WSDOT. 2007. SR 518 SeaTac Airport to 1 -5/1 -405 Interchange Widening Project: Culvert Mitigation. February. WDFW. 2010. Fish Passage Barrier Inventory Geodatabase. Accessed via email by Brian Benson, WDFW Habitat Program, on January 14, 2011. Windward Environmental. 2010. Lower Duwamish Waterway Remedial Investigation, Seattle, Washington. B -16 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX ATTACHMENT A Fish - blocking Culvert Inventory TECHNICAL MEMORANDUM CH2MHILL, City of Tukwila Fish Passage Barrier Inventory PREPARED FOR: Ryan Larson, City of Tukwila Surface Water Management PREPARED BY: Erin Thatcher /CH2M HILL Randy Whitman /CH2M HILL REVIEWED BY: Amy Carlson/ CH2M HILL DATE: November 22, 2011 PROJECT NUMBER: 412954.TT.02 Introduction This memo documents the fish passage barrier inventory developed for the City of Tukwila (the City). The purpose of the inventory is to provide a baseline of information that will inform future planning efforts and prioritization of capital and programmatic improvements related to fish - bearing streams within the City's jurisdiction. The inventory includes information gathered from the Washington Department of Fish and Wildlife (WDFW) and a windshield survey completed for the City's 2010 Surface Water Comprehensive Plan. The inventory encompasses the four main fish - bearing streams in the City's jurisdiction: Riverton Creek, Southgate Creek, Gilliam Creek, and Johnson Creek. Each of these streams is identified by WDFW as having the potential to support anadromous fish such as coho salmon (Oncorhynchus kisutch). The WDFW fish passage barrier inventory does not currently identify any barriers on the Duwamish River, and the inventory in this memo does not include the Duwamish River. Determining a culvert's (or other structure's) fish passability according to accepted standards involves a detailed engineering analysis (developed by WDFW) beyond the scope of this effort. For the areas that were not covered by WDFW's existing inventory, a best professional judgment of fish passability was made based on information gathered during the windshield survey. The windshield survey was conducted by a CH2M HILL professional fish biologist and an assistant scientist on February 3 and 4, 2011. Method The steps outlined below summarize the method used to develop the fish passage barrier inventory. 1. Gathered existing information and data from WDFW and other sources (listed below) 2. Created a basemap from the existing data, which included roads, stream channels, WDFW- mapped fish presence, WDFW fish barrier inventory, and City- mapped culverts WBG031611103411SEA1 APPXB _FISH_BARRIERS_MEMO_V2_20111111 1 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL CITY OF TUKWILA FISH PASSAGE BARRIER INVENTORY 3. Identified information gaps from the basemap and existing information (e.g., road crossings without a corresponding WDFW fish passage feature) 4. Completed a windshield survey to fill information gaps, determine fish passability of areas uncovered by WDFW's inventory, and assess general aquatic habitat conditions for the 2010 Surface Water Comprehensive Plan 5. Created a new GIS database file of fish passage barriers incorporating WDFW's existing inventory and new information from the windshield survey Sources of existing information on fish passage and habitat that were evaluated during development of the inventory include: • WDFW Fish Passage Barrier Inventory GIS data (WDFW, 2010) • WSDOT Fish Passage Inventory (WSDOT and WDFW, 2010) • WRIA 9 Limiting Factors Analysis (King County and Washington State Conservation Commission, 2000) • Existing knowledge of City of Tukwila staff (Personal communications) • Tukwila's 2003 Comprehensive Surface Water Management Plan (CH2M HILL, 2003) • Gilliam Creek Basin Plan (Herrera, 2001) • Riverton Creek Basin Plan (Entranc, 1997) • Fostoria (Southgate) Creek Basin Plan (Herrera, 1996) • Johnson Creek Restoration Plan (Cedarock Consultants, 2010) • Tukwila South Project Final Environmental Impact Statement • King County's WRIA 9 Salmon Habitat Plan • Wild Fish Conservancy (formerly Washington Trout) website: http://wildfishconservancy.org/ Of these, the primary sources of information used to create the inventory are the WDFW fish passage barrier inventory and the February 2011 windshield survey. The WDFW fish passage barrier data are collected under the auspices of the Fish Passage Barrier and Surface Water Diversion Screening Assessment and Prioritization Manual (WDFW, 2009). The data do not represent a complete and comprehensive inventory of all waters. Numerous fish passage inventories are being conducted across the state and the data set is updated when new information becomes available. Table 1 summarizes key information from the fish passage inventory GIS database. Road crossings and other fish passage features were not always covered by the WDFW inventory or accessible in the field during the windshield survey. Remaining information gaps are noted by the entry "Unknown" both in the GIS database and in Table 1. Figures 1, 2, 3, 4, and 5 on the following pages show the fish passage barrier inventory for Riverton Creek, Southgate Creek, Lower Gilliam Creek, Upper Gilliam Creek, and Johnson Creek, respectively. Attachment A to this memo provides photographs of the fish passage features observed during the February 2011 windshield survey; not all fish passage features were accessible for photographs. WBG031611103411SEA1 APPXB _FISH_BARRIERS_MEMO_V2_20111111 2 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL CITY OF TUKWILA FISH PASSAGE BARRIER INVENTORY TABLE 1 Tukwila Fish Barrier Inventory Barrier Survey Problems Fish Passage IDa Locationb Feature Type Status Date` Owner Type Data Source (CH2M HILL Added) Culvert IDe Riverton Creek 14673 W (upstream) of SR 99 Culvert None 10/2/2003 City WDFW None 14674 SR 99 Culvert Total 10/2/2003 State WDFW Unknown 14675 126th St Culvert Partial 10/2/2003 City WDFW Unknown 1077 14676 S 126th St Culvert Partial 10/2/2003 Private WDFW Unknown 14677 S 126th St Culvert None 10/2/2003 Private WDFW None 19812 N of S 128th St Dam Total 10/2/2003 Private WDFW Unknown 885 21065 34th Ave S Culvert Potential 10/2/2003 City WDFW Unknown 1460 20534 W of 35th Ave S Artificial waterfall Total 7/8/2003 Private WDFW Gradient n/a 20533 W of 35th Ave S Artificial waterfall Total 7/8/2003 Private WDFW Gradient n/a 50002 Unnamed road ( Outfall to Duwamish River) Culvert Partial n/a City CH2M HILL Flap gate 50003 SR 599 Culvert Potential n/a State CH2M HILL Unknown 50005 Unnamed road (Adjacent to E Marginal Way just S of SR 599) Culvert Partial 2/4/2011 City CH2M HILL Length; others possible 50006 S 126th St Culvert None 2/4/2011 City CH2M HILL None 994 50007 S 128th St Culvert None 2/4/2011 City CH2M HILL None 1803 50008 S 128th St Culvert Total 2/4/2011 City CH2M HILL Gradient; length, others possible 1606 50004 Unnamed road (Just upstream of SR 599) Culvert Potential n/a Unknown CH2M HILL Unknown 50009 S 120th PI (Restored stream length in industrial park) Culvert None 2/4/2011 City CH2M HILL None 872 50010 Unnamed road (Restored stream length in industrial park) Culvert None 2/4/2011 City CH2M HILL None 920 50011 Unnamed (Restored stream length in industrial park) Culvert None 2/4/2011 City CH2M HILL None 925 50022 W of Group Health building (main stream reach) Log jam Partial 2/4/2011 Unknown CH2M HILL Insufficient pool downstream of log jam obstacle n/a 50023 S 128th St Artificial waterfall Total 2/4/2011 Private CH2M HILL Gradient n/a Southgate Creek 50012 Unnamed road (Outfall to Duwamish River) Culvert None 2/3/2011 City CH2M HILL None 1487 50013 Interurban Ave S Culvert Partial 2/3/2011 City CH2M HILL Fish ladder at low flows 1932 50014 SR 599 Culvert Potential n/a State CH2M HILL Unknown 1932 50015 S 132nd St Culvert Partial 2/3/2011 City CH2M HILL Sediment blockage 1420 50016 44th PI S Culvert None 2/3/2011 City CH2M HILL None 1035 50017 S 132nd St Culvert None 2/3/2011 City CH2M HILL None 1591 50018 S 133rd St Culvert None 2/3/2011 City CH2M HILL None 2086 50019 Commercial lot just S of S 133rd St Culvert Total 2/3/2011 Unknown CH2M HILL Perched; no flow 2225 WBG031611103411SEA1 APPXB _ FISH _BARRIERS _MEMO _V2_20111111 3 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL TABLE 1 Tukwila Fish Barrier Inventory Barrier Survey Problems Fish Passage IDa Locationb Feature Type Status Date` Owner Type Data Source (CH2M HILL Added) Culvert IDe 50020 Unnamed road (driveway in restored stream length just N of S 133rd St) Culvert 50021 S 133rd St/E Marginal Way Culvert None 2/3/2011 Unknown CH2M HILL None Total 2/3/2011 City CH2M HILL Gradient; others possible 1877 50025 S 134th PI Culvert None 2/3/2011 City CH2M HILL None 953 50026 S 134th PI Culvert None 2/3/2011 City CH2M HILL None 988 50027 S 134th PI Culvert None 2/3/2011 City CH2M HILL None 2068 50028 S 134th PI Culvert None 2/3/2011 City CH2M HILL None 1285 50029 S 134th PI Culvert None 2/3/2011 City CH2M HILL None 1370 50030 S 134th PI Culvert None 2/3/2011 City CH2M HILL None 1203 Gilliam Creek 14611 1 -405; NB on -ramp Culvert Partial 12/11/2007 State WDFW Unknown 14737 1 -5; NB to 1 -405 Culvert Total 9/9/2009 State WDFW Unknown 40359 SR 518 Culvert Total 9/15/2009 State WDFW Unknown 40863 61st Ave SE Culvert None 3/1/2007 City WDFW Unknown 40864 1 -405 NB shoulder Culvert Partial 9/8/2009 State WDFW High discharge during high flows; length 44984 Southcenter Blvd Culvert Total 9/9/2009 City WDFW Unknown 44985 51st Ave S Bridge None 9/9/2009 City WDFW Unknown 44986 Southcenter Blvd 44989 Southcenter Blvd 44990 42nd Ave S 44994 Tukwila Pkwy 17539 SR 518 40532 SR 518 Culvert Total 9/9/2009 City WDFW Unknown Culvert Total 9/9/2009 City WDFW Unknown Culvert n/a Total 9/10/2009 City WDFW Unknown 3086 Culvert Partial 9/8/2009 City WDFW Flap gate Culvert N/A 9/13/2005 State WDFW Unknown Culvert Total 9/16/2009 State WDFW Unknown 40861 1 -5; NB off-ramp Culvert Total 2/27/2007 State WDFW Unknown 44979 39th Ln S (Upper Gilliam) Culvert Total 9/15/2009 Unknown WDFW Unknown 44981 S 154th St (Upper Gilliam) Culvert Total 9/15/2009 Private WDFW Unknown 44983 SR 518 (Upper Gilliam) Culvert Partial 9/16/2009 Unknown WDFW Unknown 44991 W of 42nd Ave S (Upper Gilliam) Dam Total 9/10/2009 Private WDFW Gradient n/a 44992 S 150th St (Upper Gilliam) Culvert Partial 9/16/2009 City WDFW Unknown 44993 N of S 150th St (Upper Gilliam) Culvert Total 9/17/2009 Unknown WDFW Unknown 45078 Gilliam Regional Detention Facility Dam Partial 9/10/2009 City WDFW Unknown n/a at SR 518 /Southcenter Blvd (Upper Gilliam) 45118 SR 518 (Upper Gilliam) Abandoned None 9/16/2009 Unknown WDFW Unknown 50031 S 152nd St (Upper Gilliam) Culvert Potential n/a City CH2M HILL Unknown WBG031611103411SEAVAPPXB _ FISH _BARRIERS _MEMO _V2_20111111 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL 4 TABLE 1 Tukwila Fish Barrier Inventory Barrier Survey Problemd Fish Passage IDa Locationb Feature Type Status Date` Owner Type Data Source (CH2M HILL Added) Culvert IDe Johnson Creek 50000 Outfall to Green River Flood gate Partial n/a City CH2M HILL Assumes newly installed flood gate is fish - passable at most flows. 50001 S 204th St Culvert Potential 2/3/2011 Unknown CH2M HILL Unknown 50024 Outfall to Green River Culvert None n/a City CH2M HILL Assumes newly installed culvert is fish - passable. NOTES: a The Fish Passage ID number is a unique identifier number that corresponds to the "Fish_Passage_ID" attribute within the GIS database and figures. The number was either assigned by WDFW (where WDFW is the data source for the fish passage feature) or by CH2M HILL (where CH2M HILL was the data source for the fish passage feature). bThe Location indicates the road crossing or other location description based on the nearest road or major landmark. ° The Survey Date indicates either 1) the date that WDFW surveyed the fish passage feature or 2) CH2M HILL visited the feature during windshield survey. If no date is listed, the feature has not yet been assessed in the field. d The Problem listed here corresponds to the "CH_Problem" attribute within the GIS database, and indicates the specific cause of fish impassability. Some information was not available from the WDFW inventory or windshield survey. e The Culvert ID corresponds to the culvert feature ID number in the City's GIS database. WBG031611103411 SEAWPPXB_FIS H_BARRI ERS_MEMO_V2_20111111 5 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL References Cedarock Consultants, Inc. 2010. Tukwila South Project Fisheries Mitigation Plan. June. CH2M HILL. 2003. City of Tukwila Comprehensive Surface Water Management Plan. Prepared by CH2M HILL, Inc. Prepared for the City of Tukwila. November. Entranco, Inc., et al. 1997. Riverton Creek Stormwater Quality Management Plan: Water Quality, Stream Habitat, and Flood Control. Prepared by Entranco Inc., Taylor Associates Inc., and Envirovision Inc. Prepared for the City of Tukwila. November. Herrera Environmental Consultants, Inc. 1996. Fostoria Basin: Stormwater Quality Management Plan. Prepared for the City of Tukwila. March. Herrera Environmental Consultants, Inc. 2001. Gilliam Creek Basin: Stormwater Management Plan. Prepared for the City of Tukwila. March. Howat. 2010. Personal communication (conversation with John Howat, City of Tukwila Public Works Department). Tukwila City Hall, Tukwila, WA. November 30. King County and Washington State Conservation Commission. 2000. Habitat Limiting Factors and Reconnaissance Assessment Report: Green/Duwamish and Central Puget Sound Watersheds. December. Washington Department of Fish and Wildlife (WDFW). 2009. Fish Passage and Surface Water Diversion Screening Assessment and Prioritization Manual. Washington Department of Fish and Wildlife. Olympia, Washington. WDFW. 2010. Fish Passage Barrier Inventory Geodatabase. Accessed via email by Brian Benson, WDFW Habitat Program, on January 14, 2011. Whiting. 2011. Personal communication (email correspondence with Sandra Whiting, City of Tukwila Department of Community Development). CH2M HILL, Bellevue, WA. January 27. WSDOT and WDFW. 2010. Progress Performance Report for WSDOT Fish Passage Barrier Inventory. May. WSDOT. 2007. SR 518 SeaTac Airport to I -5/1 -405 Interchange Widening Project: Culvert Mitigation. February. WBG031611103411SEA1APPXB _FISH_BARRIERS_MEMO_V2_20111111 6 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL Attachment A Photographs This information is intended for planning purposes only. Additional information would be required to support design and construction. Figure 1. Riverton Creek Fish Passage Barrier Inventory N 0 250 500 1,000 1,500 CC■Feet Legend Fish Passage Features Culverts Fish Passage Features - Other Barrier Status Barrier Status O N/A A Partial O None A Total O Partial Stream O Potential I=1 Drainage Basins • Total D Tukwila Boundary Path: \ \simba\ prof\ TukwilaWACityOfl412954SWCompPI \GIS\ Layout\ Erin \9.3\ TukwilaFishPassageMapBook _20111110.mxd ethatche 11/14/2011 8:25:39 AM 50011 50022*J 20533,4V' 2053z1- =r 14677 _ 1467k6 -L.. 14675 50008 -50000 50013 Gaye Survey limit S 130th St Survey limit Survey limit 501321 S 136th St S 137th St 5136th S Survey limit S 139th St' S 140th St co ;: ST-141st St' Q F ,5 142ndSt 1r;r At∎ - '1 H471 . S 144tt St This information is intended for planning purposes only. Additional information would be required to support design and construction. Figure 2. Southgate Creek Fish Passage Barrier Inventory N 0 250 500 1,000 1,500 ICC■Feet Legend Fish Passage Features Culverts Fish Passage Features - Other Barrier Status Barrier Status • N/A A Partial • None A Total O Partial Stream O Potential I=1 Drainage Basins • Total =I Tukwila Boundary Path: \ \simba\ prof\ TukwilaWACityOt \412954SWCompPI \GIS\ Layout\ Erin \9.3\ TukwilaFishPassageMapBook _20111110.mxd ethatche 11/14/2011 8:25:39 AM This information is intended for planning purposes only. Additional information would be required to support design and construction. Figure 3. Lower Gilliam Creek Fish Passage Barrier Inventory N 0 250 500 1,000 1,500 CC■Feet Legend Fish Passage Features Culverts Fish Passage Features - Other Barrier Status Barrier Status O N/A A Partial O None A Total O Partial Stream O Potential I=1 Drainage Basins • Total =I Tukwila Boundary Path: \ \simba\ prof\ TukwilaWACityOfl412954SWCompPI \GIS\ Layout\ Erin \9.3\ TukwilaFishPassageMapBook _20111110.mxd ethatche 11/14/2011 8:25:39 AM IS 146th St S 148th St / -993 r 44911•%%y' S 150th St 4+S 150th St' S 152nd St CO r 50031 Q i a ,- s.. �s .. 4498 5078 4z ' ur 1 44986, • ob. gets, ' `,'� 44985 z .` n ,.. — 7539 S 152nd St S 158th St S 16_ th_St� S 164th St" This information is intended for planning purposes only. Additional information would be required to support design and construction. Figure 4. Upper Gilliam Creek Fish Passage Barrier Inventory N 0 250 500 1,000 1,500 CC■Feet Legend Fish Passage Features Culverts Fish Passage Features - Other Barrier Status Barrier Status O N/A A Partial • None A Total O Partial Stream O Potential I=1 Drainage Basins • Total =I Tukwila Boundary Path: \ \simba\ prof\ TukwilaWACityOfl412954SWCompPI \GIS\ Layout\ Erin \9.3\ TukwilaFishPassageMapBook _20111110.mxd ethatche 11/14/2011 8:25:39 AM ST,188th St' This information is intended for planning purposes only. Additional information would be required to support design and construction. Figure 5. Johnson Creek Fish Passage Barrier Inventory N 0 250 500 1,000 1,500 CC■Feet Legend Fish Passage Features Culverts Fish Passage Features - Other Barrier Status Barrier Status O N/A A Partial O None A Total O Partial Stream O Potential I=1 Drainage Basins • Total =I Tukwila Boundary Path: \ \simba\ prof\ TukwilaWACityOfl412954SWCompPI \GIS\ Layout\ Erin \9.3\ TukwilaFishPassageMapBook _20111110.mxd ethatche 11/14/2011 8:25:39 AM ATTACHMENT A: PHOTOGRAPHS Photo 1. East Fork Riverton Creek: view downstream from the outlet of the 2, 000 -foot long pipe along East Marginal Way S (fish passage ID 50005, partial barrier). (Date: 2/4/2011) Photo 3. East Fork Riverton Creek: view of the privately -owned waterfall (fish passage ID 50007, total barrier) just upstream of the S 128th Street culvert (fish passage ID 50023, non - barrier). (Date: 2/4/2011) Photo 2. East Fork Riverton Creek: view upstream from the culvert under S 126th Street (fish passage ID 50006, non - barrier). (Date: 2/4/2011) Photo 4. West Fork Riverton Creek: view of log jam (fish passage ID 50022, partial barrier) in restored channel area. (Date: 2/4/2011) WBG031611103411SEAWTTA _PHOTOS- FISHPASSAGEINVENTORY TUKWILASWCP V2 A -1 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL ATTACHMENT A: PHOTOGRAPHS Photo 5. West Fork Riverton Creek: view of the waterfall just Photo 6. West Fork Riverton Creek: view upstream from the upstream of the restored channel area (fish passage ID 20533, top of the large waterfall in Photo 5, toward fish passage ID total barrier). (Date: 2/4/2011) 20534 (total barrier).