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HomeMy WebLinkAboutSEPA EPIC-SA-1 - SOUTH AREA PARK AND ATHLETIC FACILITY (FORT DENT)SOUTH AREA PARK AND ATHLETIC FACILITY DEIS (FORT DENT) EPIC -SA -1 King County State of Washington John D. Spellman, County Executive Department of Community and Environmental Development Thomas M. Ryan, Director March 8, 1974 Tukwila Planning Commission 14475 59th Ave. South Tukwila 98067 Re: South Area Park and Athletic Facility Draft Environmental Impact Statement Gentlemen: Architecture Division 1221 Smith Tower Seattle, Washington 98104 GERALD R. SCHLATTER, AIA /AIP, Manager 206 - 344 -5222 Please find enclosed one copy of the Draft Environmental Impact Statement prepared for the above referenced project. This state- ment has been prepared and is being circulated for your information and comment, pursuant to the Washington State Environmental Policy Act of 1.971 and King County Ordinance 1700. Sincerely, COMMUNITY DEVELOPMENT /ARCHITECTURE DIVISION z 441 Paul D. Leland PDL:kjr Enclosure • FIRE DEPARTMENT • CITY or TUKWILA Frank Todd, Mayor 5900 SO. 147TH ST. TUKWILA, WASHINGTON 98067 Fire Prevention Bureau March 21, 1974 Mr. Gary Crutchfield Planning Department City of Tukwila Dear Mr. Crutchfield: Re: South Area Park Environmental Impact Statement.(Draft). In reviewing this statement, I have noticed the follow- ing items: In a previous meeting with officials regarding this project, several items were discussed, including fire hydrants, emergency vehicle access and maneuvering lanes, emergency telephone and alarm facilities. These items are not mentioned in this document and should be resolved at the earliest possible date. JH :vma cc: T.F.D. file James Hoel Fire Marshal • Frank Todd, Mayor CiTY ®F TUK 'IL 6230 SOUTHCENTER BLVD. TUKWILA, WASHINGTON 98067 PLANNING DEPARTMENT King County Architecture Division ATTN: Mr. Paul D. Leland ' 1221 Smith Tower Seattle, Washington 98104 RE: Environmental Impact Statement- - South Area Park Dear Mr. Leland: 12 April 1974 This office has reviewed tWe above referenced Impact Statement in accordance with the State Environmental Policy Act. Although some minor points remain, unclear, such as emergency vehicle access, we feel certain they can be resolved at some future date. Overall, the City of Tukwila has no significant comment to offer regarding the Environmental Impact Statement. GC/lt. cc: Ping Dir Sincerely, Gary /Crutchfiel Planning Technician South Area Park and Athletic Facility IDKAF'f ENVIRONMENTAL IMPACT STATEMENT MARCH, 1974 DRAFT ENVIRONMENTAL IMPACT STATEMENT SOUTH AREA PARK AND ATHLETIC FACILITY Architecture. Division Department of Community and Environmental Development King County, Washington Prepared pursuant to the Washington State Environmental Policy Act of 1971 (Chapter 43.21c R.C.W.) Circulation Period: March 13, 1974 through April 13, 1974 Comments or Questions should be addressed to: King County Architecture Division Attention: Paul D. Leland 1221 Smith Tower Seattle, Washington 98104 Phone: 344 -5222 March 1974 Responsible Official: Thoma M. Ryan, Direc Department of Commun Environmental Develo PvlA., r y and men t erald R. Schlatter, Manager 7rchitecture Division CONTENTS. Summary Sheet Recipients of Draft Statement iv PROPOSED ACTION 1. Type of Action 1 2. Justification 1 3. Project Description 3 a. Objectives 3 b. Proposed Master Plan Program 3 c. Principal Design Concepts /Principles 11 d. Project Location 12 4. Project Overview 12 a. Historical Background 12 b. Site Selection and Acquisition 16 c. Financing 20 d. Citizen Participation 20 5. Relationship with Existing Laws, Policies, Plans 21 a. Permits Required 21 b. Conformance with Plans /Policies 22 c. Actions /Decisions Remaining Prior to Implementation 23 EXISTING CONDITIONS 26 1. Natural Setting 26 a. Physiographic Setting and Features 26 b. Geology 27 c. Soils 27 d. Habitats 28 _e. Hydrology /Drainage 31 2.. Human Environment 32 a. Land Use 32 b. Activity Nodes 38 c. Transportation Systems 38 d. Utilities 41 e. Pollutants 42 4 ENVIRONMENTAL IMPACT. 45 1. Natural Environment 45 a. Site Geology /Topography /Soils 45 b. Natural Habitats 45 c. Hydrology 46 2. Human Environment /Values 50 a. Traffic 50 b. Land Use 55 c. Resultant Pollutants 58 d. Resource Commitments 60 UNAVOIDABLE ADVERSE IMPACTS /MITIGATING MEASURES 64 1. Natural Environment 64 2. Human Environment Values 65 ALTERNATIVES TO THE PROPOSED ACTION 66 1. Delete Project 66 2. Alternative Sites 68 3. Alternative Site Programs 70 4. Vehicular Access and Parking 71 RELATIONSHIP BETWEEN SHORT TERM ENVIRONMENTAL USES AND ENHANCEMENT OF ENVIRONMENTAL PRODUCTIVITY 77 IRREVERSIBLE OR IRRETRIEVABLE RESOURCE COMMITMENTS 78 SUMMARY Nature of Report: Draft Environmental Impact Statement Lead Agency: Sponsoring Agency: Managing Agency: Contact: King County Department of Community and Environmental Development. Tom Ryan, Director (Responsible. Official) King County Department of Community and Environmental Development, Parks and Rec- reation Di:ySi:on, George Wyse, gana9ez Room W -226, King County Courthouse Seattle, Washington 98104 King County Department of Community and Environmental Development, Architecture Division. Gerald Schlatter, Manager 1221 Smith Tower Seattle, Washington 98104 Paul D. Leland, Planner Architecture Division 1221 Smith Tower Seattle, Washington 98104 Phone: 344 -5222 Type of Proposed Action: Planning and development (construction) of the South Area Park and Athletic Facility adjacent to the Green. River north of Interstate 405 in Tukwila. A master plan has been prepared covering two anticipated development phases -- only one of which is currently funded and scheduled for construction during 1974. This environmental impact statement addresses both develop - ment phases of the project Official Action Covered by this Statement: Permits 1. Substantial Development Permit (Tukwila) 2. Coast Guard Permit approving plans for construction of a bridge over navigable water ii 3. Hydraulic Permit (Washington State Department of Fisheries and Game) 4. Flood Control Zone Permit (Washington State Department of Ecology) 5. Building Permits 6. Sewer and Water Permits Summary of Significant Environmental Impacts: a. Topography /Soils: The site topography will be altered to construct athletic fields, earth mounds stadium seating areas, and a perimeter flood control berm. Approximately 50,000 cubic yards of fill will be imported onto the site. b. Biological Impact: The existing vegetative and wildlife habitat of the site will be substantially altered, with reductions in some species of wildlife and gains in others. c. Hydrological and Water Quality Impact: The effective floodplain of the Green River will be marginally reduced as a result of perimeter diking of the site. Surface run -off will be somewhat accelerated with possible in- creases in plant nutrients and petroleum related pollutants entering the on -site retention pond and the Green River. d. Air Quality Impact: Vehicular traffic will contribute to the amounts of carbon monoxide entering the local valley air -shed. Because park related traffic will generally be spread out in time (and generally not coincide with peak traffic conditions) it is not expected to aggravate peak 1 -hour average concentrations of air pollutants. e. Human Environment: 1. Vehicular Traffic: Increased traffic will be gene- rated but it will be dispersed during the day and evening hours, and will generally not coincide with rush hour. traffic. Peak park related traffic may occasionally over- lap with weekend traffic peaks associated with the Longacres race track. 2. Ambient Noise /Visual Impact: On -site noise is not expected to adversely affect adjacent industrial, busi- ness or residential land uses. Ambient noise levels and the distances between the stadium facilities and adjacent residential areas will effectively mitigate any potential audio impacts. Some night time 'spill- light' from the athletic field lights will be visible from adjacent resi- dential areas. Field lights have been designed to maximize lighting efficiency and hence minimize spill- light. iii Summary of Alternatives: a. The 'Do- nothing' alternative: Deletion of the proposed project was considered unacceptable, due to the on -going impact which would accrue in terms of overutilization of existing neighborhood and community athletic fields and water- related passive recreational and open space areas. b. A series of alternative sites were considered several miles to the north of the South Area Park site. Environ- mental impacts associated with-the alternative sites were comparable or worse than anticipated at the Tukwila site. Several of the alternative sites were prime industrial sites fronting on navigable portions of the Duwamish. c. Consideration was directed to alternative project emphasis priorities with respect to formal athletic fields and facilities versus more passive recreational and open, space. opportunities. Differences of opinion remain concerning the appropriate emphasis of the park proposal, although the project emphasis, as discussed in this statement, has been found generally acceptable. Both the athletic facili- ties and more passive open space and recreational opportun- ities are high priority needs in . the area. d. A range of vehicular access and parking arrangements were considered as a part of the design development of the project. Off -site parking has been rejected as too costly in terms of convenience, emerging vehicular access, and construction /acquisition costs, relative to the gains which would accrue in terms of on -site space and amenities.. Vehicular access from the east of the site was rejected as too inconvenient, hazardous and costly in terms of minimal . levels of roadway improvement required. . iv "RECIPIENTS OF DRAFT STATEMENT State of Washington: Department of Ecology .Department of Game Department of Fisheries Highway Department (District #7) Parks and Recreation Commission Department of Natural Resources. King County: Department of Budget and Program Planning Department of'Community and Environmental Development Department of Public Works Seattle -King County Department of Public Health Federal Agencies: U. S. Department of Agriculture: Soil Conservation Service U. S. Department of Interior: Bureau of Sports Fisheries Environmental Protection Agency Thirteenth Coast Guard District Cities and Towns: City of Renton: Department of Planning City of Seattle: Planning Division Department of Community Development Department of Parks and .Recreation City of Tukwila: Planning Commission Regional Agencies: Puget Sound Governmental Conference Puget Sound Air Pollution Control Agency Municipality of Metropolitan Seattle Newspapers: Renton Record - Chronicle Seattle Times vi Seattle Post Intelligencer Highline Times Local School Districts: Libraries: Renton School District #403 South Central School District #406 Highline School District #401 Foster