(Date: 2/4/2011) Photo 7. Southgate Creek: view of the outlet of the culvert under Interurban Avenue S (fish passage ID 50013, partial barrier). The fish ladder just inside the culvert is considered a partial fish passage barrier because low flows did not appear sufficient to allow fish to jump over the weirs. (Date: 2/3/2011) Photo 9. Southgate Creek: view of pipe outlet into the wetland that conveys the main branch (fish passage ID 50015, partial barrier) just upstream of SR 599. (Date: 2/3/2011) Photo 8. Southgate Creek: view of inlet to City -owned culvert under S 132nd Street (fish passage ID 50015, partial barrier). There was no flow through the culvert due to sediment blockage at the time this photo was taken. (Date: 2/3/2011) Photo 10. East Fork Southgate Creek: view of the east end of the culvert under 44th Place S (fish passage ID 50016, non - barrier). Flow from the west fork was diverting into a pipe at S 133rd Street, instead of passing into the main channel, due to channel gradient and sediment blockage. (Date: 2/3/2011) WBG031611103411SEAWTTA _PHOTOS- FISHPASSAGEINVENTORY TUKWILASWCP V2 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL A -2 ATTACHMENT A: PHOTOGRAPHS Photo 11. West Fork Southgate Creek: view of the inlet to the long culvert under S 133rd Street (fish passage ID 50021, total barrier). The steep gradient as well as the structures shown here and in Photo 12 combine to act as a total fish passage barrier. (Date: 2/3/2011) Photo 13. Gilliam Creek: view of the log at the inlet to WSDOT- owned culvert at the northbound 1 -405 on -ramp (fish passage ID 14611, partial barrier). (Date: 2/3/2011) Photo 12. West Fork Southgate Creek: view of weir at the inlet to the long culvert under S 133rd Street (fish passage ID 50021, total barrier). The weir's height exceeds the fish jumping criteria by 0.10 foot, and the culvert just downstream was considered too steep for fish. Habitat just upstream provides some suitable spawning gravel, possibly for resident trout. (Date: 2/3/2011) Photo 14. Gilliam Creek: view of the outlet of the WSDOT- owned culvert under the south shoulder of 1 -405 (fish passage ID 40864, partial barrier). This 1,100 -foot long culvert is identified as a partial fish passage barrier likely because of high discharge during high stream flows due to its length. (Date: 2/3/2011) WBG031611103411SEAWTTA _PHOTOS- FISHPASSAGEINVENTORY TUKWILASWCP V2 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL A -3 ATTACHMENT A: PHOTOGRAPHS Photo 15. Upper Gilliam Creek: view downstream from the 42nd Avenue S culvert (fish passage ID 44990, total barrier). A view of the actual culvert was not possible due to physical constraints. (Date: 2/4/2011) Photo 16. Gilliam Creek: view of the presumed outlet of the culvert under the 1 -5/1 -405 interchange (fish passage ID 14737, total barrier). It was not clear from the available mapping whether this culvert conveys flow from upper Gilliam Creek, or from stormwater detention managed by WSDOT. (Date: 2/3/2011). Photo 17. Upper Gilliam Creek: view upstream from the City - owned culvert under 42nd Ave S, toward the dam feature located on privately -owned property (fish passage ID 44991, total barrier). (Date: 2/4/2011) WBG031611103411SEAWTTA _PHOTOS- FISHPASSAGEINVENTORY TUKWILASWCP V2 A -4 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL ATTACHMENT A: PHOTOGRAPHS Photo 18. Upper Gilliam Creek: view of the Gilliam Creek RDF structure (fish passage ID 45078, partial barrier). This feature was identified as a partial barrier by WDFW, but appeared to be a total barrier during the windshield survey. (Date: 2/4/11) Photo 20. Johnson Creek: view upstream of the old inlet to the outfall to the Green River (fish passage ID 50000, partial barrier). The flap gate and outfall were replaced with a fish - passable structure (see Photo 21). (Date: 2/3/2011) Photo 19. Upper Gilliam Creek: view downstream from outlet of the culvert underneath Southcenter Boulevard (fish passage ID 44989, total barrier). In addition to the culvert identified by WDFW as a total barrier, the flow appeared too low for adult fish through this length. (Date: 2/4/11) Photo 21. Newly restored section of the main Johnson Creek: reach, looking upstream of the inlet to the outfall to the Green River (fish passage ID 50000, partial barrier). The culvert and flood gate were replaced with a fish - passable structure (passable under most flow conditions) under the mitigation for the adjacent Tukwila South project. (Date: Fall 2011) WBG031611103411SEAWTTA _PHOTOS- FISHPASSAGEINVENTORY TUKWILASWCP V2 COPYRIGHT 2011 BY CH2M HILL, INC. • COMPANY CONFIDENTIAL A -5 APPENDIX C Surface Water Regulations and Policies (SUPPORTING INFORMATION FOR PLAN SECTION 3) APPENDIX C Surface Water Regulations and Policies This Appendix C contains the detailed assessment of regulations applicable to the City of Tukwila's surface water program. The information presented here is summarized in Section 3 of this Surface Water Comprehensive Plan. Applicable Surface Water Regulations Regulatory changes have occurred since preparation of the 2003 City of Tukwila Comprehensive Surface Water Management Plan. The changes most significant for Tukwila are with National Pollutant Discharge Elimination System (NPDES) Phase II permit. Regulations currently applicable to the City of Tukwila's surface water management program are shown in Table C -1. (Note that flood protection and flooding as a result of Green or Duwamish River flooding are outside the scope of this Plan.) TABLE C -1 Summary of Applicable Surface Water Regulations Regulation or Program (organized by category) Tukwila Surface Water Management Program Areas Surface Water Water Quality Aquatic Habitat Surface Water Management Surface Water Management Ordinance, Tukwila Municipal Code 14.30, and resultant surface water planning Surface Water Design Manual Capital projects to address drainage problems; many needed projects await funding Adoption of the 2009 King County Surface Water Design Manual Capital projects to address water quality concerns; projects await funding Adoption of the 2009 King County Surface Water Design Manual Capital projects to address aquatic habitat concerns or opportunistically protect /restore habitat; projects await funding Not Applicable. Water Quality State surface water quality standards Section 303(d) list Not Applicable Not Applicable. Several water bodies do not meet standards. Anti- degradation standard difficult to achieve. Need to identify pollution sources and implement prevention programs. 303(d) impaired listings will require development of TMDLs; Tukwila would be one of several jurisdictions involved Degraded water quality impacts aquatic habitat, lessening benefits of habitat protection or restoration efforts Not Applicable. WBG031611103411 SEAITU KW I LASURFACEWATERCOM PPLAN_FINAL_V2. DOCX C -1 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE C -1 Summary of Applicable Surface Water Regulations Regulation or Program Tukwila Surface Water Management Program Areas (organized by category) Surface Water Water Quality Aquatic Habitat Total Maximum Daily Not Applicable. Not yet applicable to Not Applicable. Loads (TMDLs) Tukwila (see above); however, studies and implementation may be initiated as a part of TMDL development NPDES Phase II See Table C -2 See Table C -2 Not Applicable. permit Habitat Endangered Species Protection Act State Salmon Recovery Planning Act Growth Management Act City regulations and policies generally support compliance with the ESA and encourage salmon recovery. Not Applicable. Adopted Stormwater Management Manual for Western Washington City demonstrates understanding of environmental baseline conditions (see basin pans and other documents). Not Applicable. Adopted Stormwater Management Manual for Western Washington Update the SEPA ESA screening checklist to include Coastal -Puget Sound bull trout and Puget Sound Steelhead. City has implemented capital improvement projects that restore fish habitat for ESA - listed species but should implement more projects. Not Applicable. As was done in 2003 as part of that comprehensive planning effort, this 2010 Plan contains an evaluation, or gap analysis, of Tukwila's surface water management program against all relevant surface water management regulations. While Table C -1 contains a high -level assessment of all applicable surface water regulations, Table C -2 contains a more detailed gap analysis of Tukwila's surface water management program against the requirements of the NPDES Phase II permit. Improvements to Tukwila's surface water management program recommended as a result of the gap analyses are outlined later in this Appendix. NPDES Municipal Stormwater Phase II Permit Table C -2 contains a detailed gap analysis of Tukwila's surface water management program against the NPDES Phase II permit. Since preparation of Tukwila's 2003 Surface Water Management Plan, the Phase II NPDES permits have changed and Tukwila has responded by expanding their surface water management program to meet those requirements. The gap analysis included in this Plan is intended to enhance and document Tukwila's previous investments in NPDES Phase II compliance, including an extensive Surface Water Management Program development as well as preparation and submittal of annual reports. C -2 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX C SURFACE REGULATIONS AND POLICIES As a result of the gap analysis, this Plan contains recommendations for program improvements that need to be implemented to achieve compliance. The outlined recommended program improvements listed later in this Appendix reflect Tukwila's significant investment in NPDES Phase II compliance activities since preparation of the 2003 Surface Water Comprehensive Plan. Environmental Species Act (ESA) The Environmental Species Act (ESA) of 1973 provided broad protection for listed threatened and endangered species and their designated critical habitat. As of June of 2011, the salmon and trout listings applicable for Puget Sound are • Chinook salmon (Threatened) • Coho Salmon (Species of Concern) • Steelhead (Threatened; Critical Habitat Designation) • Bull trout (Threatened) The listings for bull trout and coho salmon have occurred since development of the 2003 Surface Water Comprehensive Plan. The listing for Puget Sound cutthroat trout was determined to be not warranted, though listings are in effect for other geographic areas. The ESA prohibits a "take" of a listed species by any person subject to the jurisdiction of the United States, which applies to both public and private lands and activities. Both a person whose actions harm or harass a protected species and a government entity that authorizes that person's actions can violate the ESA prohibitions. Thus, the City of Tukwila is responsible for implementation of plans and policies that support the ESA prohibitions. Coho salmon are thought to be present in Gilliam Creek, Southgate Creek, and Riverton Creek within the boundaries of the City of Tukwila. Chinook are thought to be present in both Riverton Creek and Gilliam Creek. These streams historically did not provide extensive habitat for Chinook salmon because Chinook tend to use larger streams for spawning and rearing. Generally, City regulations and policies support compliance with ESA and encourage salmon recovery. With this recent listing of coho as a species of concern, areas within these creeks used by coho for rearing, foraging, and migration should be protected and /or enhanced. In addition, there may be opportunities for improvements to road maintenance practices, stormwater treatment, and watershed management that would improve conditions for coho in Gilliam, Southgate, and Riverton Creeks. The City should update the State Environmental Policy Act (SEPA) ESA screening checklist to include Coastal -Puget Sound bull trout (listed as threatened) as Puget Sound steelhead (listed as threatened with a critical habitat designation). WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX C -3 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN This page intentionally left blank. C -4 WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX C SURFACE REGULATIONS AND POLICIES TABLE C -2 NPDES Phase II Requirements and Corresponding City of Tukwila Regulations, Plans, and Programs NPDES Phase II Requirements (per Western Washington Phase II Municipal Stormwater Permit, effective through July 31, 2013) Minimum Performance Measures Associated with NPDES Phase II Requirements Required Date Applicable City Regulation or Program Additional Activities Recommended to Address Requirement 2013 Surface Water Comprehensive Plan Recommendation(s) S5.A2 Implement a Stormwater Management Program Each Permittee must prepare a Stormwater Management Program (SWMP) that describes the activities being carried out to fulfill the requirements of Section S5.C5. S5.C1. Public Education and Outreach Education programs aimed at residents, businesses, industries, engineer, developers, elected officials and city staff to increase knowledge of Best Management Practices (BMPs) and reduce or eliminate practices that cause or contribute to adverse stormwater impacts. The SWMP shall be organized according to the five elements listed in Section S5.C5. An updated SWMP is to be submitted to the Washington Department of Ecology (Ecology) on an annual basis. a) Implement or participate in an education and outreach program targeting the following audiences: i. General Public General impacts of stormwater flows into surface waters Impacts from impervious surfaces Source control BMPs and environmental stewardship actions and opportunities in the areas of pet waste, vehicle maintenance, landscaping, and buffer ii. General public, businesses, including home -based and mobile businesses BMPs for use and storage of automotive chemicals, hazardous cleaning supplies, carwash soaps, and other hazardous materials Impacts of illicit discharges and how to report them iii. Homeowners, landscapers and property managers Yard care techniques protective of water quality BMPs for use and storage of pesticides and fertilizers BMPs for carpet cleaning and auto repair and maintenance Low impact development (LID) techniques, including site design, pervious paving, retention of forests and mature trees Stormwater pond maintenance iv. Engineers, contractors, developers, review staff, and land use planners Technical standards for stormwater site and erosion control plans LID techniques, including site design, pervious paving, retention of forests, and mature trees Stormwater treatment and flow control BMPs b) Implement or participate in an effort to measure understanding and adoption of the targeted behaviors among the targeted audiences. The resulting measurements shall be used to direct education and outreach resources most effectively, as well as to evaluate changes in adoption of the targeted behaviors. c) Track and maintain records of public education and outreach activities. 8/15/2011; Updates due March 31 annually The City prepares annual SWMP updates. 2/16/2009 Educational materials provided to the public include: i. General Public water course signs catch basin labeling City newsletter articles published several times per year hazardous waste directory Ecology pamphlet on 5 Steps To Natural Yard Care ii. General public, businesses, including home -based and mobile businesses spill kit program disposing of hazardous waste information card Ecology pamphlet on reporting spills Sudsafe carwash program iii. Homeowners, landscapers and property managers Puget Sound Shoreline Guidebook Pet Waste brochure iv. Engineers, contractors, developers, review staff, and land use planners Environmental Protection Agency (EPA) information sheet on oil /water separators City Infrastructure Design and Construction Standards 2/16/2009 In January 2010, a survey was mailed to 1,000 Tukwila residents for the purpose of measuring the understanding of practices that impact the stormwater system. Such a survey will be performed annually in the future. Results to be posted on website. 2/16/2009 Public education activities have been tracked since 2008. None Increase opportunities for public involvement in environmental stewardship activities; reach out to children, students, adults, and visitors. None None N/A Education (see Section 7) Education (see Section 7) N/A WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX C -5 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE C -2 NPDES Phase II Requirements and Corresponding City of Tukwila Regulations, Plans, and Programs NPDES Phase II Requirements (per Western Washington Phase II Municipal Stormwater Permit, effective through July 31, 2013) Minimum Performance Measures Associated with NPDES Phase II Requirements Required Date Applicable City Regulation or Program Additional Activities Recommended to Address Requirement 2013 Surface Water Comprehensive Plan Recommendation(s) S5.C2. Public Involvement and Participation Ongoing opportunities for public involvement through advisory councils, watershed committees, etc. S5.C3. Illicit Discharge Detection and Elimination Ongoing program to detect, remove, and prevent illicit connections, discharges, and improper disposal, including spills, into the municipal separate storm sewer system (MS4). Full implementation of an illicit discharge detection and elimination program must be achieved by 8/15/2011. a) Create opportunities for the public to participate in the decision - making 2/16/2008 process involving the development, implementation, and update of the Permittee's entire SWMP. Each Permittee must develop and implement a process for consideration of public comments on their SWMP. b) Each Permittee must make their SWMP, the annual report required under S9.A, and all other submittals required by this Permit, available to the public, preferably by posting the materials on the Permittee's website. a) A storm sewer system map shall be developed to show storm sewer outfalls and all stormwater BMPs owned by the Permittee. The map shall show tributary conveyances, connections to the storm sewers, drainage areas, and land use. These maps should be periodically updated. b) Develop and implement an ordinance or other regulatory mechanism to effectively prohibit non - stormwater, illegal discharges, and /or dumping into the Permittee's municipal separate storm sewer system. Prohibited discharges include runoff from irrigation, sidewalk washing and dust control, municipal water releases for system testing purposes and swimming pool discharges unless dechlorinated to 0.1 ppm or less. This section also lists 13 categories of allowed non - stormwater discharges. An enforcement strategy must be identified along with escalating enforcement procedures. c) Develop and implement an ongoing program to detect and address non- 8/15/2011 stormwater discharges, spills, illicit connections and illegal dumping into the Permittee's municipal separate storm sewer system. 2/16/2008 2/16/2011 Public involvement is encouraged via the City website, City Council, and Utilities Committee meetings, and City news articles. The SWMP, latest annual report, and an email address for public comment are posted on the City's website: www.ci.tukwila.wa.us/pubwks/npdes.html A consultant has been hired to update the City's GIS maps and develop a program to ensure the storm sewer map is kept current. Areas 1 through 5 have been previously mapped. Area 6 (of a total of seven areas) is currently being mapped. Mapping is expected to be completed in the spring of 2011. 9/15/2009 A new City ordinance, TMC 14.31 Illicit Discharge Detection and Elimination, was adopted in March 2010. i. and ii. Locate priority areas likely to have illicit discharges; Conduct field 8/15/2011 assessment activities, including visual inspection of priority outfalls (prioritize receiving waters for visual inspection; screen for illicit connections). iii, iv, and v. Identify procedures for characterizing, tracing and removing illicit 8/15/2011 discharges. d) Permittees shall inform public employees, businesses, and the general public of hazards associated with illegal discharges and improper disposal of waste. i. Distribute information to target audiences. ii. Establish hotline for reporting spills and illicit discharges. i. 8/15/2011 ii. 2/16/2009 c) City maintenance staff respond to hazardous material spills and perform basic containment and cleanup functions. Tracking of illicit discharges began in June 2009. Much of the stormwater piping was videotaped in 2009 and questionable connections were investigated. Approximately 25% of the system has been done (as of December 2011). i and ii. Three outfalls, one to the Green River and two to the Duwamish River, have been identified for visual field assessment. iii, iv, and v. Not completed. A hotline phone number (206- 433 -1860) has been added to the City website: www. ci. tukwila.wa.us /pubwks /npdes.html Hold public meeting and public comment period on the SWMP. None Complete the mapping of the City's stormwater system, including newly annexed area (scheduled completion in Summer 2013). Perform inventory of private stormwater facilities. Plan for periodic updating of stormwater system inventory; inventory should include new infrastructure brought on -line since previous update (such as for new and re- development). None c) Complete inspections of the remaining City stormwater system. As needed, complete cleaning of stormwater lines in order to allow inspections to occur. i and ii. Carry out inspections of the individual tributary areas and outfalls. Iii, iv, and v. Identify procedures for characterizing, tracing, and removing illicit discharges Develop and disseminate information to the public. Public Involvement (see Section 7) N/A Inspections and Enforcement and Illicit Detection and Elimination (see Section 7) N/A Inspections and Enforcement and Illicit Detection and Elimination (see Section 7) Inspections and Enforcement and Illicit Detection and Elimination (see Section 7) Inspections and Enforcement and Illicit Detection and Elimination (see Section 7) Education (see Section 7) C -6 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX C SURFACE REGULATIONS AND POLICIES TABLE C -2 NPDES Phase II Requirements and Corresponding City of Tukwila Regulations, Plans, and Programs NPDES Phase II Requirements (per Western Washington Phase II Municipal Stormwater Permit, effective through July 31, 2013) Minimum Performance Measures Associated with NPDES Phase II Requirements Required Date Applicable City Regulation or Program Additional Activities Recommended to Address Requirement 2013 Surface Water Comprehensive Plan Recommendation(s) S5.C4. Controlling Runoff from New Development, Redevelopment and Construction Sites Develop, implement, and enforce a program to reduce pollutants in stormwater runoff to MS4s from new development, redevelopment, and construction site activities. This applies to all sites 1 acre in size or greater, including those projects less than 1 acre that are part of a larger project. e) Adopt and implement procedures for program evaluation and assessment, including the tracking number and type of spills or illicit discharges identified; inspections made; and any feedback received from public education efforts. f) Provide appropriate training for municipal field staff on the identification and reporting of illicit discharges into MS4s. i. Ensure that all municipal field staff responsible for identification and reporting of illicit discharges are trained to conduct these activities. ii. Implement ongoing training of staff. a) The program shall include an ordinance or other enforceable mechanism that addresses the runoff from new development, redevelopment, and construction site projects. The program must meet the requirements of Ecology's 2005 Stormwater Management Manual for Western Washington or an equivalent manual approved by Ecology. The program should allow the use of LID measures. b) The program shall include a permitting process with plan review, inspection and enforcement capability to meet the standards listed for both private and public projects, using qualified personnel. Elements of the permitting process must include: i. Review of all stormwater site plans for development iii, iv. Site inspection prior, during and at the conclusion of construction v. Attain minimum 80% inspection rate and retain inspection records vi. Enforce non - compliance c) The program shall include provisions to ensure adequate long -term operation and maintenance (O &M) of post- construction stormwater facilities and BMPs that are permitted and constructed pursuant to (b) above. Elements include: ii. Establishment of maintenance standards iii, iv. Prescribed schedule for inspections and maintenance: catch basins: by 2/15/2012 treatment and flow control facilities: annually d) The program shall include a procedure for keeping records of inspections and enforcement actions by staff, including inspection reports, warning letters, notices of violations, and other enforcement records. e) The program shall make available copies of the "Notice of Intent for Construction Activity" and /or copies of the "Notice of Intent for Industrial Activity" to representatives of proposed new development and 8/15/2011 i. 9/15/09 ii. 2/16/2010 2/16/2010 2/16/2010 2/16/2010 2/16/2010 2/16/2010 Field staff dealing with illicit discharges were trained in August 2009 and a staff review was conducted in 2010. Ongoing training is provided for street storm /sewer and water department staff. TMC 14.30 — Surface Water Management defines City responsibilities for stormwater management. TMC 14.30.060.2 adopts the 2009 King County Surface Water Design Manual (KCSWDM) as the City's surface water manual. Per Appendix 10 of the NPDES Permit, the KCSWDM is recognized an equivalent manual approved by Ecology. The City's Infrastructure Design and Construction Standards are also implemented. TMC 14.30.080.A4 provides for unlimited City access to stormwater facilities for inspection and enforcement activities. TMC 14.30.130.B allows for LID measures in projects by exception. TMC 14.30.070 specifies a project review process and issuance of a storm drainage permit. TMC 14.30.10 describes enforcement actions available to the City while TMC 14.130 describes penalties the City may assign a violator for each day of non - compliance. TMC 8.45 provides a system of escalating enforcement procedures. i. The City reviews all development stormwater plans iii, iv, v. The City inspects some construction sites for proper stormwater BMPs but inspections are sporadic. vi. The City carries out enforcement measures for sites that are not in compliance. TMC 14.30.080 describes maintenance requirements and responsibilities for stormwater facilities. TMC 14.30.080.6 places responsibility for maintenance of privately owned facilities on the owner. TMC 14.30.080.A2 and B5 identify a schedule for frequency of inspection and elapsed time for required maintenance. Maintenance standards are those found in the KCSWDM. Develop and carry out systematic inspections of construction sites. These documents are readily available and the City inserts them into the Pre - Application Packet for new projects. Develop and implement. None Develop a proactive approach to LID that encourages innovative design to reduce onsite runoff. Consider developing a map that identifies locations in the City with soils that are conducive to LID measures.(see LID requirements anticipated for next permit cycle) Enhance the City inspection program with adequate staffing to reduce noncompliance with BMP requirements and water quality violations. Develop and carry out systematic inspections of construction sites. Expand the City inspection program to ensure maintenance. Increase inspections and expand enforcement efforts. Keep robust database of inspections and enforcement actions. Enhance tracking and reporting function to ensure maintenance is conducted and documented adequately. None Record - Keeping and Annual Reporting (see Section 7) N/A Regulations (see Section 7) Regulations (see Section 7) Maintenance and Operations and Record - keeping (see Section 7) Record - Keeping and Annual Reporting (see Section 7) N/A WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX C -7 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE C -2 NPDES Phase II Requirements and Corresponding City of Tukwila Regulations, Plans, and Programs NPDES Phase II Requirements (per Western Washington Phase II Municipal Stormwater Permit, effective through July 31, 2013) Minimum Performance Measures Associated with NPDES Phase II Requirements Required Date Applicable City Regulation or Program Additional Activities Recommended to Address Requirement 2013 Surface Water Comprehensive Plan Recommendation(s) S5.C5. Pollution Prevention and Operation and Maintenance for Municipal Operations Develop and implement an O &M program for stormwater facilities for municipal operations. redevelopment. Permittees will continue to enforce local ordinances controlling runoff form sites that are also covered by stormwater permits issued by Ecology. f) The Permittee shall ensure that all staff responsible for implementing the 2/16/2010 stormwater program are trained to conduct these activities. Follow -up training shall be provided as needed to address changes in procedures, techniques, or staffing. Permittees shall document and maintain records of the training provided and the staff trained. a) Adopt maintenance standards that are at least as protective as those specified in Ecology's 2005 Stormwater Management Manual for Western Washington, Volume V, Chapter 4. b) Annual inspection of all municipally owned or operated permanent stormwater treatment and flow control facilities with maintenance, as required. Reduced frequency of inspection is allowed if justified by maintenance records. c) Spot checks of permanent treatment and flow control facilities (other than catch basins) after major storm events, defined as greater than the 10 -year, 24 -hour rain event. d) Inspection of all catch basins and inlets owned or operated by the Permittee at least once before the end of the permit term (February 15, 2012). Clean catch basins if the inspection indicates cleaning is needed. Decant water shall be disposed of in accordance with Permit Appendix 6. Street Waste Disposal. There are provisions for the inspection of a representative subset of catch basins. e) Inspect at least 95 percent of all catch basins. f, g) Establish and implement practices to reduce stormwater impacts associated with runoff from streets, parking lots, roads, or highways owned or maintained by the Permittee, and road maintenance activities conducted by the Permittee. Covered activities include: pipe and culvert cleaning ditch maintenance road repair and resurfacing snow and ice control utility installation road shoulder maintenance dust control fertilizer /pesticide application landscape management trash management 2/16/2010 2/16/2010 2/16/2010 2/16/2010 8/19/2011 2/16/2010 The City has conducted staff training in the application of the revised stormwater procedures. None Maintenance standards are those found in the KCSWDM, which Develop maintenance practices that is equivalent to the Ecology manual. are applicable to the City. TMC 14.30.050.D states that the surface water compliance requirements of TMC 14.30 apply to all City departments except for O &M activities of the Department of Parks and Recreation. TMC 14.30.080 identifies the required frequency of inspection and maintenance. The City is carrying out annual inspections of its stormwater facilities and is documenting all maintenance that is carried out. The City maintains a list of problem areas and complaints, using these to target maintenance. The City has committed to carry out spot checks of its stormwater system following major storm events. The City is committed to inspecting all catch basins. The storm conveyance system is inspected and maintained on a 3 -5 year cycle. Vactor waste is currently disposed of in an open field, with the water allowed to percolate and evaporate. None None Continue inspections. Develop a permanent vactor waste treatment facility or reach an agreement to use an existing facility. Complete inspection of all catch basins by 7/16/2011. Develop a program to reduce pollutants in runoff from City property. N/A Maintenance and Operations (see Section 7) N/A N/A Maintenance and Operations (see Section 7) Maintenance and Operations (see Section 7) Maintenance and Operations (see Section 7) C -8 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX C SURFACE REGULATIONS AND POLICIES TABLE C -2 NPDES Phase II Requirements and Corresponding City of Tukwila Regulations, Plans, and Programs NPDES Phase II Requirements (per Western Washington Phase II Municipal Stormwater Permit, effective through July 31, 2013) Minimum Performance Measures Associated with NPDES Phase II Requirements Required Date Applicable City Regulation or Program Additional Activities Recommended to Address Requirement 2013 Surface Water Comprehensive Plan Recommendation(s) S7. Total Maximum Daily Load (TMDL) Requirements For Permittees whose jurisdictions fall within an area covered by TMDL requirements, specific additional stormwater requirements must be met. S8. Monitoring A. Permittees must conduct water sampling only for TMDL compliance and illicit discharges pursuant to S5.C.3. C. Permittees must prepare for future long -term monitoring. S9. Reporting Requirements building exterior maintenance h) Implement an on -going training program for appropriate employees of the 2/16/2010 Permittee whose construction, operations, or maintenance job functions may impact stormwater quality. Provide follow -up training as necessary. City's O &M training program i) Develop and implement a Stormwater Pollution Prevention Plan (SWPPP) 2/16/2010 The City is preparing a SWPPP for the Tukwila Golf Links for all heavy equipment maintenance or storage yards, and material- storage maintenance center (SWPPP needed for each building). facilities owned or operated by the Permittee that are not required to have coverage under the Industrial Stormwater General Permit. j) Keep records of inspections and maintenance /repair activities. Compliance with TMDL requirements B. Applicable only to water bodies listed in Appendix 2 of the Phase 2 NPDES Permit. C.1.a.iv. Tukwila's population is between 10,000 and 75,000 persons. Therefore the City is required to identify two outfalls where stormwater sampling can be conducted. C.1.b. Select two suitable monitoring objectives that relate to the effectiveness of BMPs or the achievement of an environmental outcome such as a water quality goal. C.2. Permittees within a single Water Resource Inventory Area (WRIA) may choose to collaborate on a single basin -level monitoring plan. S9.A through E. Submit an annual report that discusses the status of each component of the SWMP. The Permittee is to use the Annual Report Form for Cities, Towns and Counties. The annual report is to include: E.4. a. A summary of barriers to the use of LID measures within the jurisdiction. E.4.b.A report that identifies: LID practices currently available or reasonably implemented in the jurisdiction Potential LID techniques Metrics to promote and measure LID use Schedule for requirements /implementation of LID on a broader scale within the jurisdiction 2/16/2010 n/a City performs record - keeping. None of the water bodies within the City's jurisdiction currently has a TMDL. The City therefore has no obligations under this section of the NPDES permit. 