Library Renton Public Library Burien Library Seattle Public Library Seattle Municipal Reference Library Community Groups: Highline Community Council Highline Recreation Council vii Duwamish Improvement Club Tukwila Chamber of Commerce Tukwila Industrial Council. Environmental Groups: Washington Environmental Council Sierra Club Other Interested Parties: Don Koll Northwest Wilsey & Ham, Incorporated PROPOSED ACTION 1. Type of Action The proposed action entails proceeding with the development of the South Area Park and Athletic. Facility complex. The complex was specified as an element of the overall Forward Thrust Park and Recreational Facilities Bond Proposition placed before the voters of King County and approved in February 1968. King County Resolution 34571: Section 3 I(4): South Area Park and Athletic Field: $3,599,000 Acquisition and development of approxi- mately 70 acres for park and recreational activities including major athletic fields along the Green River north of the Tukwila interchange of the Interstate 5 freeway. (King County) 2. Justification Justification for the development of the park and athletic facility derives from 1) the mandate of the voters of King County as described above, and 2) a site investigation and feasibility study, South Area Park and Athletic Field (October 1968) prepared by David Jensen, Associates. The Jensen study critically evaluated the need for park and recreational facilities in the vicinity of the.Duwamish River Valley, directing attention to current and projected population and employment figures for the valley and vicinity, and the utiliza- tion trends associated with existing parks and athletic facilities. In 1961 total employment in the river valley bounded on the north by Harbor Island and the south by Tukwila, amounted to 92,500 persons. By 1975, it is forecast that nearly 103,000 people will be employed in the same area. While there is relatively little residential development in the valley itself, there are in excess of 150,000 people living in surrounding areas of West Seattle and Rainier Valley. This population, combined with the increasing employment in the area, has generated a demand for recreational and athletic facilities in excess of the capacity of existing neighborhood and community recreational facilities in the area. Existing neigborhood and community athletic field facilities in the vicinity are both limited in number . and not well suited to the intensity of use and associated activities which are characteristic of industrial and commercial athletic league competition. It is contemplated that the proposed facility will be used for industrial and commercial athletic team play, residential athletic competition tchurch groups, scouts, etc.) and to a lesser extent interscholastic competition between secondary schools within the Seattle and Highline School Districts. With more than 4,000 feet of riverfront, South Area Park offers an opportunity to help meet the identified statewide need for more public access to stream banks and waterways. The need for increased access and informal recreational opportunities along water- ways is especially critical along the.Duwamish /Green River waterway much of which has already been pre - empted for commercial and industrial development. 3. Project Description a. Objectives 1. To provide facilities to accommodate a variety of identi- fied structured athletic events. 2. To provide public access to and opportunities for passive recreational enjoyment of the Green River bank and watercourse. 3. To provide a full range of family - oriented recreational activities. 4. To enhance the unique environmental attributes of the site for the enjoyment. of park users. 5. To integrate the park with the proposed King County urban trail system. b. Proposed Master Plan Program The Master Plan (prepared by. Wilsey & Ham, Inc., Renton, Washington) incorporates the following elements:. Phase One (slated for construction in 1974):. 1. Water service, sanitary sewers, power, irrigation, drainage for the entire site. . 2. Vehicular access to the site (by way of a publicly dedicated road from Interurban Avenue to the land parcel situated immediately south and across the Green River from the project site) and a bridge across the Green River. The access road to the center of the site will be a two -lane road and completely separate from the parking lots. The entire length of the road will be planted with street trees to break up the apparent expanse of the site as visitors enter. Trees will also provide background to the open meadow appearance of the west side of the site as it is viewed from across the river. All walks will be a minimum of 8' wide to allow aid car ac- cess throughout the site. 3. Space for Vehicular Parking: Parking is despersed into small areas near major facilities for user's convenience and to conserve large open spaces for other facilities and fields. Based on anticipated, user statistics compiled by the Seattle Parks Department, space for parking approximately 500 cars will be provided. A major parking area will be located at the approximate center of the site adjacent to the administrative center. This parking area is planned to serve facilities at the north end of the site and to serve the stadium complex. Angle parking adjacent to the practice fields will allow some spectator viewing from automobiles. Overflow parking will be accommodated on buffer areas between the practice fields and the parking lots.. Street trees will line the access road and parking lots. 4. Pedestrian Access and Circulation: South Area Park will function as a significant junction between segments of the urban trail system proposed by King County. The park site will function as a resting point with restroon and picnicking 6 facilities available for use by hikers and bicyclists. Pedestrian and bicycle traffic will follow the access road along an 8' wide trail into the park. Once across the river, the trail: will branch, one loop going under the bridge and following the river bank and the other following the vehicular road to the central administrative complex and center of the park. Pedestrian trails will be provided around the entire perimeter of the site. Phase two of the development plans will include a pedestrian - bridge across -the Green-River at the north end of the site. The final location of this bridge will await further clarification of the urban trail corridor north of the park site. 5. Passive Recreational Facilities /Areas: A green buffer area along the river bank (varying in width) will serve as a picnicking and passive recreation area. The sandy point bar at the southwest corner of the site will also serve as a passive recreational area, providing physical access to the watercourse- of the Green River. Fishing will be possible from along the bank. The existing pond on the eastern side of the site will be retained as a retention pond and in- cluded as an element of the overall site landscaping plan. The area immediately west of the pond will include a children's play area and will accommodate additional picnicking activity. The pond currently functions as a wildlife habitat for certain shorebirds and ducks, and the intent is to retain the water surface and edges as a habitat suited for indigenous birdlife. 6. Baseball and Softball Fields in Cloverleaf configuration: A softball cloverleaf will be located at the northwest cor- ner of the site where the curve of the outfield lines will parallel the curve of the river. Two lighted football fields will share lighting facilities with the softball fields. Be- cause of the cloverleaf configuration two of the softball fields will have a less desirable orientation with respect to the sun angle on the playing fields. A buffer area of at least 80' between the base lines of adjacent fields will provide space for seating and circulation during games.. An earth form running in two directions between the four fields will be used for seating and as a base for a restroom / concession structure in the center, which will have a floor elevation 2' above the 100 year flood level. A second level of the building will be provided for, scorekeepers. East pedestrian access to this area will be provided by both ramping and stairs. All of the fields have been designed in accordance with specifi- cations designated for official tournament play. Three of the fields will have 285 foot permanent outfield fences. One field, which will serve as the championship field, will have a 320 foot permanent outfield fence. A permanent 8' high fence will be provided around the entire cloverleaf complex so that ad- mission may be regulated and charged. The entire perimeter fence will be densely planted with trees and shrubs or slatted to provide a background for batters and serve as a noise buffer for passive use areas. 4 Fields 60' Baselines for softball and 90' for baseball 285' Outfield fence on three fields 320' Outfield ' fence on one field Seating for 1000 at the large field and 300 at each of the three smaller fields 1 Restroom /concession building 7. Practice fields including 1 soccer /rugby field, 1 football field, 2 field hockey fields, 2 flag football fields (super- imposed on the three softball fields), and 1 softball field. The majority of the practice fields will be located along the west side of the site. In this configuration the entire west side will remain largely as it currently appears from west of the river and will provide both formal game areas as well as a large open field for informal activities (such as group picnics). The east side of this open area will be planted with a dense buffer of trees to screen the parking area and access road and to provide a visually pleasant background for the view of the river and park from the west (along Interurban Avenue and from the houses along the hillside). Soccer Fields Football Fields Field Hockey 225' x 360' 160' x 360' 180' x 300' 8. Central Administrative /Restroom Complex: A centrally located administrative facility will be situated adjacent to the parking area. This facility will serve as the administrative center of the park, a control point for admission to the stadium com- plex, and as a central public restroom facility for the practice fields and all areas outside of the stadium and cloverleaf complexes. Phase Two (slated for construction whenever a funding source becomes available). 9. .Stadium complex including alighted baseball field, a'soccer/ football /rugby field, a track and field (football) facility, and a central locker room /shower facility. The stadiums and track/ field have been designed in close juxtaposition to enable creation of a common earth form for seating. The two stadiums will each have formal grandstand seating for 2,000 people and will be covered. The slope adjacent to the running track will provide informal seating. The central locker room /shower /restroom and storage complex will be located central to the three athletic facilities within the • earth form with tunnels leading to each facility. The tunnels are designed to enable any given tunnel to be closed off when a particular facility is not being used. Spectators will be able to enter the stands from above the top of the earth form which will serve as a plaza for all three facilities. The earth form and stadium complex will facilitate ease of maintenance and control of admission. Public restrooms and concessions will be provided on the plaza level. 10 Baseball Stadium: 375' center field fence, 325' foul lines 60' between baseline and seating; Seating - 2000 (covered) Soccer/Rugby Stadium: Playing Surface - 240' x 360' 20' between outside line, and seating; 2000 (covered) Track & Field (Football): 440 Yd. (1/4 Mile) Running track with 8 lanes 3 1/2' wide. Inside curve radius 105' min. . Football playing surface 300' x 160' 30' between outside line and track Seating - .Informal Shower /Locker /Restroom Complex: (Facility requirements for football) Dressing Rooms - Locker Room - 60 lockers Shower Room for 30 Toilets — Male & Female Small Office Storage Room 10. Tennis Courts: Six lighted tennis courts will be located in close proximity to the pond and a quiet passive use area. They will also be close to the central administration complex and parking area for ease of control and access. The courts are arranged in groups of two to allow for optimal lighting configura- tions and are oriented north and south. Additionally the groupings will be offset to allow for planting around the courts . for a visual background. Two unlighted courts will be included -_ in Phase One. Tennis Courts= = -6 60' x 120'. 11. Archery Range: An archery range and adjacent buffer areas have been designed to separate the potential hazard of archery activities from the mainstream of park activities. This has been 11 accomplished by using earth berms and extensive tree plantings. The berm and trees will both visually identify the archery area and help to alleviate the strong crosswinds and sun glare. As planned the separation of the archery area from the rest of the site will be both visual and physical. The range is located at the east side of the site away from pedestrian circulation routes and activity centers. The orienta- tion is with the targets toward the south end. Archery Range 120' x 450' 12. Caretaker's House: A caretaker's house will be located near the entrance of the park to control access after closing_ hours. This location will also afford privacy for the residents. .Ten- tatively the house will encompass 1200 - 1600 square feet of f loorspace .` 13. Pedestrian /Bicycle Trail bridge over Green River - on north end of site. c. Principal Design Concepts /Principles Employed: 1. Maintain the openness of the west side of the site. 2. Concentrate both stadiums and the running track so.a common land form can be used for seating. 3. Concentrate lighted facilities away from the west side of the site to reduce glare impact on adjacent Tukwila residential areas. 4. Concentrate lighted facilities so that lighting may be shared. 5. Provide a central administration point for easy identi- fication by visitors and to . facilitate control by park administrators. 12 6. Concentrate formalized activities such as the tennis courts, stadium complex away from practice fields and informal use areas. 7. Provide adequate buffer zones between facilities for maxium use and safety of fields; provide a buffer separation between walks and parking areas. Provide space for tree plantings and possible overflow parking. 8. Provide adequate passive use zone including trail related activities at the site perimeter. . Disperse parking to small areas near major facilities and fields for user convenience and to conserve large open spaces for other facilities and fields. 10. Provide separate living quarters for a caretaker near the park entrance for (a) easy access control when the park is closed, and (b) privacy for the caretaker.. 11. Provide . for physical and visual access to the bank and watercourse of the Green River. 12. Retain natural vegetative habitat to extent feasible along river bank and around edge of pond. d. Location: The project site is situated about 1/2 mile north of the intersection of Interstate 405 and Interurban Avenue in Tukwila, Washington (See Vicinity Map). More specifically, the site is just upstream of the confluence of the Green and Black rivers, on the eastern and inside curve of the Green River. A series of railroad tracks form the east boundary. of the site. The site consists of approximately 51.5 acres of land (measured to mean waterline) and includes about 4,000 feet of riverbank. The site is situated within the following quarter sections: N.E. 1/4 Section 23, Township 23 N., Range 4E and N.W. 1/4 Section 24, Township 23 N., Range 4E. 4. Project Overview: a. Historical Background _. _ - - .- 14 South Area Park has become a joint Forward Thrust project between the City Of Seattle and King County. Initially it was scheduled as an element of the Forward Thrust program specified for the City. At that time the project was conceived of as . almost entirel3 concerned with the provision of athletic playing fields and facilities. The intent of the City was to satisfy the demand for such. facilities stemmingfrom the growth of industrial recrea- tional programs in the southern part of the City (particularly in the Duwamish River Valley and environs). Without additional facilities, the level of demand for such facilities was over -. loading existing community and neighborhood playfields in the southern half of the City. The park was proposed to complement the City's existing athletic fields and facilities north of the Central Business District (the lower Woodland Park athletic fields, Metro stadium etc.). The South Area Park project was transferred to the County portion of the Forward Thrust Parks & Recreation Program, prior to the program being submitted to the voters in 1968. This was done be- cause the anticipated location of the facility was South of the Seattle City limits and was planned to have considerable open space and park impact in the Duwamish /Green River Valley. As such legal constraints necessitated that the project be included within the County portion of the Parks & Recreation Bond Issue. Furthermore, at this same time, the County was directing attention toward the provision of more passive recreational opportunity and open space along the Duwamish and Green River watercourses, 15 enhancing its value as a visual amenity, a potential trail corridor, and as an area for picnicking, fishing, bird watching, berry picking, and related forms of unstructured outdoor recreation. On November 1, 1968 the City of Seattle and King County jointly formalized an agreement concerning the joint development of South Area Park. The principal points of the agreement were specified • as follows: 1. The County and City will cooperate in the selection of the site. 2. The County and City will be equally responsible for approval of the site plans. 3. The County will be responsible for development of the Complex in cooperation with the City. . The County shall be mainly responsible for the operation, maintenance and scheduling of the park portion of the Complex. 5. The City shall be mainly responsible for the operation, maintenance and scheduling of the athletic portion of the Complex. 6. That after the final site selection and general development plans are completed, further agreements setting out in detail the more precise sharing of maintenance and operating costs and /or responsibilities shall be developed in accordance with the general intent of this Agreement. As of February 1974, it is contemplated that the County will enter into an agreement with the City of Seattle, wherein the City of Seattle will operate and maintain not only the athletic facilities, but also the passive recreational areas and facilities the City being reimbursed by the County for the costs of main- taining the passive recreational areas. 16 b. Site Selection /Acquisition.: The City and County jointly sponsored a study "A Study of. South Area Park and Athletic Field," prepared by David Jensen Associates, to identify and analyze a range of potential sites for South Area Park. The study identified and evaluated a field of 6 sites along the Duwamish River, the northern -most sites situated to the west of Boeing field (see Map of Alternative Sites, page 17). Of the range of sites considered, the study recommended that either site #2 or a combination of sites 4 and 4 -S be acquired for development of the proposed facility. The site analysis focused on vehicular access, land use factors (highest and best use of sites; compatibility of adjacent uses and park activities, zoning), soils, physiographic constraints, and development costs. Site 2, while well suited for the park in terms of access, location, and estimated development costs, was dismissed from further consideration because of its prime suitability for industrial development (the site is on a portion of the Duwamish waterway which accommodates barge . traffic r ' is zoned M -Ii Heavy Manufacturing, and designated for Industrial development by the Port of Seattle). Early in 1969, the County and City jointly approved the Riverton Site (a combination of portions of sites 4 and 5 identified in the Jensen report) for development of the proposed Park 'and Athletic Facility Complex. The Riverton site zoned Suburban Residental, encompassed 74 acres (more than enough land to ac- commodate both the athletic fields and passive recreational L--- 11 : : ;1 • : :to =4 • - rp rr:fr 11-11n - _ ••—'• r, „,- • . .1 -,---- vi•„ E. , ,or . • 0 1:•:i,1 _1 • • 17-1 • • • r)~1 '< and ; r r , Fleld Site TD tf.1 rN r\ tr. 1 1 S•,./ •+:› 1.3 • 117 () ( S. W. ROXB 'WHITE V.ENTE •- \ • RAINIER PEA ti %\st,..,%.......-44.4. .r N' .. ........,.., .04 ,.. • ,44.4.i..........- . N's ..4. I K E Y 1 •• . -, ? • ..,-. industrial commercial --- secondary schools / i .