12/31/2010 None. 3/31/2011 and annually on March 31 The City produces the required annual report and posts it on the City website. None. Complete SWPPP for Tukwila Golf Links Maintenance Center Perform more robust, computer - based record - keeping system. None at this time under current permit cycle; (see requirements anticipated for next permit cycle, Plan Section 3) Consider joining the regional stormwater monitoring network of Puget Sound entities proposed to Ecology. (see stormwater monitoring requirements anticipated for next permit cycle, Plan Section 3) None at this time Maintenance and Operations (see Section 7) Maintenance and Operations (see Section 7) Record - Keeping and Annual Reporting (see Section 7) Regulations (see Section 7) Regulations (see Section 7) N/A N/A = not applicable Sources of information include the following: • NPDES Phase 2 Permit (Western Washington Phase II Municipal Stormwater Permit (modified June 17, 2009; Ecology reissued it unmodified on August 1, 2012 at legislative direction to be effective through July 31, 2013. This document has an effective date of September 1, 2012. The updated 2013 -2018 permit will become effective on August 1, 2013) • Tukwila's 2010 Stormwater Management Program (March 2010) and Tukwila's 2011 Stormwater Management Program (March 2011) • Tukwila's annual Ecology Report Form for Cities, Towns and Counties (2009) WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX C -9 APPENDIX C SURFACE REGULATIONS AND POLICIES Potential Changes to Surface Water Regulations This plan includes a discussion of potential changes to the following regulations: • Endangered Species Act listings • NPDES Phase II, including LID, monitoring, and potential TMDL pollution reduction requirements Endangered Species Act The listing of coho salmon as a species of concern highlights the need to protect and restore salmon rearing, foraging, and migration areas in Gilliam, Riverton, and Southgate creeks within the City of Tukwila's boundaries. If additional species are listed or current listings are downgraded, the City's surface water program will need to be re- prioritized to place greater emphasis on habitat protection and restoration measures for these additional species. NPDES Phase 11 Permit The City of Tukwila is covered under the Washington State Department of Ecology's NPDES program for municipalities as a 'small MS4' with a Phase II municipal stormwater Permit. The current Western Washington Phase II Municipal Stormwater Permit was issued on January 17, 2007 (with an effective date of February 16, 2007), was modified on June 17, 2009, with an expiration date of February 15, 2012. The Washington State Department of Ecology reissued the Phase II permit unmodified on August 1, 2012 at legislative direction to be effective starting September 1, 2012 through July 31, 2013. Ecology will finalize the current draft of the updated 2013 -2018 permit, which will become effective August 1, 2013. While a draft of the new permit has not been finalized, preliminary draft language regarding stormwater monitoring and low impact development (LID) requirements has been distributed for comment. Based on this draft language, it is anticipated that the new Phase II permit will include requirements for both stormwater monitoring and LID implementation. However, specific requirements are not yet known. It is anticipated that the new permit will contain other changes in addition to stormwater monitoring and LID implementation. However, the extent and impact of these are not yet known. Therefore, this section focuses on potential requirements for stormwater monitoring and LID implementation. Stormwater Monitoring The rationale behind the anticipated stormwater monitoring requirements is that monitoring is necessary to characterize the effectiveness of stormwater management investments. Monitoring results are intended to steer future policy and future capital investments. The preliminary draft language in the Phase II permits proposes collaborative implementation of a new regional stormwater monitoring program. Costs of this program would be shared among all permittees and Ecology administers the contracts. Individual permittees would not have specific monitoring requirements according to this preliminary draft language. All permittees are still required to sample outfalls and receiving waters as necessary to identify illicit discharges and implement water quality improvement plans. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX C -11 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN The impact of these anticipated stormwater monitoring requirements on Tukwila's stormwater program will be mainly financial. Since Ecology will administer the program, significant staff time is not anticipated to be required. Low Impact Development The preliminary draft language calls for three levels for local government implementation: • Adopt site and subdivision requirements that require list of LID BMPs or compliance with performance standard using methods of choice. The LID techniques are mandatory unless infeasible for the site as determined using proposed feasibility criteria. • Update development codes, roles, and standards to require LID principles, such as ways to conserve native vegetation and minimize impervious surfaces, in site design. • Perform watershed -scale stormwater planning in areas where urban areas are expanding or impervious surface is increasing, in order to identify and prevent urban stormwater pollution and further habitat damage. The intent of this last bullet is to address the stormwater problem through land use, referring to watershed -scale LID rather than a traditional capital project in one location. A May 2011 publication from Ecology (publication number 11 -10 -034) acknowledges that there is considerable experience with the first two bullets above and much less with the third bullet, watershed -scale LID. That same publication states that it is not possible to maintain water quality and habitat in Puget Sound lowland streams without considering land -use and how the landscape is developed. All three of the anticipated LID requirements require political and /or planning action rather than implementation of capital projects. The first two items involve modification of Tukwila code. The third involves watershed planning. A possible approach for the watershed planning is to use this 2013 Surface Water Comprehensive Plan to identify the highest priority watersheds to take to the next level of planning as required by this last bullet. The priority watersheds may be those identified as containing the most growth or re- development in earlier sections of this Plan. The impact of these anticipated LID requirements on Tukwila's stormwater program is difficult to quantify at this stage. However, significant staff time may be required for the first two bullets, as they involve changes to city code and standards. The third bullet would be more of a financial impact, as the technical work could be done by an outside consultant, saving limited staff time. Establishment of a TMDL for the Green and Duwamish River System Ecology is required to establish a TMDL for each pollutant identified in each impaired water body on the Section 303(d) list. The Green /Duwamish River system is listed as Category 5 (impaired) for pH, dissolved oxygen, fecal coliform, and temperature. (A complete list of 303(d) listings is included in Table B -2 of Appendix B of this Plan). While a TMDL is not yet established, it is anticipated that a TMDL will be established in the future. Ecology can use mechanisms such as the municipal NPDES permit program to establish water quality control requirements for individual drainage basins. If TMDL requirements were to be incorporated into the NPDES permit mechanism, the earliest this would occur is with the C -12 WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX C SURFACE REGULATIONS AND POLICIES next permit cycle (beginning approximately July 2017, five years after the effective date of this next permit). Before this can occur, Ecology would spearhead establishment of the TMDL using data collection and modeling. The impact of the anticipated TMDL on Tukwila's surface water program during this surface water planning cycle is likely in the form of staff time or financial resources during the technical portion of establishment of the TMDL. Recommended Improvements to Tukwila's Surface Water Management Program This sub - section contains a summary of the recommended improvements to Tukwila's Surface Water Management Program needed in order to more fully comply with applicable regulations. These recommendations are also shown in Section 7 of the Plan. Environmental Species Act • Update the SEPA ESA screening checklist to include Coastal -Puget Sound bull trout and Puget Sound steelhead State Salmon Recovery Planning Act • City has implemented capital improvement projects that restore fish habitat for ESA - listed species but should identify, plan, and implement more habitat restoration projects. NPDES Permit Education • Increase opportunities for public involvement in environmental stewardship activities; reach out to children, students, adults, and visitors. • Develop and disseminate information to the public. Public Involvement • Hold public meeting and public comment period on the SWMP. Inspections and Enforcement and Illicit Detection and Elimination • Plan for periodic updating of City's surface water system inventory; inventory should include new infrastructure brought on -line since previous update (such as for new and re- development). • Complete inspections of the City's stormwater system. As needed, complete cleaning of stormwater lines in order to allow inspections to occur. • Perform inventory of private stormwater facilities. City to make policy decision regarding responsibility for maintenance of private stormwater facilities. • Enhance the City inspection program to reduce noncompliance with BMP requirements and water quality violations. • Identify procedures for characterizing, tracing, and removing illicit discharges WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX C -13 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN • Develop and carry out systematic inspections of construction sites. Document inspections and any enforcement actions. Maintenance and Operations • Develop a permanent vactor waste treatment facility or reach an agreement with another municipality to use an existing facility. • Perform more robust documentation of inspections, maintenance activities, compliant response, etc. Record - keeping • Enhance tracking and reporting to ensure maintenance, inspections, and enforcements are conducted and documented adequately. Future NPDES Phase II requirements • City should respond to any new and additional requirements in the next NPDES Phase II permit cycle, which may include requirements for water quality monitoring and implementation of low impact development where feasible. C -14 WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX D Surface Water Issues and Solutions (SUPPORTING INFORMATION FOR PLAN SECTION 4) APPENDIX D Surface Water Issues and Solutions This Appendix D contains an inventory of the drainage, water quality, and aquatic habitat issues identified in the City of Tukwila. The information presented here is summarized in Section 4 of this Surface Water Comprehensive Plan. Note that the City of Tukwila maintains a Small Drainage Project list to address the minor drainage issues that existing throughout the City. Some, but not all, of these minor drainage problems are identified in this Appendix. This Appendix (and this Plan) focuses on the major surface water problems and therefore should not be considered a complete list of surface water issues. Table D -1 contains an inventory of the surface water issues identified in this planning effort. This surface water issue inventory is organized by drainage basin, with the following eight drainage basins located wholly or partially in the City of Tukwila: • Green /Duwamish River Mainstem • Gilliam Creek • Nelson Place - Long Acres • P17 • Riverton Creek • Southeast Central Business District (CBD) • Southgate Creek • Johnson Creek Green /Duwamish River Mainstem Basin Drainage Issues Right -of -way and private property drainage issues occur along S 143rd Street, east of Interurban Avenue. No formal drainage system exists along South 143rd Street, and flooding occurs about every 2 to 5 years. Drainage issues occur on 53rd Avenue South, east of I -5 near S 139th. A damaged and / or undersized drainage system causes flooding along 53rd Avenue S, which occurs about once every 5 years. Historically, there has been a localized drainage issue at S 112th Street and Tukwila International Boulevard west of E Marginal Way. Localized ponding has occurred on private property due to sheet flows from International Boulevard. This problem has not been experienced over the last several years even through significant storm events. It is probable that the issue has been addressed because of improvements made on private property. A localized drainage issue exists at 49th Avenue S and S Hazel Street in Tukwila. This is a general low spot with no observed outlet. WBG031611103411SEA 1TUKWILASURFACEWATERCOMPPLAN FINAL V2.DOCX D -1 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN A series of four stormwater outfalls exist along E. Marginal Way S within the City of Tukwila. Two of the outfalls are owned by King County, a third has been decommissioned (Jorgenson Forge), and the fourth outfall is currently owned by Boeing. The major storm pipe flowing north along Andover Park West currently discharges to a State of Washington Department of Transportation (WSDOT) -owned pipe that flows east to the Duwamish River. With the widening of I -405, the connection was covered leaving no access to this junction. This stormwater line serves much of the central retail area in Tukwila. Water Quality Issues Four sections of the Green /Duwamish River within the City of Tukwila do not meet water quality standards according to the 2008 303(d) list. Both the Green River and Duwamish River are listed as Category 5 (at least one designated use is impaired) for dissolved oxygen, temperature, pH, and fecal coliform, based on water sampling and analysis. While stormwater originating in the City of Tukwila does contribute to water quality in the Green /Duwamish River system, other contributions from upstream sources outside of the City's management and control have a significant contribution to the impairment. Most of the City of Tukwila's stormwater outfalls to the Green and Duwamish River have no water quality treatment. Riverbank erosion is currently occurring along the length of the Green and Duwamish Rivers within the City of Tukwila. Two example locations are the East bank of the Duwamish River at S 104th and on the East bank adjacent to S 115th St between 42nd Avenue S and E Marginal Way S. Riverbank erosion is a water quality concern. Also, places that are currently experiencing riverbank erosion may be candidates for restoration projects and are therefore an aquatic habitat opportunity. The Norfolk Basin, partially within the City of Tukwila, discharges to the Lower Duwamish Waterway and includes both stormwater runoff and occasional combined sewer overflows. Of the numerous chemical parameters analyzed in the storm sewers, phthalates and zinc consistently exceeded the cleanup screening level (CSL), above which adverse impacts on marine organisms would be likely. Total petroleum hydrocarbons were also consistently high. In 2007, Ecology produced a Source Control Action Plan for Early Action Area 7 (the Norfolk Basin) (Ecology and Environment 2007). The plan lists a number of potential upland sources of contaminants to the stormwater system. Through a memorandum of agreement, the City of Seattle is conducting inspections to determine the sources of contaminants. The Action Plan also calls for better as -built storm sewer drawings and the use of Geographic Information System (GIS) to better delineate the stormwater system in this area. Aquatic Habitat Issues The riparian corridor of the river is significantly degraded from its natural condition in many areas of the city, such as along Foster Golf Course, north of SR 599, and east of Southcenter Mall. Productive, good quality fish habitat, both in the main channel and in off - channel refuge, is generally lacking. Little, if any, spawning habitat exists in the river reaches within the City. The City of Tukwila is moving forward with the Duwamish Gardens project located on the Duwamish River near the E Marginal Way South crossing. This project will provide off - channel refuge habitat for salmonids. In addition to the Duwamish Gardens project, there are D -2 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX D SURFACE WATER ISSUES AND SOLUTIONS opportunities to enhance and / or restore aquatic habitat up and down the length of the Green and Duwamish Rivers in the City of Tukwila. A possible opportunity is on the east bank of the Duwamish River at S 104th Street, an area currently experiencing riverbank erosion. Gilliam Creek Basin Drainage Issues The 12 -inch drainage pipe serving Christensen Road is undersized and possibly collapsing and is therefore in need of replacement with a larger -sized pipe. Localized drainage issues have occurred along S 146th Street, S 148th Street, S 150th Street, and S 152nd Street between 42nd Avenue S to Tukwila International Boulevard. The problems along S 146th Street have been addressed previous to this Plan and the problems along 150th will be addressed in 2014. The problems at S 148th Street and S 152nd Street remain. The existing Gilliam Creek culvert under 42nd Avenue S is lacking adequate conveyance capacity during large storms. The 48 -inch storm pipe located underneath Andover Park West is reported to be in poor condition. Water Quality Issues Gilliam Creek's use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because Gilliam Creek enters the Green River upstream of the confluence with the Black River. Water quality in Gilliam Creek is thought to be consistent with other urbanized creeks in the Puget Sound Area showing elevated levels of fecal coliform, elevated temperatures, and low dissolved oxygen levels. Temperature, dissolved oxygen, pH, and fecal coliform are the constituents of concern in Gilliam Creek based on the Category 5 (impaired) listings of the Duwamish River and the Green River. In addition to these parameters, total suspended solids and turbidity are also of concern. No site - specific water quality problems were identified in the Gilliam Creek basin. While some water quality data is available for Gilliam Creek, additional water quality data should be collected to characterize water quality conditions in Gilliam Creek. This data will help in determining an approach for addressing any water quality concerns. Aquatic Habitat Issues Habitat in the lower reach of Gilliam Creek is available to fish through the flap gate at the outlet of Gilliam Creek only under certain high flow conditions, when the Green River water level is elevated but remaining lower than the water level in Gilliam Creek. A WSDOT -owned culvert that conveys at least 1,000 feet of the creek under the south shoulder of I -405 is identified as a partial fish barrier (Washington Department of Fish and Wildlife [WDFW], 2010). Farther upstream, a log at the inlet of the WSDOT -owned culvert at the I -405 on -ramp observed in spring of 2011 appears capable of blocking fish passage. Removal of the log would allow anadromous fish greater access to the rest of the lower reach, up to the culvert at the 1 -5/1 -405 interchange, which is currently impassable to fish (WDFW, 2010). WDFW determined that several of the tributaries to upper Gilliam Creek provide some rearing habitat (WSDOT, 2007). Coho salmon and other anadromous fish are not expected to be able to reach the habitat in these upper reaches until fish passability is improved at the I -5/1 -405 interchange and immediately upstream of the interchange, where there are several other WSDOT- and City -owned culverts identified as fish passage barriers (WDFW, 2010). WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX D -3 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Fish barriers do exist in the upper reaches of Gilliam Creek, including a WSDOT -owned culvert beneath SR 518 that conveys one of these tributaries that is identified as a total fish passage barrier. The Gilliam Creek culvert under 42nd Avenue S currently is a total blockage to fish passage. Tukwila plans to replace the deteriorating culvert at 42nd Avenue S with a fish - passable structure. Just upstream of this culvert is a dam -like structure that is a total fish passage barrier, and appears to be privately -owned Removing both of these barriers would immediately improve resident fish access to the limited rearing habitat in this reach. Nelson Place — Long Acres Basin Drainage Issues The area bounded by SR -181, the Green River, the Burlington Northern Railroad, and Strander Boulevard experiences localized drainage issues. There is no functional outlet to the drainage network in this area. Water Quality Issues The Nelson Place - Long Acres drainage basin use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. The City of Tukwila is currently using a site within the Nelson Place - Long Acres basin to dispose of solids collected in vactor trucks. The material sits at the site and gradually decants. The site is located near Nelson Place. Aquatic Habitat Issues The former alignment of the Green River, prior to construction of I -405 in 1962, extended through the Nelson farm property and into the property currently occupied by Homestead Studio Suites. An oxbow of that former river alignment has been filled, isolating a pond area and reducing off - channel habitat and floodplain connectivity in this reach of the river. This is a habitat restoration opportunity for the City of Tukwila. Partnerships with other jurisdictions and regulatory agencies would be necessary, acknowledging that flood protection is necessary for proximate land owners. P17 Basin Drainage Issues Sediment is thought to have accumulated in significant quantities in the stormwater conveyance system within the P17 basin. While not a drainage issue currently, this significant buildup of sediment could potentially cause a severe localized drainage issue. In addition, because of the sediment buildup, City crews have not been able to inspect the conveyance system and therefore do not know its condition. Portions of the conveyance system that require cleaning and inspection include the following: • Andover Park E from 180th to Minkler • 36 -inch pipe from Minkler to Azteca • Andover Park W from Tukwila Pkwy to 180th D -4 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX D SURFACE WATER ISSUES AND SOLUTIONS • Minkler from Southcenter to ditch at Andover West • From Minkler to industry drive It is possible that, after cleaning and inspection, individual improvement projects will be identified. The 48 -inch pipe along Andover Park (in the Gilliam Basin) is one location that City staff have identified as a potential problem. Cleaning and inspection will provide more information. City of Tukwila's stormwater pump station #15 is located within this P17 drainage basin. Improvements to pump station #15 are planned for 2013 as part of a capital improvement project. Water Quality Issues The P17 drainage basin use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. No site - specific water quality issues were identified in this basin other than the potential water quality impact of sediment load currently contained within the stormwater pipes in the basin (mentioned above). Aquatic Habitat Issues Apart from along the mainstem of the Green River, which is described in an earlier section of this Appendix, no fish habitat opportunities were identified in this basin. Riverton Creek Basin Drainage Issues Localized drainage issues occur in the stormwater system along E Marginal Way between the SR -599 ramp and S 124th Street. The setup of the drainage network in this area is likely not optimal. Water Quality Issues The Riverton Creek use -based classification is Salmonid Spawning /Rearing and Secondary Contact Recreation, because the drainage discharges to the Duwamish River downstream of the confluence with the Black River. Water quality in Riverton Creek is thought to be consistent with other urbanized creeks in the Puget Sound Area showing elevated levels of fecal coliform, elevated temperatures, and low dissolved oxygen levels. Temperature, dissolved oxygen, pH and fecal coliform are the constituents of concern in Riverton Creek based on the Category 5 (impaired) listings of the Duwamish River and the Green River. In addition to these parameters, total suspended solids and turbidity are also of concern. No site - specific water quality problems were identified in the Riverton Creek basin. Water quality data should be collected to characterize water quality conditions that will help in determining an approach for addressing any water quality concerns. Aquatic Habitat Issues The flap gate at the Duwamish River is impassable to fish during high tides and high river flows. This flap gate should be modified and /or replaced to allow fish access to mainstem WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX D -5 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Riverton Creek. One of the gates failed in 2000, and now, during high flow events, river water backs up through that culvert into the lower reach of the creek. The East Fork of Riverton Creek just upstream of the SR 599 culvert is characterized by a wide, exposed, sandy and silty streambed that provides fish passage but no spawning or rearing habitat. Upstream of that reach, a more than 2,000 - linear -foot (LF) culvert likely prevents at least some anadromous fish from accessing suitable habitat located in the upper reach between S 126th Street and S 128th Street, where good overhead cover from riparian plants, sufficient flows, and streambed gravel appear suitable for coho salmon spawning. This 2000 LF culvert is considered a partial fish blockage. Little is known about the condition and characteristics of this culvert. Inspection of this culvert would provide more information to help in deciding if replacement or channel day - lighting is feasible and beneficial. Southeast CBD Basin Drainage Issues No site - specific drainage issues were identified in this basin. Water Quality Issues The use -based classification for the Southeast CBD Basin is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. No site - specific water quality issues were identified in this basin. Aquatic Habitat Issues Apart from along the mainstem of the Green River, which is described in an earlier section of this Appendix, no fish habitat opportunities were identified in this basin. Southgate Creek Basin Drainage Issues The drainage network near 5 146th Street and 35th Avenue South is under capacity to serve the area. A landslide occurred several years ago on S 131St Street near 44th Avenue South. This landslide is both a drainage and a water quality issue. Water Quality Issues The Southgate Creek use -based classification is Salmonid Spawning /Rearing and Secondary Contact Recreation, because the drainage discharges to the Duwamish River downstream of the confluence with the Black River. Water quality in Southgate Creek is thought to be consistent with other urbanized creeks in the Puget Sound Area showing elevated levels of fecal coliform, elevated temperatures, and low dissolved oxygen levels. Temperature, dissolved oxygen, pH, and fecal coliform are the constituents of concern in Southgate Creek based on the Category 5 (impaired) listings of the Duwamish River and the Green River. In addition to these parameters, total suspended solids and turbidity are also of concern. This is especially true in Southgate Creek given the sediment load observed in the lower reaches of the creek. D -6 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX D SURFACE WATER ISSUES AND SOLUTIONS Water quality data should be collected to characterize water quality conditions in Southgate Creek. This data will help in determining an approach for addressing any water quality concerns. Aquatic Habitat Issues The fish ladder at the Southgate culvert under SR 599 likely is a fish barrier to anadromous fish during low stream flows. Bank erosion from the combination of steep gradients and stormwater runoff from urban development have deposited sediments in the lower reach, which have reduced effective culvert conveyance capacities and covered up salmon spawning gravels. The section of the main stem just downstream of the confluence of the West and East Forks is often completely blocked by sediment and debris. Improving this section of the main stem Southgate Creek along S 132nd Street would allow anadromous fish greater access to the spawning and rearing habitat in the recently- restored lower west fork and rearing habitat in the east fork. Johnson Creek Basin Drainage Issues No site - specific drainage issues were identified in this basin. Water Quality Issues The Johnson Creek use -based classification is Salmonid Spawning /Rearing and Primary Contact Recreation, because the drainage discharges to the Green River upstream of the confluence with the Black River. Water quality in Johnson Creek is thought to be consistent with other urbanized creeks in the Puget Sound Area showing elevated levels of fecal coliform, elevated temperatures, and low dissolved oxygen levels. Temperature, dissolved oxygen, pH, and fecal coliform are the constituents of concern in Johnson Creek based on the Category 5 (impaired) listings of the Duwamish River and the Green River. In addition to these parameters, total suspended solids and turbidity are also of concern. However, no site - specific water quality problems were identified in the Johnson Creek basin. Water quality data should be collected to characterize water quality conditions in Johnson Creek. This data will help in determining an approach for addressing any water quality concerns. Aquatic Habitat Issues The Johnson Creek flap gate and outfall to the Green River were replaced as part of mitigation for the proximate commercial development. No other barriers to fish passage were identified in Johnson Creek. No other aquatic habitat opportunities were identified in this basin. Mill Creek Basin Drainage Issues No site - specific drainage issues were identified in this basin. Water Quality Issues No site - specific water quality issues were identified in this basin. WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX D -7 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Aquatic Habitat Issues No site - specific habitat issues were identified in this basin. D -8 WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX D SURFACE WATER ISSUES AND SOLUTIONS TABLE D -1 Surface Water Issues and Solutions ID Problem Description Location Issue Drainage Type Basin Possible Solutions' Recommended Solution 1 Outfalls discharge directly All outfalls are potential candidates; Water All to receiving water, no 48th Ave S and S 122nd are two quality treatment top candidates 2 Ponding in low spot, possible ponding on the east side of road 3 Dumping 4 Lack of off- channel salmon habitat along lower Duwamish 5 E Marginal Way S Stormwater Outfall 6 Duwamish River riverbank at S 104th St is eroding, causing failure of road shoulder and habitat degradation 7 Duwamish River riverbank at S 115th St is eroding, causing failure of road shoulder and habitat degradation 8 53rd Ave S storm drain system has inadequate capacity 49th Ave S and S Hazel Street S 114th St and 49th Ave S Duwamish River near light rail crossing North end of Tukwila, along east shore of Duwamish River; 4 outfalls proximate to S 87th Place Duwamish River right (east) bank at S. 104th St Duwamish River right (east) bank adjacent to S 115th St between 42nd Ave S and E Marginal Way S and adjacent to 42nd Ave S from S 115 St to Interurban Ave S. 53rd Ave S near S 139th WBG031611103411 SEAITU KW I LASURFACEWATERCOM PPLAN_FINAL_V2. DOCX Programmatic (inspections /enforcement, illicit discharge detection and elimination, maintenance) or capital (point source control, water quality treatment) Drainage Duwamish Capital (increase conveyance capacity, retention /detention) Water Duwamish Cleanup of dumped material quality Habitat Duwamish Capital (channel physical habitat restoration) Drainage Duwamish Programmatic (inspections /enforcement, illicit discharge detection and elimination, maintenance) or capital (retrofit system, abandon existing outfalls) Water Duwamish Capital (channel stabilization) or quality close the road Water Duwamish Capital (physical habitat quality restoration; channel stabilization) Drainage Duwamish Capital (increase conveyance capacity, provide drainage system, detention /retention) Water Quality Retrofit Program (capital project) Move onto 2013 Small Drainage Project List To be addressed by others2 Physical habitat restoration (capital project - Duwamish Gardens) Retrofit system / outfall(s) (capital project) To be addressed by others2 To be addressed by others2 Increase conveyance capacity (capital project) D -9 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN TABLE D -1 Surface Water Issues and Solutions ID Problem Description Location Issue Drainage Type Basin Possible Solutions' Recommended Solution 9 S 143rd St has no drainage system 10 Tukwila stormwater line discharges to WSDOT pipe, no access due to 1-405 widening 11 Andover Park 48 inch stormwater pipe in poor condition, possibly damaged 12 Gilliam Creek flapgates as fish barrier 13 Christensen Rd 12" pipe is undersized (replace with 18 ") 14 Gilliam Creek culvert at 42nd Ave SE is undersized 15 Northwest Gilliam Storm Drainage System has inadequate capacity - S 152nd and S 148th 16 Cleaning /Inspection of Stormwater Conveyance 17 Storm Lift Station No. 15 improvements S 143rd St, east of Interurban Ave; S 144th St, S 143rd Place, S 143rd S, east of Interurban Ave S between Interurban and Duwamish River, W. Of Duwamish, near Black River convergence Andover Park W at Gilliam Creek Andover Park W Outlet of Gilliam Creek to Green River - partial fish blockage Christensen Rd Gilliam Creek crossing at 42nd Ave SE (between S 154th and Hwy 518) From 42nd Ave S to Tukwila International Blvd S 146th St, S 148th St, S 150th St, S 152nd St Various - commercial area at Mall and surrounding Near Claim Jumper - 5880 S 180th Drainage Duwamish Capital (provide drainage system) Provide drainage system (capital project) Drainage Duwamish Capital (re -route drainage system) Re -route drainage system (capital project) Drainage Gilliam Capital (increase effective Creek conveyance capacity) Drainage/ Gilliam Capital (modify /remove to allow fish habitat Creek Drainage Drainage/ Gilliam habitat Creek Drainage Gilliam Creek passage) Gilliam Capital (increase capacity) Creek Water All quality / drainage Capital (increase conveyance capacity, replacement of culvert to be fish - passable) Capital (increase conveyance capacity, re -route existing drainage system, detention /retention, high flow bypass) Capital (conveyance system cleaning and inspection) Drainage P17 Capital (needed upgrades, updating) No capital project at this time; address once collection system has been clean and inspected retrofit for fish passage; provide flood protection (capital project) Increase capacity (capital project) Replace culvert (capital project) Increase capacity (capital project) Conveyance system cleaning and inspection (capital project) Upgrade pump station (capital project) D -10 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX D SURFACE WATER ISSUES AND SOLUTIONS TABLE D -1 Surface Water Issues and Solutions ID Problem Description 18 Location Issue Drainage Type Basin Possible Solutions' Recommended Solution Permanent home for soils reclamation facility 19 No functional outlet to drainage network at Nelson /Longacres 20 Former river oxbow has bren blocked off from River 21 Storm system along E Marginal Way is bad setup, causes ponding 22 Fish habitat accessibility issues in Riverton Creek culvert 23 Riverton Creek Flap Gate is partial fish passage barrier 24 S 146th St pipe and 35th ave s drainage - needs additional capacity 25 Sediment/clogging issues proximate to Southgate Creek 26 Historical landslide - road closed Vactor waste dump site / decanter Water facility, currently using an area near quality Nelson Place Area bounded by SR 181, Green Drainage River, Burlington Northern RR, and Strander Blvd Nelson farm property between Green River and W. Valley Highway E Marginal Way between SR599 ramp and S 124th St E Marginal Way south of SR599 Riverton outfall into Duwamish River S 146th St between Military Rd S and Pac Hwy S S 131st St near 44th Ave S S 137th St at 44th Ave S Habitat Drainage Habitat Habitat Drainage Drainage, water quality Drainage, water quality Nelson/ Capital (land acquisition for soils Longacres reclamation facility) Nelson/ Capital (provide drainage system, Longacres on -site detention /retention) Nelson/ Capital (channel physical habitat Longacres restoration) Riverton Creek Capital (increase conveyance capacity, re -route drainage, detention, high flow bypass) Riverton Capital (removal /replacement of Creek fish - blocking culvert) Riverton Capital (modify /remove to allow fish Creek passage) Southgate Creek Capital (increase conveyance capacity, detention /retention, high flow bypass) Southgate Regrading of wetlands on private Creek property Southgate Creek Capital (complete channel stabilization and riparian buffer restoration) Land acquisition (capital project) Provide outlet to drainage system (capital project) Restore Nelson Salmon Habitat Side Channel (capital project) Proximate to Riverton Creek culvert (below), so addressed together Conveyance system cleaning and inspection (capital project) Remove flapgate (capital project) Increase conveyance capacity (capital project) To be addressed by others2 No capital project at this time; monitor status and review