- • t.,i3 ------- residential. — —,a44,3,44,41.41f4R71 - ov......m........./.. • AREAS • South Area Park Athletic F--ield . . _ 1 19 areas along the river), and was judged to be less costly to develop than site #2. Furthermore accessibility at the Riverton . site was determined to be excellent. The Riverton site was also well suited in terms of its relationship to the County Urban Trails system, the County Earlington Park project, and Tukwila's plans to acquire additional streambank property in the vicinity of the Foster Golf Course. Further studies. of the development costs associated with the site were undertaken by the Seattle Department of Engineering.. Their studies indicated that the development costs of the Riverton site would be much greater than originally anticipated (there were extensive peat deposits on the site which would have to be 'removed). The appraisal for the property under consideration also turned out to be considerably higher than anticipated -- considerably beyond available acquisition funds. Due to excessive acquisition and development costs at the Riverton site, attention was directed to a new site about 2 1/2 miles to the southeast of the Riverton site (and slightly south of the primary service area specified in the Jensen Report). This site, the 'Riverview Dairy Farm', is situated within the corporate limits of Tukwila, between Interurban Avenue and the Green River, just upstream of the junction of the Green and Black river courses (see Site Location Map, page 13). The 51 acre site was studied in terms of its suitability for the proposed park and athletic facility complex and found suitable in terms of accessibility, development costs, compatibility with 20 adjacent land uses and applicable development plans and policies. The City and County determined that this site was well suited to their needs and purchased this site at an appraised value of $938,000. Both prior to acquisition and since acquisition, the City of Tukwila has participated in the planning and approval of the project. c. Financing: King County submitted an application for and received matching funds ($429,000) from the Department of Housing & Urban Development for acquisition of the Riverview Dairy Farm site in Tukwila. The construction budget for phase I of the project as previously specified is $2,050,000. d. Citizen participation: Two public meetings have been held regarding the development of South Area Park at the Riverview Farm site. The first was held on August 8, 1973 at the Tukwila City Hall, for the purpose of discussing alternatives for pro- viding public access (vehicular and pedestrian) to the site. A second public meeting was held on October 10, 1973 at the Seattle Park Department offices for the purpose of presenting and dis- cussing the Master Plan and phase I development proposals. Both meetings reflected a consensus of opinion regarding the plans presented. Some concern was expressed as to why Seattle would be scheduling and maintaining a regional facility located in . another city. The response is that approximately 70% of the persons using the formal athletic facilities will be Seattle residents working and /or living in the Duwamish Valley. 21 Scheduling of events will be coordinated with adjacent munici- palities (including Tukwila) and school districts. 5. Relationship with existing laws, policies, plans: . Permits Required: Substantial Development Permit: The project requires . applica- tion for a substantial Development Permit pursuant to the State Shoreline Management Act of 1971. The project site is situated within the Green River floodplain and its associated wetlands, and as such is a part of a 'Shoreline of Statewide Significance' as defined in the Act. This permit will be reviewed and approved By the City of Tukwila. Corps of Engineers Permit: A Corps of Engineers Permit will not be required in connection with the project, as neither the Green or Black rivers are formally designated as navigable waters subject to the jurisdiction of the Corps of Engineers. The navigable portion of .the Duwamish River terminates at the confluence of the Green and Black rivers. Coast Guard Permit: The United States Coast Guard delimits navigable waters as extending up the Green River to the area of the Andover Industrial Park. As such, they require that a Permit for the construction of a bridge over navigable waters be submitted pursuant to the General Bridge Act of 1946. This permit is administered locally by the Commander of the Thir- teenth Coast Guard District. Departments of Game & Fisheries: A Hydraulics Permit is re- • quired as the supports for the vehicular bridge encroach on the water course.; of the Green River. As of yet a final determination of the bridge design has not been specified. The . perimeter diking of the site along the river course will not formally require a Hydraulics permit, but will proceed under consultation with the. State Department of Game. Flood Control Zone Application: The proposed project is located . within the Green River Flood Control Zone District (Flood Control Zone II) established pursuant to the State Flood Control Zone. Act (R.C.W. 86.16). The Act requires that construction projects undertaken within specified flood control districts be issued a Flood Control Zone Permit by the Department of Ecology. The County Division of Hydraulics will review the application sub- mitted for this permit forwarding their recommendations to the Department of Ecology. Parking Facility Permit: A permit for the proposed parking facilities pursuant to the Federal parking management regula -: tion will not be required, as this program has been temporarily Conformance with Applicable Plans and Policy Guides: King County Comprehensive Plan: The South Area Park and Athletic Facility is in full conformance with applicable provisions of the 23 King County Comprehensive Plan. Applicable policies are given below: "Multiple uses of open space land should be encouraged, provided that the uses are compatible and adequate area is provided for each specific function." "Athletic fields should be located functionally conveni- ent to major arterials for ease of access and for handling of the traffic generated by the facility." "Athletic fields should be so distributed that each major section of the metropolitan area is served." developed . athletic fields normally require from 40 to 50 acres of usable space." "Suitable open. space adjacent to streams and waterways should be reserved to partially meet the potential re- creation demand while at the same time safeguarding the natural drainage areas within the County." South Area Park will adjoin and be a part of a proposed river park and trail system planned for the entire Duwamish- Green River upstream possibly as far as the Tacoma City watershed. The Earlington Park project, part of which is already in King County ownership, is planned for early acquisition and will provide an additional two miles (approximate) of riverfront park and trail property downstream from the South. Area Park project. City'.of Tukwila Comprehensive Plan: The South Area Park and Athletic Field is in full conformance with the Tukwila .Compre- hensive Plan. The parcel on which the park will be constructed is currently zoned M -1, light industry. Park and recreational land uses are permitted within this zoning category. The City of Tukwila (Planning Department and City Council) have been involved in the planning of`the park, are familiar with the plan, and have informally endorsed it. Puget Sound Governmental Conference: Interim Regional Develop- ment Plan: The proposed plan is consistent with the plans, policies, and programs adopted by the Governmental Conference for the development of the Central Puget Sound Region. The Govern- mental Conference in reviewing the project plans as a part of the A -95 project review process employed in approving the H.U.D. matching funds, also indicated that the project conforms with the policies established in the Intergovernmental Agreement for the Acquisition and Development of Open Space. Washington State Comprehensive Outdoor Recreation and Open Space Plan: The South Area Pork project, with 4,000 feet or more of riverfront, helps to meet the statewide identified need for more.streambank public access. This site is particularly important in this respect, since it is located within a highly urbanized area. The deficiency in space in King County for special regional type facilities, of which a major athletic field of the type envisioned is one, was judged to be over 2,000 acres in 1970. This was based on the standard in the state plan of 5 acres /1,000 persons for other regional facilities. 'Washington State Shoreline Management Act of 1971 (Guidelines): The location and planning of the South Area Park and Athletic Facility generally complies with the developmental guidelines promulgated by the Department of Ecology under the mandate.of the Shoreline Management Act. Specific instances where the project is eithercentrally'responsive to the guidelines, or in maximum feasible compliance given the nature . of the project and site are pointed out in the portion of this statement dealing with environmental impacts.. Actions /Decisions remaining prior to Implementation (Construction) of Phase I of, the project: 1. Approval of Flood Control. Permit (Department of Ecology) 2. Approval of Coast Guard Bridge Permit (Coast Guard) 3. Approval of Substantial Development Permit (Tukwila) 4. Approval of Hydraulics Permit (Fisheries and Game Departments) 5. Approval of Building Permits 6. Design Review by King County, Design Commission 7. Submittal of Final Environmental Impact Statement 26 EXISTING CONDITIONS 1. Natural Setting: . Physiographic Setting and Features: The project site is situated along the bottomlands formed by the Duwamish, Green and Black Rivers. The site is located just upstream (south) of the confluence of the Green and Black River courses, at a point where the river valley broadens in a southerly direction into the Kent /Auburn Valley. To the north, the valley narrows between two upland areas (.150' to 300' in elevation) and then broadens again into the Duwamish industrial area and waterway. The project site and adjacent floodplain areas are a part of a mature river floodplain, which in the past has been subject to considerable seasonal flooding. More recently, the flooding . problem has been sharply reduced, the Green River Valley having been equipped with a variety of flood control measures. In particular, the Howard Hanson Dam, located approximately 30 miles upstream from Auburn, operates to reduce the seasonal floodwaters to the capacity of the river channel. Also, the East -West Green Deeper soils consist of silts and silty fine sands re- presenting deposits from flooding of the adjacent rivers. 28 Soil investigations made at the site indicate that soil conditions are suitable for construction of light structures, and roads given prescribed site preparations. Drainage on the site is generally good, but subject to a seasonal high water table and ponding at the lower central eastern part of the, site. In general the native valley soils characteristic of the site are highly fertile and well,suited for lawns and general play areas. Athletic fields may require.a coarser sandy soil with less clay or silt than that characteristic of the indigenous soils. d. Habitats: 1. Plant life: Due to the most recent use of the site as pasture, much of the site is covered with a thick growth of grass up to 1 foot in length. The site is completely devoid of trees except for scattered . maples growing along the railroad tracks, and occasional alder, cottonwood, and willow seedlings growing along the river bank, fencing, and river dike along the southern edge of the site. In addition, the edges of the site evidences a considerable variety of ruderal brush and herbaceous weed species. Much of the river bank is grown over with blackberries up to 4 feet in height which generally'extend down the bank to the edge of the water. 