during next planning period Notes: 1 Possible solutions address the surface water problem in whole or in part 2 Problem to be addressed by others because responsibility /opportunity lies in other City department or with other jurisdiction WBG031611103411SEA1TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX D -11 APPENDIX E Surface Water Capital Projects (SUPPORTING INFORMATION FOR PLAN SECTION 5) APPENDIX E Surface Water Capital Projects This Appendix E contains a summary of the recommended surface water capital projects. The information presented here is summarized in Section 5 of this Surface Water Comprehensive Plan. The City of Tukwila has requested that CH2M HILL update the City's Comprehensive Surface Water Management Plan to provide a "living" document that will guide the City's surface water management activities for the next planning period. A major component of the Plan is identified surface water management issues and corresponding solutions to those issues. The Plan identifies both programmatic (non- structure) and capital project (structural) solutions to those issues. The purpose of this appendix is to outline the capital projects recommended for implementation in the Plan. Attachment A to this Appendix contains the basis for the cost estimates for each of the capital projects recommended for inclusion in Tukwila's CIP. Attachment B to this Appendix contains the summary sheets for each of the capital projects that can be utilized as part of the budget planning process and CIP development. Capital Projects Capital Project Development The surface water needs, or issues, were identified as part of Comprehensive Surface Water Management Plan development. Needs were categories as drainage, water quality, or aquatic habitat needs. Once these needs were identified, one or more potential solutions were identified. These solutions were either programmatic or structural (capital) in nature. CH2MHILL and City of Tukwila staff collaborated on the preferred solution for each surface water need identified. CH2MHILL developed preliminary design concepts and planning -level cost estimates for each capital project. Most of the capital projects presented in this memorandum are focused on rectifying discrete drainage or aquatic habitat problems. Some of the surface water management problems identified are not readily solved using discrete capital projects. For example, widespread water quality problems in urban runoff entering Riverton, Southgate, and Gilliam Creeks are difficult to address with capital improvements. Very few water quality projects have been developed because individual, small -scale runoff treatment system retrofits would make only an incremental difference in receiving water quality. It is more appropriate to address most of the water quality problems with land use or storm water management regulations (for example, requiring water quality treatment for redevelopment projects). The water quality projects that have been developed and are described in this section either are targeting a drainage or habitat issue and have water quality benefits, or else are the recommended first projects as part of a larger program to address water quality. E -1 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Capital Projects Recommended for Inclusion into the CIP Table E -1 presents the capital projects recommended for inclusion into Tukwila's Surface Water CIP. Attachment A to this memorandum contains the basis for the cost estimates. Attachment B contains project summary sheets with project scopes, benefits, schematic sketches, and cost estimates for each project. TABLE E -1 Recommended Capital Projects ID Estimated Total Project Cost (March 2012 Project Name Drainage Basin dollars) 98641222 S 143rd St storm drain system Duwamish River $1,096,000 98741202 Nelson /Longacres — Phase II Nelson /Longacres $678,000 98941202 Christensen Rd. pipe replacement Gilliam Creek $327,000 99341208 Gilliam Creek 42nd Ave S culvert Gilliam Creek $702,000 99441202 Soil Reclamation Facility Nelson /Longacres $3,504,000 90341206 Northwest Gilliam Storm Drainage Gilliam Creek $1,978,000 System 90341213 53rd Ave S storm drain system Duwamish River $1,557,000 90341214 S 146th St pipe and 35th Ave S drainage Southgate Creek $882,000 91041203 Storm Lift Station No. 15 Improvements P17 $698,000 91041204 E. Marginal Way S Stormwater Outfall Duwamish River $772,000 91241201 Water Quality Retrofit Program Duwamish River $287,000 91241202 Tukwila Pkwy /Gilliam Cr Outfalls Gilliam Creek $278,000 91241203 Tukwila Urban Center Conveyance Gilliam Cr. /P17 $541,000 Inspections 91041204 E. Marginal Way Conveyance Inspection Riverton Creek $85,000 90330104 Nelson Side Channel Nelson /Longacres $1,497,000 90630102 Duwamish Gardens Duwamish $3,000,000 99830103 Riverton Creek Flap Gate Removal Riverton Creek $946,000 99830105 Gilliam Creek Fish Barrier Removal Gilliam Creek $816,000 Capital Projects Recommended for Removal from the CIP Several capital projects developed in previous Comprehensive Stormwater Plans and appearing in previous CIPs are recommended for removal from the CIP for one or more of the following reasons: • Surface water issue is located on private property. E -2 WBG031611103411SEA1 TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX E SURFACE WATER CAPITAL PROJECTS • Alternative solutions are already under further development (that is, design and construction). • Alternative solutions were developed under a different capital project included in the CIP. • Issue will be monitored over time and considered for inclusion in the CIP during the next planning period • Issue will be further characterized with information gathered in this next planning cycle and will be considered for inclusion in the CIP during the next planning period • Issue will be addressed by other parties besides the City of Tukwila or by other departments within the City of Tukwila These projects are listed in Table E -2. TABLE E -2 Capital Projects Removed from the CIP ID Fund Capital Project Name 99441205 412 Duwamish Riverbank Stabilization at S 104th St. 99441209 412 Duwamish Riverbank Stabilization near S 115th St. 98641217 412 Andover Park West 48" rehabilitation 90341205 412 Tukwila Parkway Drainage 90341207 412 Treatment Pond for Gilliam Creek 90341208 412 Minkler Boulevard Culvert Replacement 90341210 412 Retrofit Stormwater Treatment at 51St Avenue S 0341211 412 Property for Riverton Creek Sediment Trap 90330106 301 Foster Golf Course Riverbank 90330116 301 Lower Gilliam Creek Channel Improvements Capital Project Descriptions 98641222: S 143rd Street Storm Drain System Project Description Because of development and increased surface water runoff, drainage issues are occurring in the right -of -way along S. 143rd Place and S. 143th Street. The design objectives are reduction of stormwater ponding and peak flow rate. A secondary design objective is to provide water quality treatment prior to discharge to the Duwamish River. Proposed Solution The proposed solution is to install an asphalt overlay, curb and a closed -pipe conveyance system along S. 143rd Street and S. 143rd Place to collect and convey the stormwater runoff to a water quality treatment device then discharge the stormwater into the Duwamish River. A flap gate will be installed in the outfall to prevent flooding when the river is at high levels. Also, the E -3 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN project will convert an existing drainage ditch into a bioswale to provide some water quality treatment. 98741202: Nelsen PI /Longacres - Phase II Project Description Because of development and increased surface water runoff, flooding is occurring in the right - of -way and on private property. The design objectives are reduction of stormwater ponding and peak flow rate. The project is located within the Burlington Northern Santa Fe (BNSF) corridor. Proposed Solution The proposed solution is to install a 48 -inch stormwater pipe crossing underneath the Burlington Northern railroad tracks connecting to a previously installed interceptor east of the tracks. This 48 -inch stormwater pipe will be constructed using trenchless techniques to minimize the impact to the operation of the railroad. This new pipe will provide drainage from the existing drainage ditch west of the tracks to the P -1 interceptor. Ownership, easement, and maintenance responsibility will be determined and / or verified prior to moving forward with this project. 98941202: Christensen Road Pipe Replacement Project Description The existing 12 -inch storm drain pipe between the end of Christensen Road to Strander Boulevard is collapsed and causing flooding at Christensen Road. This pipe is currently located between two buildings. Temporary pumps have been used to convey water from the area when flooding occurs. Proposed Solution The proposed solution is to replace the existing collapsed pipe with an 18 -inch pipe. Because of the close proximity of the pipe trench to the adjacent buildings, shoring will be needed to provide support for the building foundations. 99341208: Gilliam Creek 42nd Avenue S Culvert Project Description The existing concrete culvert along Gilliam Creek underneath 42nd Avenue S. is in poor condition and is undersized for larger storm events. The pipe is cracked and pipe sections are separating. The failure of the culvert could result in erosion or catastrophic failure of the 42nd Avenue South roadway. Proposed Solution The proposed solution is to replace this culvert with a 16' wide open- bottom arch culvert and to rehabilitate the upstream and downstream segments of the stream channel. The project will be included in the 42nd Avenue S. Roadway Improvement project. 99441202: Soil Reclamation Facility Project Description The City maintenance crews collect sediments during typical stormwater system maintenance work tasks such as street sweeping and cleaning out stormwater inlets and pipes. The City is lacking a formal facility to efficiently dewater, treat and dispose of the waste materials. E -4 WBG031611103411SEA\ TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX E SURFACE WATER CAPITAL PROJECTS Proposed Solution The proposed solution is to build a soil reclamation facility within the City. This capital project consists of property acquisition for this facility. 90341206: Northwest Gilliam Basin Storm Drainage System Project Description Because of urban development and increased surface water runoff, flooding is occurring in the right -of -way and private property along S. 148th Street and S. 152nd Street between International Boulevard and S. 42nd Avenue South. (A similar issue has been addressed on S 146th Street. The issue will be addressed in 2014 on S 150th Street. S. 148th Street and S 152nd Street still need to be addressed and are therefore included here in this capital project.) The design objectives are reduction of stormwater surface runoff volume and reduction of peak flow rate. The project may also provide water quality treatment prior discharge to the Gilliam Creek. Proposed Solution The proposed solution includes installing new storm drain pipes along S. 148th Street and S. 152nd Street to replace the old storm drain and increase the conveyance capacity of the system. Other project elements include installation of an asphalt overlay and curbs to route water to new catch basins to reduce surface ponding. In addition, the installation of water quality treatment devices at the end of each of the blocks is also planned. Stormwater would be discharged to the existing storm drain on 42nd Avenue South. 90341213: 53rd Avenue S Storm Drainage System Project Description Because of urban development and increased surface water runoff, flooding is occurring in the right -of -way and private property along 53rd Avenue South between S. 137th Street to S. 144th Street. The existing storm drain is in poor condition and street runoff flows onto private property. The design objectives are reduction of stormwater ponding and peak flow rate and providing water quality treatment. Proposed Solution The proposed solution includes providing an asphalt overlay to the existing roadway, installing a curb to keep the stormwater runoff remain on the road, and replacing the existing storm drain system along 53rd Avenue S. to improve conveyance capacity. The project also includes the installation of bioretention swales along 53rd Avenue South or near the Lee Philip Field and Foster Memorial Park to provide water quality treatment. The upgraded storm drains will connect to an existing storm drain at S. 137th Street. 90341214: S 146th St Pipe and 35th Ave S Drainage System Project Description Because of urban development and increased surface water runoff, flooding is occurring in the right -of -way and private property along S. 146th Street immediately west of Tukwila International Boulevard. The design objectives are reduction of stormwater ponding and peak flow rate. Proposed Solution The proposed solution includes applying an asphalt overlay to the existing roadway, installing a curb to keep the stormwater runoff on the road, and replacing the existing storm drain system E -5 CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN along S. 146th Street and a segment of 35th Avenue South to improve conveyance capacity. The upgraded storm drains will connect to an existing storm drain on International Boulevard. 91041203: Storm Lift Station No.15 Improvement Project Description The study completed in 2010 recommended upgrading of this lift station to provide a higher level of reliability and protection against damage due to power failure. Proposed Solution The proposed solution includes the installation of an on -site power generator with enclosure. The power generator will provide power automatically to the lift station allowing the lift station to continue conveying stormwater runoff during power failure. 91041204: East Marginal Way South Stormwater Outfall Project Description A series of four stormwater outfalls located on private property discharge directly into the Duwamish River. Two of the outfalls (Z -line and Jorgensen Forge) are located within the Boeing property and the other two outfalls (KC Airport Lift Station and Slip -6) are owned and operated by King County. The Jorgensen Forge outfall was closed in January 2011. The stormwater runoff previously discharging from the Jorgensen Forge outfall overflowed to the King County Airport Lift Station outfall. No flooding was reported. A study completed in September 2009 by GHD (GHD 2009) evaluated 4 alternatives to this problem. Proposed Solution The proposed solution is based on the Alternative 1 from the GHD study to reuse the Z -line outfall. This alternative includes installing a new storm drain to direct the stormwater runoff from East Marginal Way South to an existing storm drain connecting to the outfall. This existing storm drain would be slip -lined to reduce the risk of cross contamination. This alternative is proposed for inclusion into the City's CIP because this alternative provides a long -term fix of the problem without the long -term maintenance cost associated with the use a stormwater lift station or paying a fee for using a third -party stormwater lift station. Ownership, easement, and maintenance responsibility will be negotiated between the City and the property owner prior the implementation of the project. 91241201: Water Quality Retrofit Program Project Description Because of existing development and the increase in surface water runoff from pollutant generating impervious surfaces, the water quality of the receiving water bodies in the City of Tukwila continues to deteriorate. The water quality retrofit program is intended to address this need as an overall water quality program with individual project(s) implemented each year. Three of the possible locations for implementation of water quality retrofits under this program are Z -line (see CIP 91041204), 48th Avenue South, and S. 122nd Street, all discharging to the Duwamish River. Proposed Solution For each location identified as part of this water quality retrofit program, several options for water quality retrofits will be evaluated. These include low impact development techniques and water quality proprietary devices. The proposed solution is based on installing a structure E -6 WBG031611103411SEA\ TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX E SURFACE WATER CAPITAL PROJECTS treatment device to provide pre - treatment. The treatment device needs to works with the existing storm drain system. The actual location and the treatment approach will be determined for each project that is implemented as part of this program. 91241202: Tukwila Parkway / Gilliam Creek Outfalls Project Description The existing 48 -inch storm drain along Andover Park West crosses Tukwila Parkway, crosses underneath a 60 -inch Seattle Public Utility water supply pipe line, and then discharges into a 108 -inch culvert owned by WSDOT installed as part of the initial construction of I -405 to convey Gilliam Creek adjacent to the freeway. This WSDOT -owned pipe discharges to Gilliam Creek. With subsequent freeway improvements and widening, the discharge point of the 48 -inch storm drain to the culvert is now underneath the freeway travel lanes. Also, the connection to the 108 - inch culvert is higher than the invert elevation of the 48 -inch pipe which can create backwater conditions in the 48 -inch pipe at Andover pipe W. This system is extremely difficult, if not impossible, for the City to inspect and maintain. In addition, a backwater condition within City pipes for several hundred feet prevents inspection and cleaning. Proposed Solution The proposed solution is to install a new 84 -inch manhole structure on the existing 48 -inch pipe and a new 72 -inch structure on the 30 -inch pipe west of Lowe's. A slide guide with a discharge port would be installed in each of the new structures. 91241203: Tukwila Urban Center Conveyance Inspections Project Description The network of storm pipes in the core retail area of Tukwila has not been inspected in the last several decades. Because there have been no inspections, pipe condition is unknown and rehabilitation, repair, and replacement needs are therefore unknown. It is likely that a significant amount of sediment exists within the storm network in that area. Several stormwater pipes have been selected as higher priority because of the large pipe sizes and more significant impact should a pipe fail. The selected area includes 1)Andover Park E from S. 180th Street to Minkler Boulevard, 2) 36" pipe from Minkler Boulevard to Azteca Restaurant, 3) Andover Park West from Tukwila Parkway to S 180th Street, 4) Minkler Boulevard from Southcenter Parkway to ditches at Andover Park West, and 5) Minkler Boulevard to Industry Drive. Proposed Solution In order to assess the pipe conditions, the storm drain pipes will be cleaned and the sediment will be disposed of. Then the pipe interior will be inspected using a remote - control camera. The inspection will be recorded. Rehabilitation, repair, and replacement needs will then be known and prioritized. 91241204: East Marginal Way Conveyance Inspection Project Description The storm drainage system along East Marginal Way near S 124th is problematic. Localize drainage issues occur. Proximate to this drainage issue, Riverton Creek flows through a long culvert that is a blockage to fish passage under certain flow conditions. CITY OF TUKWILA 2012 SURFACE WATER COMPREHENSIVE PLAN Proposed Solution These separate problems of drainage issues and fish blockages could be addressed by a joint solution. However, until more information is known, this solution cannot be fully developed. Therefore, for this planning period, Tukwila should proceed with cleaning and inspecting the Riverton Creek culvert and proximate drainage infrastructure. After the City performs the inspection, the City can determine the pipe conditions, address any issues, and proceed with development of the larger project. 90330104: Nelson Salmon Habitat Side Channel Project Description Many years ago, a natural oxbow on the Duwamish River was disconnected from the main channel as the Duwamish /Green River was engineered for flood control. Currently, this oxbow is a pond. Proposed Solution The proposed solution is to re- connect the oxbow with the main channel. The hydraulic connectivity will increase habitat for juvenile salmonids in order to increase rearing productivity. The existing embankment between the Duwamish River and the existing pond will be removed to create a backwater side channel. Boulders and large woody debris will be placed along the toe of embankment for erosion protection and creating habitat. A flood control levee will be installed along the south side of the existing pond to provide flood protection to the adjacent private property. Currently a hotel is located next to the pond. 90630102: Duwamish Gardens Project Description and Solution This on -going 2.25 -acre habitat restoration project is located within the Lower Duwamish River. The goal of this project is to provide salmon habitat and a passive park. This project is currently in the design process. 99830103: Riverton Creek Flap Gate Removal Project Description The flap gates at the outlet of Riverton Creek are impassible to fish during low flows and are somewhat impassible all other times. The flap gates have been partially propped -open as an interim solution. Proposed Solution The proposed solution is to remove the flap gates and to perform channel restoration in the lower reaches of Riverton Creek. The existing channel upstream of the existing flap gates will be enhanced and restored to provide salmonid rearing and resting habitat. 99830105: Gilliam Creek Fish Barrier Removal Project Description The flap gate at Gilliam Creek only allow fish passage at certain of high flow conditions, when the Green River water level is elevated but remaining lower than the water level in Gilliam Creek. Proposed Solution The proposed solution is to remove the fish barrier and restore the natural channel in the lower reaches of Gilliam Creek. The existing flap gate will be replaced with a self - regulating tide gate E -8 WBG031611103411SEA\ TUKWILASURFACEWATERCOMPPLANFINAL V2.DOCX APPENDIX E SURFACE WATER CAPITAL PROJECTS to allow fish access of upstream habitats. A fish ladder will be installed upstream of the tide gate to provide access to further upstream creek reaches. The Army Corps of Engineer had plans to improve this segment of Gilliam Creek. This project should be coordinated with the Army Corps of Engineers and another City of Tukwila capital project, "91241202: Andover Park W Outfall to Gilliam Creek ". Surface Water Capital Project Funding The City of Tukwila's Capital Improvement Program includes projects and program elements that are recommended for implementation in the Surface Water Management Comprehensive Plan. Projects implemented primarily for surface water management purposes are funded with Fund 412 (drainage, water quality) or Fund 301 (aquatic habitat). Projects financed under the commercial streets, water, and sewer programs may have a stormwater element. Projects with surface water components are funded under the following City Programs, in addition to Fund 412 and Fund 301: • Commercial Streets Program (Fund 104) • Water Program (Fund 403/01) • Sewer Program (Fund 403/02) References CH2M HILL. 2003. City of Tukwila Comprehensive Surface Water Management Plan. Prepared for the City of Tukwila. November. City of Tukwila. Adopted 2010 -2015 Financial Planning Model and Capital Improvement Program. December 7, 2009. GHD 2009. City of Tukwila East Marginal Way South Outfall Analysis Report, report to City of Tukwila. September. ATTACHMENT A Capital Project Cost Opinions City of Tukwila CAPITAL IMPROVEMENT PROGRAM for 2012 -2017 Enter Year: SUMMARY OF FUND # 412 2012 • NOTE: All sheets are linked to the Summary Printed: 8/31/2012 SURFACE WATER 412 Fund PROJ.# PROJECT TITLE Construction Project Land Project Total Notes Subtotal Subtotal Acquisition 98641222 5 143rd Street /Place Storm Drain System 687,000 1,096,000 0 1,096,000 Updated unit costs from 2003 98741202 Nelson PI /Longacres Ph2 - Interceptor Pipe 425,000 678,000 0 678,000 Updated unit costs from 2003 98941202 Christensen Rd Pipe Replacement 205,000 327,000 0 327,000 New estimate 99341208 Gilliam Creek Crossing at 42nd Ave 5. (93 -DR08) 489,000 702,000 0 702,000 Updated unit costs from 2003; revised for 16' width 99441202 Soil Reclaimation Facility 1,507,000 2,404,000 1,100,000 3,504,000 New estimate 90341206 Northwest Gilliam Storm Drainage System 1,240,000 1,978,000 0 1,978,000 5148th, S150th, and S152th Street. Revised from 2003 90341213 53rd Ave 5 Storm Drainage System 976,000 1,557,000 0 1,557,000 Updated unit costs from 2003 90341214 S. 146th Street Pipe and 35th Avenue S. Drainage System 553,000 882,000 0 882,000 Updated unit costs from 2003 91041203 Storm Lift Station No. 15 Improvement 467,000 698,000 0 698,000 New estimate 91041204 East Marginal Wy 5 Stormwater Outfall 469,000 772,000 0 772,000 New estimate 91241201 Water Quality Retrofit Program n/a n/a n/a 286,500 New Project. 91241202 Tukwila Pkwy /Gilliam Creek Outfalls 180,000 278,000 0 278,000 New Project. 91241203 Tukwila Urban Center Conveyance Inspections 396,000 541,000 0 541,000 New Project. 91241204 E. Marginal Way Conveyance Inspection 57,000 85,000 0 85,000 New Project. Grand Total 7,651,000 11,998,000 1,100,000 13,384,500 2012 - 2017 Capital Improvement Program 1 of 20 8/31/2012 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: S 143rd Street /Place Storm Drain System CHECKED BY: DATE: Amy Carlson BY: Raymond Chung 3/2/2012 CIP# 98641222 ITEM NO. 1 BID ITEM 1 QUANTITY _� UNIT 1 UNIT PRICE 1 AMOUNT 1 REMOVE /ABANDON PIPE 85 LF $ 23.00 $ 1,955 2 PAVEMENT OVERLAY, ASPHALT CONCRETE CL B (S 143RD STANDS 143RD PL) 1,305 TN $ 63.00 $ 82,215 3 WASHED DRAIN ROCK/STRUCTURAL FILL/PIPE BEDDING 420 TN $ 26.00 $ 10,920. 4 CURB AND GUTTER, CEMENT AND CONC. (S 143RD ST) 2,300 LF $ 22.00 $ 50,600 5 CEMENT CONCRETE SIDEWALK OR DRIVEWAY (S 143RD ST) 1,533 SY $ 40.00 $ 61,320 6 CURB RAMP, CEMENT CONCRETE (S 143RD ST) 12 EA $ 489.00 $ 5,868 7 CATCH BASIN TYPE 1 8 EA $ 1,532.00 $ 12,256 8 CATCH BASIN TYPE 2 48 " -54" 2 EA $ 4,353.00 $ 8,706 9 STORMCEPTOR WQ MANHOLE (STC 4800) 1 EA $ 53,000.00 ' $ 53,000 12 18" -24" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 500 LF $ 141.00 $ 70,500 13 8 " -12" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 1,100 LF $ 81.00 $ 89,100 14 TRENCH SAFETY SYSTEMS 16,000 SF $ 0.92 $ 14,741 15 REGRADE EXISTING DITCH 500 LF $ 5.76 $ 2,879 16 BIOSWALE SEEDING 4,000 SF $ 1.73 $ 6,910 17 18" - 24" DIAMETER FLAP GATE 1 EA $ 3,455.00 $ 3,455 18 UTILITY RELOCATIONS 1 L5 $ 11,516.00 $ 11,516 19 TEMPORARY BYPASS 1 LS $ 5,758.00 $ 5,758 Subtotal $ 491,699 DEWATERING 5% $ 24,585 EROSION & SEDIMENTATION CONTROL 2% (See Note 3) $ 9,834 TRAFFIC CONTROL 5% (See Note 4) $ 24,585 CONTINGENCY 15% $ 73,755 Subtotal $ 624,458 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 62,446 Construction Subtotal (Rounded) $ 687,000 STATE SALES TAX 9.5% $ 65,265 ENGINEERING /LEGAL/ADMIN 25% $ 171,750 CONSTRUCTION MANAGEMENT 20% $ 137,400 PERMITTING 5% $ 34,350 Project Subtotal (Rounded) $ 1,096,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 1,096,000 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road ortemporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 2 of 20 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order-of-magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 3 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: BY: Nelson PI /Longacres Ph2 - Interceptor Pipe CHECKED BY: DATE: Amy Carlson Raymond Chung 3/2/2012 CIP# 98741202 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 JACKING AND RECEIVING PIT 1 EA $ 40,883.00 $ 40,883 2 42" DIA. SMOOTH WALL INTERIOR CORROGATED POLYETHENE, JACK & BORE 225 LF $ 1,025.00 $ - 230,625 CONSTRUCTION 3 RAILROAD INSPECTOR 24 HR $ 58.00 $ 1,392 4 CATCH BASIN TYPE 2 72 " -96" 1 EA $ 14,108.00 $ 14,108 5 UTILITY RELOCATIONS 1 L5 $ 11,516.00 $ 11,516 6 TEMPORARY BYPASS 1 LS $ 5,758.00 $ 5,758 Subtotal $ 304,282 DEWATERING 5% $ 15,214 EROSION & SEDIMENTATION CONTROL 2% (see Note 3) $ 6,086 TRAFFIC CONTROL 5% (See Note 4) $ 15,214 CONTINGENCY 15% $ 45,642 Subtotal $ 386,438 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 38,644 Construction Subtotal (Rounded) $ 425,000 STATE SALES TAX 9.5% $ 40,375 ENGINEERING /LEGAIJADMIN 25% $ 106,250 CONSTRUCTION MANAGEMENT 20% $ 85,000 PERMITTING 5% $ 21,250 Project Subtotal (Rounded) $ 678,000 2% LAND ACQUISITION 0 AC $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 678,000 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order-of-magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 3 of 20 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order- of-magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual she conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these fact ors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 4 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Christensen Rd Pipe Replacement CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP# 98941202 ITEM NO. 1 BID ITEM 1 QUANTITY UNIT 1 UNIT PRICE 1 AMOUNT 1 18" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 320 LF $ 110.00 $ 35,200 2 REMOVE /ABANDON PIPE 320 LF $ 20.00 $ 6,400 3 TRENCHBOX SHORING 2,720 SF $ 2.00 $ 5,440 4 SPECIAL BUILDING SHORING 1,020 SF $ 75.00 $ 76,500 5 SETTLEMENT MONITORING 1 LS $ 10,000.00 $ 10,000 6 CONNECTION TO EXISTING STRUCTURE 2 EA $ 500.00 $ 1,000 7 REMOVE PAVEMENT 178 SY $ 20.00 $ 3,556 8 PATCH PAVEMENT 178 SY $ 50.00 $ 8,889 Subtotal $ 146,984 DEWATERING 5% $ 7,349 EROSION & SEDIMENTATION CONTROL 2% (SeeNote3) $ 2,940 TRAFFIC CONTROL 5% (See Note 4) $ 7,349 CONTINGENCY 15% $ 22,048 Subtotal $ 186,670 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 18,667 Construction Subtotal (Rounded) $ 205,000 STATE SALES TAX 9.5% $ 19,475 ENGINEERING /LEGAL/ADMIN 25% $ 51,250 CONSTRUCTION MANAGEMENT 20% $ 41,000 PERMITTING 5% $ 10,250 Project Subtotal (Rounded) $ 327,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 327,000 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order- of-magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual she conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these fact ors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 4 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Gilliam Creek Crossing at 42nd Ave S. (93 -DR08) CHECKED BY: DATE: Amy Carlson (revised 8/30/12) BY: Raymond Chung 3/2/2012 CIP# 99341208 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 REMOVE /ABANDON EXISITNG 36" DIAM. PIPE 94 LF $ 37.00 $ 3,478 2 16' SPAN MULTI -PLATE OPEN BTM ARCH (5' -3" RISE) 116 LF $ 424.00 $ 49,184 3 CIP PIPE ARCH FOUNDATION / FTGS 19 CY $ 457.50 $ 8,648 4 ROCKERY HEADWALL 2 LS $ 15,000.00 $ 30,000 5 TRENCH SAFETY SYSTEMS 2,640 SF $ 3.00 $ 7,920 6 SHORING (SHEET PILE) 0 SF $ 60.00 $ - 7 RESTORE ROADWAY ASPHALT PAVEMENT 123 TONS $ 91.50 $ 11,285 8 UTILITY RELOCATIONS AND TEMPORARY SUPPORT 1 LS $ 50,000.00 $ 50,000 9 TEMPORARY BYPASS 1 LS $ 15,000.00 $ 15,000 10 STREAMBED COBBLES WITHIN CULVERT 224 CY $ 90.00 $ 20,160 11 STREAMBED CHANNEL RECONSTRUCTION (OUTSIDE CULVERT) 80 LF $ 300.00 $ 24,000 12 ROADWAY EXCAVATION INCL. HAUL 2,712 CY $ 27.00 $ 73,211 13 IMPORTED GRAVEL BACKFILL 1,156 CY $ 40.00 $ 46,230 14 CLEARING AND GRUBBING 1 LS $ 6,000.00 $ 6,000 15 LANDSCAPE RESTORATION 1 LS $ 20,000.00 $ 20,000 Subtotal $ 365,116 DEWATERING $ 10,000 EROSION & SEDIMENTATION CONTROL 5% (See Note 3) $ 18,256 TRAFFIC CONTROL 4% (See Note 4) $ 14,605 CONTINGENCY 10% $ 36,512 Subtotal $ 444,488 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 44,449 Construction Subtotal (Rounded) $ 489,000 STATE SALES TAX 9.5% $ 46,455 ENGINEERING /LEGAL/ADMIN 18% $ 88,020 CONSTRUCTION MANAGEMENT 10% $ 48,900 PERMITTING 6% $ 29,340 Project Subtotal (Rounded) $ 702,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 702,000 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. N does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. Asa result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increased percentage markup because work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increased percentage markup because will require temporary partial, or entire, closure of 42nd. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 5 of 20 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above Because of these factors, funding needs for individual projects must be scrutinized prior to establishingthefinal project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs. 6 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Soil Reclaimation Facility CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP# 99441202 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 RECLAIMATION FACILITY (bid item provided by City) 1 LS $ 760,000.00 $ 1,104,000 2 LF $ - 3 HR $ - 4 EA $ - 5 LS $ - 6 LS $ Subtotal $ 1,104,000 DEWATERING 5% $ 55,200 EROSION & SEDIMENTATION CONTROL 5% (SeeNote3) $ 55,200 TRAFFIC CONTROL 5% (See Note 4) $ 55,200 CONTINGENCY 15% $ 165,600 Subtotal $ 1,435,200 MOBILIZATION (GENERAL REQUIREMENT) 5% $ 71,760 Construction Subtotal (Rounded) $ 1,507,000 STATE SALES TAX 9.5% $ 143,165 ENGINEERING /LEGAL/ADMIN 25% $ 376,750 CONSTRUCTION MANAGEMENT 20% $ 301,400 PERMITTING 5% $ 75,350 Project Subtotal (Rounded) $ 2,404,000 LAND ACQUISITION 2 AC $ 500,000.00 $ 1,000,000 CONTINGENCY 10% $ 100,000 2012 Dollars Total Estimated Project Cost (Rounded) $ 3,504,000 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above Because of these factors, funding needs for individual projects must be scrutinized prior to establishingthefinal project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs. 6 of 20 Notes: • 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not includefuture escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors. funding needs for individual projects must be scrutinized prior to establishing the final project bud gets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 7 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: BY: Northwest Gilliam Storm Drainage System CHECKED BY: DATE: Amy Carlson Raymond Chung 3/2/2012 CIP# 90341206 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 REMOVE /ABANDON PIPE 2096 LF $ 23.00 $ 48,208 2 REMOVE /ABANDON CATCH BASIN 20 EA $ 345.00 $ 6,900 3 PAVEMENT OVERLAY, ASPHALT CONCRETE CL B {QTY > 500) 1446 TN $ 63.00 $ 91,098 4 CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) 7,584 LF $ 9.00 $ 68,256 5 CATCH BASIN TYPE 1 36 EA $ 1,532.00 $ 55,152 6 8" -12" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 4,340 LF $ 81.00 $ 351,540 7 TRENCH SAFETY SYSTEMS 26,040 SF $ 1.00 $ 26,040 8 STORMCEPTOR WQ MANHOLE (STC 2400) 0 EA $ 37,000.00 $ - 9 STORMCEPTOR WQ MANHOLE (STC 4800) 2 EA $ 53,000.00 $ 106,000 10 STORMCEPTOR WQ MANHOLE (STC 7200) 1 EA $ 71,072.00 $ 71,072 11 UTILITY RELOCATIONS 1 LS $ 57,582.00 $ 57,582 12 TEMPORARY BYPASS 1 LS $ 5,758.00 $ 5,758 Subtotal $ 887,606 DEWATERING 5% $ 44,380 EROSION & SEDIMENTATION CONTROL 2% (See Note 3) $ 17,752 TRAFFIC CONTROL 5% (See Note 4) $ 44,380 CONTINGENCY 15% $ 133,141 Subtotal $ 1,127,260 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 112,726 Construction Subtotal (Rounded) $ 1,240,000 STATE SALES TAX 9.5% $ 117,800 ENGINEERING /LEGAL/ADMIN 25% $ 310,000 CONSTRUCTION MANAGEMENT 20% $ 248,000 PERMITTING 5% $ 62,000 Project Subtotal (Rounded) $ 1,978,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 1,978,000 Notes: • 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not includefuture escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors. funding needs for individual projects must be scrutinized prior to establishing the final project bud gets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 7 of 20 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual proiects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: 53rd Avenue 5. Storm Drain System CHECKED BY: Amy Carlson BY: Raymond Chung DATE 3/2/2012 CIP# 90341213 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 CATCH BASIN TYPE 1 18 EA $ 1,532.00 $ 27,576 2 CATCH BASIN TYPE 2 48 " -54" 6 EA $ 4,353.00 $ 26,118 3 CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) 4400 LF $ 9.00 $ 39,600 4 TRENCH SAFETY SYSTEMS 15,360 SF $ 1.00 $ 15,360 5 STORMCEPTOR WQ MANHOLE (STC 2400) 1 EA $ 37,000.00 $ 37,000 6 BIOSWALE CONSTRUCTION (INCLUDES EXCAVATION GRADING AND SEEDING) 8,184 SF $ 6.00 $ 49,104 7 PAVEMENT OVERLAY, ASPHALT CONCRETE CL B {QTY > 500} 1,933 TN $ 63.00 $ 121,779 8 8" -12" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 1,460 LF $ 93.00 $ 135,780 9 18 " -24" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 1,100 LF $ 162.00 $ 178,200 10 REMOVE /ABANDON PIPE 2,200 LF $ 23.00 $ 50,600 11 UTILITY RELOCATIONS 1 LS $ 17,275.00 $ 17,275 Subtotal $ 698,392 DEWATERING 5% $ 34,920 EROSION & SEDIMENTATION CONTROL 2% (See Note 3) $ 13,968 TRAFFIC CONTROL 5% (See Note 4) $ 34,920 CONTINGENCY 15% $ 104,759 Subtotal $ 886,958 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 88,696 2% Construction Subtotal (Rounded) $ 976,000 STATE SALES TAX 9.5% $ 92,720 ENGINEERING /LEGAL/ADMIN 25% $ 244,000 CONSTRUCTION MANAGEMENT 20% $ 195,200 PERMITTING 5% $ 48,800 Project Subtotal (Rounded) $ 1,557,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 1,557,000 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual proiects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. of 20 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. it does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects most be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high- volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 9 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: S. 146th Street Pipe and 35th Avenue S. Drainage System CHECKED BY Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP# 90341214 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 REMOVE /ABANDON PIPE 1,000 LF $ 23.00 $ 23,000 2 REMOVE /ABANDON CATCH BASIN 5 EA $ 345.00 $ 1,725 3 PAVEMENT OVERLAY, ASPHALT CONCRETE CL B {QTY> 500} 1,062 TN $ 63.00 $ 66,906 4 CURB, EXTRUDED (ASPHALT OR CEMENT CONCRETE) 2,700 LF $ 9.00 $ 24,300 5 8" - 12" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREAS 560 LF $ 93.00 $ 52,080 6 18" -24" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 1,050 LF $ 162.00 $ 170,100 7 TRENCH SAFETY SYSTEMS 9,660 SF $ 1.00 $ 9,660 8 CATCH BASIN TYPE 2 48 " -54" 5 EA $ 4,353.00 $ 21,765 9 UTILITY RELOCATIONS 1 LS $ 11,516.00 $ 11,516 10 TEMPORARY BYPASS 1 LS $ 5,758.00 $ 5,758 Subtotal $ 386,810 DEWATERING 5% $ 19,341 EROSION & SEDIMENTATION CONTROL 5% (See Note 3) $ 19,341 TRAFFIC CONTROL 5% (See Note 4) $ 19,341 CONTINGENCY 15% $ 58,022 Subtotal $ 502,853 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 50,285 Construction Subtotal (Rounded) $ 553,000 STATE SALES TAX 9.5% $ 52,535 ENGINEERING /LEGAL /ADMIN 25% $ 138,250 CONSTRUCTION MANAGEMENT 20% $ 110,600 PERMITTING 5% $ 27,650 Project Subtotal (Rounded) $ 882,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 882,000 Notes: 1. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2012 dollars. it does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects most be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high- volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 9 of 20 Notes: 1. The above cost opinion is in 2012 dollars based on information provided by PACE Engineers, and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to Bowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 10 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Storm Lift Station No. 15 Improvement CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP# 91041203 ITEM NO. 1 BID ITEM 1 QUANTITY UNIT 1 UNIT PRICE 1 AMOUNT 1 Generator with Turning Vane 1 Ls $ 220,000.00 $ 220,000 2 Generator Enclosure 1 LS $ 75,000.00 $ 75,000 3 Electrical /Communication 1 LS $ 75,000.00 $ 90,000 4 Concrete Pad 1 LS $ 3,000.00 $ 3,000 5 Asphalt Patch, 2" 30 SY $ 45.00 $ 1,350 6 Crushed Surfacing Top Course 35 TN $ 30.00 $ 1,050 7 Trench Shoring and Protection 1 LS $ 500.00 $ 500 8 Landscape Restoration 1 L5 $ 1,250.00 $ 1,250 Subtotal $ 392,150 DEWATERING $ - EROSION & SEDIMENTATION CONTROL $ 2,000 TRAFFIC CONTROL $ - CONTINGENCY $ 48,000 Subtotal $ 442,150 MOBILIZATION (GENERAL REQUIREMENT) $ 25,000 Construction Subtotal (Rounded) $ 467,000 STATE SALES TAX 9.5% $ 44,365 ENGINEERING /LEGAL/ADMIN 15% $ 70,050 CONSTRUCTION MANAGEMENT 20% $ 93,400 PERMITTING 5% $ 23,350 Project Subtotal (Rounded) $ 698,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 698,000 Notes: 1. The above cost opinion is in 2012 dollars based on information provided by PACE Engineers, and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to Bowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 10 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: East Marginal Wy S Stormwater Outfall CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP4 91041204 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE ] AMOUNT Cost estimate from GHD report for the 'Z-line' outfall 1 REMOVE MANHOLE 4 EA $ 650.00 $ 2,600 2 REMOVE /ABANDON PIPE 980 LF $ 20.00 $ 19,600 3 MANHOLE TYPE 204A 4 EA $ 3,400.00 $ 13,600 4 PIPE, P5, CONC REINF C76 CL 111, 18 IN (TRUNK) 980 LF $ 85.00 $ 83,300 5 SHORING 9,506 SF $ 1.42 $ 13,499 6 BEDDING, CL B, 18" PIPE 980 LF $ 18.00 $ 17,640 7 CONSTRUCTION GEOTEXTILE 1,206 SY $ 2.00 $ 2,412 8 REPAIR CB PIPE CONNECTIONS 6 EA $ 600.00 $ 3,600 9 PIPE, P5, CONC REINF C76 CL III, 18 IN (OUTFALL) 230 LF $ 85.00 $ 19,550 10 8X11 MANHOLE FILTER SYSEM (24 CARTRIDGES) 1 EA $ 50,200.00 $ 50,200 11 VORTECHS 1 EA $ 14,500.00 $ 14,500 12 SAW CUT CEMENT CONCRETE, FULL DEPTH 1,960 IF $ 8.00 $ 15,680 13 REMOVE PAVEMENT 436 SY $ 24.00 $ 10,464 14 CONCRETE PAVEMENT CL6.5, (1 -1/2), 91N 436 SY $ 80.00 $ 34,880 Subtotal $ 301,525 DEWATERING $ - EROSION & SEDIMENTATION CONTROL $ 29,720 TRAFFIC CONTROL $ 14,860 CONTINGENCY $ 92,875 Subtotal $ 438,979 MOBILIZATION (GENERAL REQUIREMENT) $ 29,720 Construction Subtotal (Rounded) $ 469,000 STATE SALES TAX 9.5% $ 44,555 ENGINEERING /LEGAL/ADMIN 30% $ 140,700 CONSTRUCTION MANAGEMENT 20% $ 93,800 PERMITTING 5% $ 23,450 Project Subtotal (Rounded) $ 772,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 772,000 Notes: 1. The above cost opinion is in 2012 dollars based on information provided by GHD, and does not include future escalation, financing, or 0 &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and othervariable factors. As a result, the final project costs will vary from those presented above Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 11 of 20 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or 0 &M costs. 2. The order -of- magnitude cast opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 12 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Water Quality Retrofit Program CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP: 91241201 ITEM NO I BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT S 122th Street 1 STORMCEPTORSTC2400 1 - EA $ 37,000.00 $ 37,000 2 STORMCEPTOR STC 4800 1 EA $ 53,000.00 $ 53,000 3 CATCH BASIN TYPE 1 2 EA $ 1,530.00 $ 3,060 4 CATCH BASIN TYPE 248 " -54" 2 EA $ 4,350.00 $ 8,700 5 18 " -24" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 200 LF $ 141.00 $ 28,200 6 PAVEMENT, HMA CLASS 36 TN $ 150.00 $ 5,396 7 TRENCH SAFETY SYSTEM 1,465 SF $ 1.00 $ 1,465 8 BIOFILTRATION SWALE 200 IF $ - $ - 48th Avenue S 7 STORMCEPTOR STC 11000 1 EA $ 89,000.00 $ 89,000 8 CATCH BASIN TYPE 248 " -54" 2 EA $ 4,350.00 $ 8,700 9 18 " -24" DIA. SMOOTH INTERIOR WALL CORROGATED POLYETHENE IN PAVED AREA 10D LF $ 141.00 $ 14,100 10 PAVEMENT, HMA CLASS 13 TN $ 100.00 $ 1,326 11 TRENCH SAFETY SYSTEM 90D SF $ 1.00 $ 900 $ 250,847 DEWATERING 5% $ 12,542 EROSION & SEDIMENTATION CONTROL 5% (See Note 3) $ 12,542 TRAFFIC CONTROL 5% (See Note 4) $ 12,542 CONTINGENCY 15% $ 37,627 $ 326,101 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 32,610 $ 359,000 STATE SALES TAX 9.5% $ 34,105 ENGINEERING /LEGAL/ADMIN 25% $ 89,750 CONSTRUCTION MANAGEMENT 20% $ 71,800 PERMITTING 5% $ 17,950 $ 573,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 573,000 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or 0 &M costs. 2. The order -of- magnitude cast opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 12 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Tukwila Pkwy /Gilliam Creek Outfalls CHECKED BY: Amy Carlson (revised 8/30/12) BY: Raymond Chung DATE: 3/2/2012 CIP# 91241202 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 SHEETPIPE SHORING, WALERS, BRACING 1,600 SF $ 10.00 $ 16,000 2 MANHOLE TYPE 2, 84- INCHES DIAM. 1 EA $ 14,108.00 $ 14,108 3 MANHOLE TYPE 2, 72- INCHES DIAM. 1 EA $ 10,000.00 $ 10,000 4 REMOVE PAVEMENT 197 SY $ 15.00 $ 2,958 5 PATCH PAVEMENT 197 SY $ 45.00 $ 8,875 6 OVERLAY PAVEMENT & STRIPING 300 SY $ 20.00 $ 6,000 6 SELF- REGULATING TIDE GATE WITH DISCHARGE PORT 1 IS $ 30,000.00 $ 30,000 FOR 84 -INCH DIAM MANHOLE 7 SELF - REGULATING TIDE GATE WITH DISCHARGE PORT 1 LS $ 20,000.00 $ 20,000 FOR 72 -INCH DIAM MANHOLE 8 UTILITY COORDINATION 1 L5 $ 5,000.00 $ 5,000 Subtotal $ 112,941 DEWATERING 10% $ 11,294 EROSION & SEDIMENTATION CONTROL 10% (See Note3) $ 11,294 TRAFFIC CONTROL 15% (See Note 4) $ 16,941 CONTINGENCY 10% $ 11,294 Subtotal $ 163,765 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 16,376 Construction Subtotal (Rounded) $ 180,000 STATE SALES TAX 9.5% $ 17,100 ENGINEERING /LEGAL /ADMIN 20% $ 36,000 CONSTRUCTION MANAGEMENT 15% $ 27,000 PERMITTING 10% $ 18,000 Project Subtotal (Rounded) $ 278,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 278,000 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project Costs will vary from those presented above. Because of these factors, funding needs for individual projects must 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 13 of 20 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O&M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 14 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Tukwila Urban Center Conveyance Inspections CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIP# 91241203 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 PIIPE CLEANING AND CCTV 14,300 LF $ 9.50 $ 135,850 2 DISPOSAL OF SEDIMENT 2,000 TON $ 85.00 $ 170,000 Subtotal $ 305,850 DEWATERING 5% $ 15,293 EROSION & SEDIMENTATION CONTROL 2% (See Note 3) $ 6,117 TRAFFIC CONTROL 5% (See Note 4) $ 15,293 CONTINGENCY 15% $ 45,878 Subtotal $ 388,430 MOBILIZATION (GENERAL REQUIREMENT) 2% $ 7,769 Construction Subtotal (Rounded) $ 396,000 STATE SALES TAX 9.5% $ 37,620 ENGINEERING /LEGAL/ADMIN 2% $ 7,920 CONSTRUCTION MANAGEMENT 20% $ 79,200 PERMITTING 5% $ 19,800 Project Subtotal (Rounded) $ 541,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 541,000 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O&M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 14 of 20 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 15 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: E. Marginal Way Conveyance Inspection CHECKED BY: Amy Carlson BY: Raymond Chung DATE: 3/2/2012 CIPN 91241204 ITEM NO. I BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 PIIPE CLEANING AND CCTV 3,500 LF $ 9.50 $ 33,250 2 DISPOSAL OF SEDIMENT 94 TON $ 85.00 $ 7,969 3 $ - 4 $ - 5 $ - 6 $ - 7 $ - 8 $ - 9 $ - 10 $ - Subtotal $ 41,219 DEWATERING 10% $ 4,122 EROSION & SEDIMENTATION CONTROL 2% (See Note 3) $ 824 TRAFFIC CONTROL 5% (See Note 4) $ 2,061 CONTINGENCY 15% $ 6,183 Subtotal $ 54,409 MOBILIZATION (GENERAL REQUIREMENT) 5% $ 2,720 Construction Subtotal (Rounded) $ 57,000 STATE SALES TAX 9.5% $ 5,415 ENGINEERING /LEGAL/ADMIN 15% $ 8,550 CONSTRUCTION MANAGEMENT 20% $ 11,400 PERMITTING 5% $ 2,850 Project Subtotal (Rounded) $ 85,000 LAND ACQUISITION 0 $ - CONTINGENCY 30% $ - 2012 Dollars Total Estimated Project Cost (Rounded) $ 85,000 Notes: 1. The above cost opinion is in 2012 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 15 of 20 2012 - 2017 0 m SUMMARY OF FUND # 0 z O G N O 00 C h CO J b d- 0) C NOTE: All sheets are linked to the Summary SURFACE WATER Q To v o .o a N C O A � O C O u PROJECT TITLE 0 rc 6 New Estimate a 0 Under design (75% completion). Cost provided by the City Updated from 2003 0 0 0 0 o °0 0 00 m o te LS O a, W ti M O 0 0 0 0 0 O • 0 O 0 0 00 0 00 v Nelson Salmon Habitat Side Channel Duwamish Gardens Riverton Creek Flap Gate Removal Gilliam Creek Fish Barrier Removal 0 0 0 • LO 0 0 ▪ O 0 0 K) CO CO CO m u0 CO CO 0 0 00 CO CO CO m m 2012 - 2017 Capital Improvement Program Notes: 1. The above cost opinion is in 2011 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 17 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Nelson Salmon Habitat Side Channel CHECKED BY: BY: Raymond Chung DATE: 3/1/2012 CIP# 90330104 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 COMMON EXCAVATION (INCL HAUL) 13600 CY $ 10.00 $ 136,000 2 VINYL SHEET PILES (EXPOSED FACE AREA) 3,120 SF $ 40.00 $ 124,800 3 PILING CONTRACTOR MOB /DEMOB 1 LS $ 10,000.00 $ 10,000 4 EMBANKMENT COMPACTION 900 CY $ 5.00 $ 4,500 5 BOULDERS /RIPRAP, SLOPE PROTECTION 200 CY $ 50.00 $ 10,000 6 GEOTEX TILE UNDER RIPRAP 274 SY $ 2.00 $ 548 7 PLANTING 0.7 AC $ 20,000.00 $ 14,000 8 COMMON BORROW INSIDE SHEETS 415 CY $ 15.00 $ 6,225 9 CLEARING AND GRUBBING 0.5 AC $ 8,000.00 $ 4,000 10 SET & REMOVE COFFERDAM 250 LF $ 500.00 $ 125,000 11 TREE SCREEN ON SOUTH SIDE OF WALLS 430 LF $ 50.00 $ 21,500 12 SLAB TOP ON WALL STRUCTURE 42 CY $ 300.00 $ 12,613 13 SAFETY RAILINGS 860 LF $ 40.00 $ 34,400 14 LARGE WOODY DEBRIS 1 LS $ 50,000.00 $ 50,000 Subtotal $ 553,586 DEWATERING 5% $ 27,679 EROSION & SEDIMENTATION CONTROL 20% (See Note 3) $ 110,717 TRAFFIC CONTROL 5% (See Note 4) $ 27,679 CONTINGENCY 15% $ 83,038 Subtotal $ 802,700 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 80,270 Construction Subtotal (Rounded) $ 883,000 STATE SALES TAX 9.5% $ 83,885 ENGINEERING /LEGAL /ADMIN 30% $ 264,900 CONSTRUCTION MANAGEMENT 20% $ 176,600 PERMITTING 10% $ 88,300 Project Subtotal (Rounded) $ 1,497,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 15% $ - 2011 Dollars Total Estimated Project Cost (Rounded) $ 1,497,000 Notes: 1. The above cost opinion is in 2011 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 17 of 20 Notes: 1. The above cost opinion is in 2011 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 18 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Duwamish Gardens CHECKED BY: BY: Raymond Chung DATE: 3/2/2012 CIP4t 90630102 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 Restoration 1 LS $ 3,000,000.00 $ 3,000,000 2 $ - 3 $ - 4 5 6 Subtotal $ 3,000,000 DEWATERING $ - EROSION & SEDIMENTATION CONTROL (See Note 3) $ - TRAFFIC CONTROL (See Note 4) $ - CONTINGENCY $ - Subtotal $ 3,000,000 MOBILIZATION (GENERAL REQUIREMENT) $ - Construction Subtotal (Rounded) $ 3,000,000 STATE SALES TAX $ - ENGINEERING/LEGAL/ADMIN $ - CONSTRUCTION MANAGEMENT $ - PERMITTING $ - Project Subtotal (Rounded) $ 3,000,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 15% $ - 2011 Dollars Total Estimated Project Cost (Rounded) $ 3,000,000 Notes: 1. The above cost opinion is in 2011 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 18 of 20 Notes: 1. The above cost opinion is in 2011 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 19 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Riverton Creek Flap Gate Removal CHECKED BY: BY: Raymond Chung DATE: 3/2/2012 CIP# 99830103 ITEM NO. 1 BID ITEM 1 QUANTITY UNIT 1 UNIT PRICE I AMOUNT 1 CLEAR AND GRUBBING, REMOVAL AND DEMOINATION 1 LS $ 17,925 $ 17,925 2 DITCH EXCAVATION INCLUDING HAUL 1,125 CY $ 50 $ 56,250 3 TIE -BACK ANCHORS, 20 FT, THROUGH SHEET PILE WALL 10 EA $ 8,500 $ 85,000 4 CLEANING AND 5/16" FILLET WIELD OF SHEET PILES TO WALL CAP 10 EA $ 200 $ 2,000 5 EPDXY DOW ELLS AT WALL CAP 50 LS $ 35 $ 1,750 6 CONCRETE WALL CAP 16 CY $ 150 $ 2,400 7 8 -INCH DIAM. STANDARD PIPE MICROPILE 280 LF $ 50 $ 14,000 8 BRIDGE ABUTMENT CONCRETE 20 CY $ 500 $ 10,000 9 MODULAR BLOCK RETAINING WALL 1 LS $ 5,000 $ 5,000 10 PREFABRICATED BRIDGE 1 LS $ 50,000 $ 50,000 11 HOT MIX ASPHALT WITH CSBC 1 TON $ 160 $ 160 12 LARGE WOODY DEBRIS 11 EA $ 11,000 $ 121,000 13 OVERLAPPED LARGE WOODY DEBRIS 2 EA $ 4,000 $ 8,000 14 PLANTING 1 LS $ 6,000 $ 6,000 15 SURVEY 1 LS $ 7,500 $ 7,500 Subtotal $ 386,985 DEWATERING 5% $ 19,349 EROSION & SEDIMENTATION CONTROL 10% (See Note 3) $ 38,699 TRAFFIC CONTROL 5% (See Note 4) $ 19,349 CONTINGENCY 15% $ 58,048 Subtotal $ 522,430 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 52,243 Construction Subtotal (Rounded) $ 575,000 STATE SALES TAX 9.5% $ 54,625 ENGINEERING /LEGAL /ADMIN 25% $ 143,750 CONSTRUCTION MANAGEMENT 20% $ 115,000 PERMITTING 10% $ 57,500 Project Subtotal (Rounded) $ 946,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 15% $ - 2011 Dollars Total Estimated Project Cost (Rounded) $ 946,000 Notes: 1. The above cost opinion is in 2011 dollars and does not include future escalation, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects must be scrutinized prior to establishing the final project budgets. 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 19 of 20 Notes: 1.. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2011 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 20 of 20 PLANNING LEVEL CONSTRUCTION COST OPINION PROJECT: Gilliam Creek Fish Barrier Removal CHECKED BY: BY: Raymond Chung DATE: 3/2/2012 CIP# 99830105 ITEM NO. 1 BID ITEM 1 QUANTITY 1 UNIT 1 UNIT PRICE 1 AMOUNT 1 CLEARING AND GRUBBING, AND ROADSIDE CLEANUP 1 AC $ 9,213 $ 9,213 2 COMMON EXCAVATION 30 CY $ 31 $ 933 3 TOP SOIL 130 CY $ 32 $ 4,192 4 PLANTING (WETLAND ENHANCEMENT) 1 LS $ 23,033 $ 23,033 5 EMBANKMENT COMPACTION 20 CY $ 25 $ 507 6 GRAVEL CLASS B 75 TN $ 25 $ 1,900 7 STREAMBED GRAVEL 35 TN $ 35 $ 1,209 8 RIPRAP 3,200 TN $ 52 $ 165,837 9 CONCRETE CLASS A (INCL. FORMS AND REBAR) 110 CY $ 633 $ 69,675 10 108" SELF - REGULATING TIDE GATE 1 EA $ 57,582 $ 57,582 Subtotal $ 334,081 DEWATERING 5% $ 16,704 EROSION & SEDIMENTATION CONTROL 10% (See Note 3) $ 33,408 TRAFFIC CONTROL 5% (See Note 4) $ 16,704 CONTINGENCY 15% $ 50,112 Subtotal $ 451,009 MOBILIZATION (GENERAL REQUIREMENT) 10% $ 45,101 Construction Subtotal (Rounded) $ 496,000 STATE SALES TAX 9.5% $ 47,120 ENGINEERING /LEGAL /ADMIN 25% $ 124,000 CONSTRUCTION MANAGEMENT 20% $ 99,200 PERMITTING 10% $ 49,600 Project Subtotal (Rounded) $ 816,000 LAND ACQUISITION 0 AC $ - CONTINGENCY 15% $ - 2011 Dollars Total Estimated Project Cost (Rounded) $ 816,000 Notes: 1.. The above cost opinion is based on 2003 quantities, with unit prices escalated to 2011 dollars. It does not include future escalation beyond 2011, financing, or O &M costs. 2. The order -of- magnitude cost opinion has been prepared for guidance in project evaluation from the information available at the time of preparation and for the assumptions stated. The final costs of the project will depend on actual labor and material costs, actual site conditions, productivity, competitive market conditions, final project scope and schedule, and other variable factors. As a result, the final project costs will vary from those presented above. Because of these factors, funding needs for individual projects 3. Increase percentage markup if work is in or immediately adjacent to flowing or standing water, steep slope, and /or other erosion -prone conditions. 4. Increase percentage markup if work is in or immediately adjacent to secondary, arterial, or other high - volume road or temporarily closes a roadway. 5. Land Acquisition unit costs include Administrative Costs and Condemnation. 20 of 20