29 2. Animal Life: The site provides two general habital types: open ruderal (farmland) and freshwater shoreland. Although the level of industrial development and ambient noise surrounding the site are such that it is unlikely that the site is utilized or inhabited by any rare or endangered species of animal life, a variety of waterfowl and freshwater birds were observed in and adjacent to the pond on the east side of the site (during. July), In this regard it is notable that the pond is definitely a year round phenomena -- as there was a significant volume of water present even during July and August of. 1973, a period of time when western Washington was generally experiencing a drought. Mallard ducks, Sandpipers, and Long - billed Dowitchers were observed feeding along or in the pond. Also observed on the site were Cliff Swallows, Killdeer-and Savannah Sparrows. Presumably this site accommodates-a variety of other birds, both resident and migratory, which are attracted to the freshwater shoreland and open ruderal habitats. While the supply of parallel habital areas in the immediate vicinity of the project has been substantially reduced in recent years due to increasing industrial and commercial development in the valley, the proposed use of the South Area Park and 30 related plans (on the part of King County and local cities) for acquisition of additional open spaces adjacent to the Green and Duwamish rivers, are directed toward assuring a continued supply of similar bank habitats, river No specific survey has been made of other terrestrial mammals found on the site, although the site habitat suggests the possible presence of moles, skunks, . rats, raccoons, mice, shrews, weasels, rabbits, etc., all of which inhabit a variety of similar areas over extensive parts of North America. On-site observations during July revealed the presence of Threespine Sticklebacks in the pond. While these fish provide a potential food to certain species of birdlife, such as Herons, no such birds have been ob- served on the site, nor are they likely to be, given the noise generated by the frequent passage of•trains immediately adjacent to the pond. The Green - Duwamish River supports a wide variety of fish species, a study by Metro indicating the presence of 30 different species of fish. Of particular signifi- cance are the runs of chinook, coho, and chum salmon which migrate upstream past the project site as adults in the fall and downstream as fry and fingerlings in the 31 spring. Although there is some natural spawning in the Green River, the majority of the chinook salmon fry and fingerlings are released from the Washington State Department of Fisheries Hatchery located on Creek, a tributary of the Green River. Other fishes identified in the immediate vicinity of the site include the Threespine stickleback, Mountain whitefish, Stacy flounder, Prickly sculpin, Cutthroat trout, Longnose dace and Speckled dace. The upper Duwamish River, downstream of the site has also been found to have Northern squawfish and Staghorn sculpin. The Green - Duwamish River system has been estimated by the State Departments of Game and Fisheries to yield an annual fish harvest valued at $3,300,000. e. Hydrology /Drainage: As noted previously, the South Area Park site is located on the Green River floodplain, at a point about 12 miles upstream of the mouth of the Duwamish. As such the average and flood condition flow characteristics of the river have a critical bearing on the potential use and development of the site. The average flow of the river over the last ten years has been about 1,500 cubic feet per second. During flood conditions (assuming a 100 year flood) and a release from Howard Hanson Dam of 12,000 cubic feet per second (measured at Auburn), the flow adjacent to the site (in- cluding local inflow from the Green River Valley Drainage 32 System) could reach approximately 15,000 cubic feet per second which would result in the surface of the Green River reaching an elevation of 23.3' at the southern and upstream portion of the site, and 21.8.' the northern extremity of the site. At this elevation the river would flood much_ of the site as it currently exists, depositing silt and probably engaging in some new channel cutting along tha river channel. 2. Human Environment; a. Land Use: 1. General Pattern in Vicinity of Project Site: general the valley floor in the vicinity.of the subject site consists of a developing industrial and commercial area. The area is generally within the corporate limits of the City of Tukwila, but encompasses portions of Renton, and unincorporated King County. Until recently much of the valley floor has been used for agricultural purposes but improved flood . control measures in conjunc- tion with the excellent railroad and highway access . have encouraged increasing industrial and commercial develop- ment. The industrial area is generally an extension of Seattle's major industrial district following along the bottom lands formed by the Duwamish, Green and Black Rivers. North of the project site, industrial development has been somewhat retarded by the narrow character of the valley. The narrowness of the valley in conjunction with the meandering character of the Duwamish has precluded the existence of accessible large land parcels in this area. The presence of Foster Golf Course has also retarded . further southern extension of industrial development in this portion of the valley. To the south a major change in the general land development pattern occurred with the . development of the South Center Shopping Center which was developed shortly after the construction of Interstate 5 and Interstate 405, and the associated Tukwila Interchange. South Center and adjacent industrial parks now dominate developmental pressures to the south of the project site. To the south and east of South Center, industrial activities (including the Boeing Company Space Center) have developed rapidly, extending as far south as South 180th Street. In summary, the area in the general vicinity of the project is a dynamic area of industrial and commercial activities and can be expected to continue to reflect a high rate of growth. Its location at the intersection of Interstate 5 and State Highway 405 gives it a strategic position for vehicular transportation. The availability of major railroad lines through the neighborhood provides easy rail access. Accessibility to waterborne commerce is also 34 comparatively good, with. Seattle's major harbor area a short distance to the northwest. Facilities for airborne commerce are also available nearby, there being easy access to Seattle- Tacoma International Airport. Planning and zoning within Tukwila and Renton suggest that the . bulk of the remaining valley land in the area will be developed for commercial or industrial uses. The higher lands to either side of the valley have been developed with residential and limited commercial uses. Recently there has been an increase in the development of multiple family residential units along the hillsides. 2. Land Uses Immediately Adjacent to site: On the 17.3 acre site immediately south and across, the river from the park site, Don Koll Northwest is planning a. condominium business park. The business park will include 9 office buildings and 17 light industrial buildings, none of which will exceed 10,000 square feet in floor area or 21 feet in height. The site is planned to provide for ve- hiculax ingress and egress from Interurban Avenue, drive- ways to the various buildings and their associated parking areas, parking for over 700 vehicles, truck loading areas, and landscaping. The proposed buildings will be clustered such that office areas will be oriented outward toward the river channel. The bulking of the truck loading areas and light industrial areas \ill be centrally located (oriented inward on the site). Generally the site has been planned FOSTER GOLF BLACK RIVER QUARRY UMPING P RESIDENTIAL•' DEVELOPME ER ERLINGTON GO COURSE MONSTER ROAD RES TRACK DJ .CE ;T..__L SE/ I CT aT ES 36 as a landscaped 'campus -like' environment. The condominium business park and South Area Park will share a joint access road to Interurban Avenue, with a separate access road and bridge providing access to the South Area Park site. The road to the park site will include a separate. landscaped pedestrian and bicycle pathway. To the west of the site across the river on the bank east of Interurban Avenue is an existing apartment complex. On the west side of Interurban Avenue along the base of the hillside there are a tavern, a gas station, and more apart- ment complexes. Above the 150' elevation on the hillside there are a series of apartment complexes, and areas of single family residentail development. Farther north along the western side of the river there are vacant land, some single family residences and several manufacturing plants. Zoning both north and south of the site in the area between Interurban Avenue and the railroad tracks is M - 1, providing for light industrial uses. The strip of land between Inter- urban Avenue and the hillside to the west is zoned C - 2, for local retail uses. To the north and east of the railroad tracks on the hill- side is the Black River Quarry operation. South of the quarry operation in the Black River channel is the main pumping plant of the Green River Valley Drainage System. The area between Monster Road and the railroad tracks is owned by the. Container Corporation of America and zoned for heavy industry. Further south and to the east of Monster Road is the Metro Renton. Sewage Treatment Plant. Between the Metro plant and the railroad tracks there is also a sand and gravel products manufacturing company. Most of the property further to the southeast (bordered by Metro, Interstate 405, and the railroad tracks) is owned by Burlington Northern. BNSF 3. Use of site: The project site is one of the last remaining major undeveloped tracts of its size in the im- mediate area. This is due in part to its physical limita- tions (the site being subject to possible flooding). and the difficulty of providing adequate vehicular access. Previously the site has been used for dairy farming - there being a house, barn, complementary outbuildings and perimeter fencing on the site. These improvements however have not been used in recent years and are obsolete and in a state of substantial disrepair. In the appraisal made of the site, the highest and best use of the site (defined as that use which at the time of ap- praisal is most likely to produce the greatest net return to the land and /or buildings over a given period of time) was specified as industrial. 38 b. Activity nodes of significance in the area: The two major activity nodes in the immediate vicinity of the project site are the South Center Shopping Mall and the Longacres Race Track, both of which are to the south of Interstate 405. Both of these facilities generate a significant amount of vehicular traffic. Other facilities related to recreation in the vicinity of the project site include the Earlington Golf Course (a private course) situated northeast of the Renton Treatment Plant, Foster Golf Course (a private course) located north of the park site along the Duwamish River, and Tukwila Park, a small park with tennis courts and picnic facilities, situated on the hillside above the intersection of Inter- urban Avenue and Three Tree Point Road. c. Transportation Systems: 1.. Highways and Roads: South Area.Park is easily reached by vehicle, either by way of Interstate 5 and Interstate 405, or along. Interurban Avenue (assuming the presence of a bridge across the Green River). There is also limited vehicular access from the east side of the site by way of Monster Road. In particular there is a railroad crossing at the extreme southeast corner of the site. A second existing means of vehicular access is by way of a railroad track undercrossing and roadway at the extreme northeast corner of the site connecting with Monster Road (South 143rd Street). Monster Road is a narrow 2 -lane winding road which is not slated for any significant improvements . in the foreseeable future. The Black River Bridge, crossing the water channel connecting the Pumping Station with the Green River, is a narrow 2 -lane bridge, also in need of repair. During the Longacre racing season, Monster Road is heavily traveled. After races Monster Road is temporarily restricted to one- way northbound. traffic. The Black River Quarry operation also generates considerable heavy truck traffic along Monster Road during their operating . hours from 8:00 a.m. to 5:00 p.m. on weekdays. Interurban Avenue on the west side of the Green River, is a recently improved arterial facility with a five lane crossection - -the fifth lane serving as a two way left turn lane. Interurban Avenue intersects with and passes under Interstate 405 about a half mile south of the site. Access to and from Interstate 405 (a limited access freeway) is provided from Interurban by a . "parclo" interchange, with both ramps to Interurban being signalized. 2. Railroads:, Along the eastern side of the site there are two mainline railroad tracks, the Burlington Northern tract and the Milwaukee track. Train traffic is generally confined to runs between 8:00 a.m. and 9:00 p.m. daily. The bulk of the traffic is slower moving freight. Milwaukee has about 25 trains per day on its track, and Burlington runs from 30 - 40 trains per day. Frequent on -grade road crossings present an on -going hazard to both motorists and the railroads, and the railroads are adamantly opposed to additional at- grade crossings in the area. Currently the tracks run along the top of a filled embank- ment approximately 20 feet higher in elevation than the South Area Park site. 3. Pedestrian /Bicycle Pathways: South Area Park is situated at a major junction in King County's proposed Urban Trail System. Specifically, the park site is situated at .a point where the Duwamish River Trail (extending from East Marginal Way to the Black /Green River junction) ties into the Duwamish- Green -Cedar River Loop trail.. When com- pleted this trail will extend from the south -end of Seattle to the Green River Gorge, then north to the Cedar River and back to the Seattle- Renton area, running along the Cedar and Black River Channels. The intent of this portion of the trail system is to connect Seattle, Renton, Tukwila, Kent, Auburn, and eventually Tacoma. The intent is also to utilize existing levees and riverside roadways to connect recreation areas, parks and river access points. 41 According to the King County Urban Trails Plan, South Area Park is to function as a major rest point along the trail system. The park site is designated as an appropriate point for the provision of restroom facilities, parking facilities (such that cyclists could initiate day trips from South Area Park), trail mileage markers, and a Black River Channel Point -of- Interest marker. From a point somewhere in the vicinity of the confluence of the Black and Green River courses one trail segment will head east toward Renton in'the vicinity of the old Black River chan- nel and another will head southward toward Tukwila, adjacent to the riverbank in the park site, across the proposed new bridge, and returning to the Interurban right -of -way. Planning is currently underway in both Renton and Tukwila to evaluate alternative trail corridors in conformance with the general routing specified by the County Trail Plan and the proposed plans for South Area Park. d. Utilities: Water, sewer and electrical utilities are all available in the vicinity of the site. Sewage from the site will be pumped directly into the Metro Renton Treat- ment Plant. Potable and irrigation water will be supplied from Tukwila's 8" water main along Interurban Avenue. Electrical power [for heating and lighting] will be sup- plied by Puget Sound Power and Light's transmission line running along Interurban Avenue. Storm water will be routed directly into the Green River. 42 Pollutants 1. Air Quality: According to the Puget. Sound Air Pollution Control Agency, the only air pollutant of signi- ficance with respect to the proposed site and its intended use is the concentration of carbon monoxide generated by vehicular traffic. The only current indication of carbon monoxide levels in the general vicinity of the project are those readingssrecorded by the Department of Ecology at a monitoring station on East Marginal Way. One -hour concen- trations of carbon monoxide, as recorded at this station, have not exceeded the national 1 -hour standard since the station began monitoring air quality in 1972. The 8 -hour national standard was exceeded 17 times in 1972, but only . once in the first 10 months of 1973. Air pollutants are not easily dispersed within the lower Green- Duwamish River Valley, given that air circulation within the valley is constricted by surrounding higher land plateaus. 2. Water Quality: According to the RIBCO Water Quality Management Study Interim Report, the Green River currently evidences the following water quality problems. 1.) High water temperatures during the summer attributable to low river flow and inadequate shading along the watercourse;. 2.) Low concentrations of dissolved oxygen due to aerobic degradation of organic wastes - a process which is accelerate( by higher water temperature; 3.) High coliform counts; and 4.)_. High nutrient inflows to the Duwamish River and estuary. 43 None of these conditions in their current state have been documented to have adversely affected the fish life of commercial or recreational significance. The State of Washington has classified surface water bodies into several quality classes relating to their suitability for a large•number of potential uses. The lower segment of • the Green River is classified A (Excellent). According t a use classification suggested by. the Environmental Pro - tection Agency, such a water body would be suitable for "human contact recreation." However, the Green River is generally not suited to swimming activities because of its appearance and general environmental context. The river is both well suited to and utilized for boating. activities (involving cartop rowboats, canoes, rubber rafts, kayaks, etc.) both for recreational.boating and fishing activities. 3. Noise Levels: The South Area Park site is subject to considerable noise from adjacent activities. Traffic moving along Interurban Avenue contributes to an ambient noise level which, measured from the center of the site, is about 44 - 50 decibels. Intermittent train traffic generates short term noise from 55 - 65 decibels. Another frequent source of intermittent noise is generated by overhead air traffic. Prop and jet aircraft; approaching_ and taking off from Boeing Field 4nd to a lesser degree Sea -Tac Airport)_generate 65 - 70 decibels on the site. 44 Noise from the Black River Quarry operation. (jackhammer) is frequently heard during week days generating a noise level of about 55 decibels. f. Human Values: As noted previously, the appraisal study made of the South Area Park site indicates that its highest and best use in terms of the real estate market is industrial activities. However, the private market is not responsive to public open space and recreational needs. State, Regional, and County planning studies have all pointed to an urgent public need for more water related recreational and open space areas. The need is particularly great along the Duwamish -Green River waterway as it is the only significant river within the more urbanized portions of King County. Increased open space is also needed along • the waterway to preserve and enhance its natural drainage and wildlife habitat functions. ENVIRONMENTAL IMPACT 1. Natural Environment a. Site Geology, Topography, Soils: The superficial topography of the site will be substantially rearranged. • Approximately 50,000 yards of supplementary materials will be brought onto the site in connection with creation of the new earth berms and playing fields. Principal grading will involve leveling of athletic field areas and forming of a perimeter earth berm and earth berms associated with the stadium seating areas. The top of the berm, which will be about 14' wide will vary from 23.3' at the southeastern corner of the site to 21.8' near the northern tip of the site. As such, the top of the perimeter berm will be equal to the elevation of the Green River during 100 year flood conditioning. The top of the berm will also function as a flood control easement for flood control equipment. The berm will be set back about 5 feet from the river bank. b. Natural Habitats: Construction of the proposed athletic fields and recreational areas will totally alter the . vege- tative character of the site with the exception of the brush habitats along the slope of the river bank and railroad embankment and the low -lying vegetative mantle in the im- mediate vicinity of the pond on the eastern side of the site. The existing mantle of grass and herbaceous weeds covering the central portions of the site will be destroyed during 46 the regrading and contouring of the athletic fields,, building up of the earth mounds used for stadium seating and defining various playing areas on the site, and the construction of vehicular roadways and parking areas, pedestrian pathways, and the perimeter earth berm. The new vegetative cover will consist of expansive lawn areas, grass playing fields, and a variety of buffer strips and groups of assorted planted trees. The net effect of the proposed site alterations in con- junction with retention of the pond area and indigenous vegetative habitats in the vicinity of the river bank, will be to increase the limited variety of wildlife in- habiting the site. In particular, currently present bird species and land mammals, all of which either thrive in or at least tolerate a high level of urban activities, may be expected to continue to inhabit peripheral areas of the site and pond. The large number of new trees proposed as a part of the proposed site landscaping may be expected to encourage additional bird species and varieties of land mammals (squirrels, etc.) which characteristically inhabit wooded urban parklands, to inhabit the site. c. Hydrology: Construction of the park as proposed will have a limited but significant impact on the operation of the Green River floodplain. The perimeter berm being con- structed on the site will generally confine floodwaters 47 within the primary river channel area but allow for some broadening,of the flow between the edge of the primary channel and the berm during high flooding conditions. The effective floodplain for floods of a lesser magnitude than a 100 year flood, but exceeding the primary river channel carrying capacity, will be reduced by approximately 20. - 30. .acres (a portion of the site which would normally flood under such conditions). A flood exceeding, 100 year flood conditions would inundate the site. Under such circumstances the site would function as a reservoir, gradually releasing the water by way of the on-site pumping system utilized to control the level of the retention pond. The vehicular bridge being constructed over the Green River will be constructed so as not to reduce or obstruct the channel capacity of the river. The underside of the bridge span will be at or higher than 27.3-feet elevation (an elevation .3 feet higher than the river flowing at 14,000 cfs -- under 100 year flood conditions). On site surface drainage will be considerably altered, in part due to the construction of on site parking areas, and in larger measure due to the construction of an extensive. drainage and irrigation system on the site. Surface run- off from the athletic fields, parking areas, and roadways will be channeled by culvert to the retention pond on the east side of the site. The water level of the retention Fit MI IUUHIRIIII rArKi`r'E E► V OF= Gr`TY ]- TU KW I -A l�'� I L ►rY\ 6 OUNDIt 'a AIDE N.EAN 1.0W WATcK = tx.111 M kN F+( &H WAT" 42A.,31 N '1;2? `19? -4- N,V,1• -Z -4 rwrof4D • waJ+.: r . & $ rj \eK AT TUKWIL c WASH. �JKI�l� CCUHTY PrLIc4TIot !Y: ,rte K11J6 C oisr( PNKCNrr zT'ulze Ptvisi c ,1 fir, or 1/. t WMMUNU N D�/wM N ,DfT 4 ANta -1 1/74 I�ET' 1 OF 2. PL-A14 22,4-iA -.4 • • -- -o" t1-1164H NM< RV, K.C.A h• • P4\/ATiot4 AT TU0/11.Pc WA40I-t. IN r'EM' KIN& CaNTY -0A-rutiv, MM-1 Le:vr.t. AM- 6AT I ON KING CCUI•111 D1vr.-.1aN coMMUN.ITY re-\/1.1)PAAr,t4i 4 1100-1 1,74 ':-flr" ton 50 pond will be controlled byy way of a pump, which will divert excess water to a culvert which will carry it to the Green River. It is expected that excess runoff water will be pumped from the retention pond intermittently between the months of November and March. The altered character of the surface and vegetative . cover of the site may reduce the amount of water normally absorbed and held by the site during periods of high precipitation and released during drier periods. The surface runoff of the site diverted to the retention pond and in turn to the Green River, will be accelerated during periods of high precipitation. 2. Human Environment /Values: a. Traffic: Based on estimates prepared by the Seattle Parks. Department much of the vehicular traffic generated by the proposed athletic facilities. will occur during week- day evenings, after 7:00 p.m. and on weekends. Morning use of the facility will generally occur after 9:00 a.m. Afternoon•use on week days is expected to be light, the maximum expected week day afternoon parking requirement being 40 cars. For the most part, traffic generated by non- tournament and practice games will be highly dispersed over time. 51 Traffic peaks will be associated with major games staged in the stadium facilities. Such games will . generally be scheduled on week days after 7:00 p.m. or on weekends. As such, the periods of park usage which will generate the greatest volumes of traffic will not occur during peak traffic hours normally encountered along the adjacent freeway and arterial facilities. Accordingly, . traffic operations involving intersections . with such facilities are not expected to be adverse. Peak traffic conditions generated by the park generally will represent less than 10% of the carrying capacity of adjacent arterials. The following three figures illustrate the location of the adjacent freeway and arterial facilities that will be utilized for vehicular access to the site, their respective current average daily traffic volumes, and the estimated peak hour traffic which will be generated by the proposed park. facility. Traffic conflicts arising out of the joint access road (meeting Interurban Avenue at the existing Three Tree Point intersection) serving both the park and the proposed condominium business park immediately south of the site, are expected to be minimal. The Three Tree Point inter- section is currently signalized and has ample room to provide for stacking and left turn lanes. The peak hours • 55 of traffic generation by the park and condominium complex are not expected to coincide either in terms of the time of day or the predominant directions of vehicular approach. During the racing season, Longacres attracts about 1,000 cars on weekdays and 1,500 cars on weekends. The majority of this traffic is carried on Monster Road, east of the park site and railroad track alignment. Incoming traffic to Longacres occurs around 4:30 p.m. on weekdays and 1:30 p.m. on weekends. Traffic leaving Longacres generally peaks at about 9:30 p.m. on weekdays and 6 :30 p.m. on weekends. Due to the fact that very little park - generated traffic is expected to use Monster Road, and Monster Road serves as a primary northerly vehicular ingress and . egress route for Longacres, little traffic conflict is expected between park related traffic and Longacres traffic. b. Land Use: 1. Adjacent Land Uses: The industrial activities situated to the east of the site, east of the railroad track alignment, are not expected to experience any signi- ficant impacts as a result of the proposed park project. As noted earlier, park related traffic along Monster Road is expected to be negligible, and as such should not in- terfere with trucking activities associated with the industrial activities east of the site. Fencing will be placed along the east site, to both reduce the hazard of persons being on or adjacent to the railroad tracks and define the edge of the park site. The fence will also . reduce the potential for trespass onto adjacent industrial properties east of the site or the railroad alignment. There will be a passage provided through the fence at the northern end of the site, where there will be pedestrian access to the site by way of the existing underpass. The condominium business park to the south of the park, as previously noted will be sharing an access road off of Interurban Avenue with the park. While vehicular traffic is not expected to generate any significant ingress or egress conflicts there may be occasional vehicles, pedes- trians or bicyclists who, in the process of gaining access to the park may inadvertently enter into the business park. area. Noise generated by park facility users should be minimal and generally not audible from across the Green River, especially given the relatively high levels of ambient noise typical of this portion of the Green River Valley. The greater levels of noise which may be anticipated in association with athletic events staged at the soccer and baseball stadiums (scheduled for future construction at the southeast corner of the site) will occur outside of normal working hours. 57 One impact on adjacent land uses which may be of signi- ficance will be the effect of the night time athletic field lights associated with the proposed stadiums. These lights, at least some of which will be oriented in a gen- erally westernly direction (two softball fields and the track & field event stadium are oriented toward the west) will frequently be on as late as 11 p.m. during the spring, summer and early fall months. These lights may annoy residents in •apartments situated to the west of the. Green River. Any problems of this type which arise will be proportionally less for apartments or homes situated higher up on the hillside, as the field lights will be directed downward on the playing fields. The light that will be seen from across the river will be peripheral to the primary orientation of the field lights, . and as such, of a much lower intensity than that focused on areas receiving primary illumination. Certain roadside businesses, such as gasoline stations, restaurants, and taverns may experience some increases in business stemming from the number of people who will be drawn to the area in pursuit of recreational activities. While picnic facilities will be provided on site, some individuals may opt to patronize local eating or drinking establishments, and /or purchase needed supplies (gasoline, 58 supplementary groceries, etc.) in association with their use of the park facilities. In relation to this probability, facilities such as the proposed park and athletic field complex may potentially generate a litter problem both on- site and along adjoining pathways and roadways. On the other hand, the proposed facility will provide a major visual amenity both for persons driving along Inter- urban Avenue, and for the residents living on adjacent hillsides. The site plan has been developed to maximize the natural aesthetic potential of the river as viewed from west of the river. While the landscape character of the site will be dramatically different than the site's current state, the new landscaping, consisting of grass turf,athletic fields, pedestrian pathways, and sizable areas of trees (both around and within the central parking areas as well as at points along the perimeter pathway and in the vicinity of the retention pond) will provide a siz- able year -round green space adjacent to the Green River. The park and athletic facilities will also provide recrea- tional opportunities for residents living in the immediate vicinity of the park site. c. Resultant Pollutants: 1. Water: Water pollutants, deriving from indirect sources, entering the surface run -off water of the site, will be one of the most significant adverse environ- mental impacts associated with the project. Both during the initial preparation of the athletic field surfaces and as a part of the ongoing maintenance of the park and athletic facilities, there will be substantial amounts of fertilizer applied to the playing fields. Initial applica- tions are expected to consist of 10- 2a -20. (a potash, phosphate, nitrogen mixture) which is a moderate nitrogen level fertilizer typically used for park lawn areas and athletic fields. The potential problem posed is that of . nitrogen and other nutrients leeching out of or otherwise draining from the site into the Green River. To the extent that this occurs it will contribute to an increased potential for algae blooms and increased levels of bio- chemical oxygen demand both in the on -site retention pond and in the Green River. The indication is that an even lower level.nitrogen fertilizer will be used in connection with the ongoing maintenance of the park. This will further reduce but not eliminate the park site's contribution to nutrient levels and biochemical - oxygen- demand in the Green River. No regular program of insecticide, herbicide or fungicide use will be included in the park maintenance program. However, ;herbicidesmay ,,be used on an. occasional., basis. 60 As such, the intended use and operation of the park should not generate significant quantities of the "persistent" or "exotic" pollutants associated with the synthetic organic chemicals included in such products. Other water pollutants generated on site will include increased water temperatures, deriving from the increased heat absorption associated with surface run -off and retention pond water which will be pumped into the Green River; and the hydrocarbons, lead salts, and other pet- roleum product related pollutants which are likely to enter the surface run -off from the proposed parking areas and vehicular roadways. d. Resource Commitments: 1. Land: South Area Park will utilize. approximately 51 acres of land which would otherwise be utilized for industrial development or agricultural activities. The . parcels potential for productive agricultural exploitation is diminished by its size and the fact that it is not directly contiguous to other agricultural lands. 2. Water: The project will not divert any water from the Green River. Water for irrigation and on -site plumbing facilities will be tapped from the Tukwila water system, bL which in turn is supplied from the Seattle water supply. Water draw is estimated at 200 -'450 gallons /minute during peak irrigation months. Maximum draw would occur no earlier than 10:00 p.m. and no later than 6:30 a.m. on a daily basis during peak irrigation months. 2. Air: The increased vehicular traffic which the proposed peak will generate in the area will contribute to the levels of various air pollutants associated with the com- bustion of carbonaceous fuels. According to the Puget Sound Air Pollution Control Agency, the air pollutant of primary concern in the vicinity of the project is carbon monoxide. National ambient air quality standards have been specified for carbon monoxide as follows: 8- hour average- 9 parts per million or 10 milligrams per cubic meter; 1 -hour average -'35 parts per million or 40 milli- grams per cubic meter. Information regarding current. carbon monoxide levels at the site has not been available or acquired. However monitoring of carbon monoxide levels has occurred from a monitoring station near the Duwamish River (located at 6770 East Marginal Way) about 6.5 miles northwest of the project site in the heart of Seattle's major industrial district. The 8 -hour standard was ex- ceeded 17 times in 1973 and only once during 1973 at the Duwamish monitoring site. The 1 -hour standard has not been exceeded at this site since monitoring was initiated in 1972. 62 Vehicular traffic generated in association with the proposed park and recreational facility uses may con- tribute to maximum 8 -hour average concentrations of carbon monoxide, but is not expected to contribute to maximum 1 -hour concentrations by virtue of the fact that the peak traffic associated with the park will generally not coincide with peak rush hour traffic. Peak 1 -hour concentrations of carbon monoxide and related exhaust pollutants are generally associated with peak traffic conditions. 3. Energy: Energy consumption associated with the project will stem principally from field lights, roadway and parking area lighting (including night time security lighting) and the consumption of fossil fuels by motor vehicles utilized by persons in getting to and from the site. Approximate hourly Kilowatt consumption rates have been estimated as follows: softball field lighting - 55 kw each; football /soccer field lighting - 100 kw; baseball field lighting - 150 kw; parking, roadway, and general nighttime security lighting - about 30 kw total. The net impact on consumption of electrical energy is difficult to estimate in that an undetermined percentage of the individuals attending such night games would in- dividually or by group represent entire households 63 (families,or single individuals) who in attending such , events are at the same time substantially reducing their consumption of electricity at home. Other individuals attending such events presumably represent only portions of entire households in which case their attendance at evening games would not tend to result in a significant reduction of household electrical energy consumption. Generally speaking net per capita electrical consumption for those individuals attending near - capacity games, will be about the same as if the individuals stayed home. An additional resource commitment will stem from the gasoline consumption which will occur as a result of most park users arriving at the park by way of private auto- mobile. No attempt has been made to quantify the vehicular miles -of- travel or gasoline consumption associated with people gaining access to the park - -in part because a sig- nificant but undetermined amount of the travel associated with the park will represent alternative- opportunity- travel rather than travel which would not otherwise be occuring. Increased travel to and from the athletic field will in many cases be replacing other forms of recreation requiring vehicular travel. UNAVOIDABLE ADVERSE IMPACTS /MITIGATING MEASURES: 1. Natural Environment: Construction of the proposed park and athletic facilities will unavoidably entail re- structuring the majority of the site topography and /or replacement of the majority of the existing vegetative mantle. Many of the components of the original vegetative cover, in - areas other than the portions of the site which have been designated for athletic fields and supportive facilities, will . be retained in their current state. The pond will be deepened but will be retained as a visual and wildlife habitat amenity. Alterations of the pond will tem- porarily disrupt and permanently alter the pond habitat. It is unlikely that the completed retention pond will attract the variety of birdlife that currently feed at it. However, the pond is being retained in part as an area attractive for ducks and birds attracted to freshwater shorelines. The . river bank will be undisturbed except for temporary and limited excavations during the construction of the drainage culvert from the retention pond to the Green River, and construction of the bridge supports. Development of the site to accommodate the proposed _. athletic fields and associated facilities necessitates taking reasonable . precautions against flood damage (which would consist principally of silt deposits on the fields). The perimeter berm will protect the site from flooding, but have the effect of reducing the effective Green River floodplain for floods of less severity than that of a 100 year flood. The effective floodplain for extraordinary floods will not be affected. 2. Human Environment/Values: The proposed park and athletic facility will unavoidably result in some increases in vehicular traffic in the area. The amount of vehicular traffic generated will be minimally reduced upon completion of adjacent segments of the King County Urban Trail. To the extent that individuals can be pursuaded to form car pools or use buses (public or private), vehicular traffic and its associated contribution to air pollution problems will be reduced. Reductions in the air pollution problem can also be expected as further steps are taken to realize the Federal ambient air quality standards by way of controlling air pollution sources (automobile exhaust emissions, etc.). Operation of the park and athletic facilities at the South Area Park will also unavoidably result in some additional water pollutants reaching the on -site pond and Green River. The quantities of nitrogen and other plant nutrients reaching the pond and Green River will be minimized both by using low level nitrogen fertilizers and by way of judicious application techniques. Generally, surface run -off and drainage water. from the site will be pumped into the Green River only during periods of higher precipitation and river flow. The remainder of the year such water will collect in the retention pond. The potential increases in water temperature deriving from surface run -off water will be partially mitigated as a result of the shade provided by new trees ,. scheduled for planting in the vicinity of the retention pond, adjacent to the river -bank, and adjacent to the roadway and parking areas. Hydrocarbons and lead salts from roadway and parking area run -off will be captured in part by the catch basins to be provided. No significant adverse impacts are anticipated with respect to existing and probable future adjacent land uses, with the exception of spill -light from the athletic field lights. The project will reduce the effective property tax base of Tukwila. ALTERNATIVES TO THE PROPOSED ACTION: 1. Delete Project: Deletion of the park and athletic facilities program proposed for south Seattle and southern King County, would have several significant impacts. The 50 - 70 acres needed for such a facility, would be available for alternative land uses - -most likely. either agricultural uses or industrial uses--similar to the uses which currently occupy some of the sites which were considered for the proposed park and athletic facilities. Agricultural uses, if situated adjacent to the river channel would tend to contribute to water quality problems, as a reeult of the run -off of excess plant nutrients (fertilizers). Industrial uses would tend to generate increased peak hour traffic along . arterials which in many cases are running near or at their capacity during rush hour traffic. With industrial uses there . would also be the potential for water pollutants entering the river from parking area surface runoff. Either industrial or agricultural uses would continue to restrict public access to the Duwamish /Green River, although river -side trails could conceivably be accomodated in conjunction with either of these uses. Industrial or agricultural uses would contribute to the tax base of whatever jurisdictions they are located within. On the other hand, deletion of the proposed park and athletic facilities would seriously jeopardize the recreational op- portunities of many Seattle and King County residents. Both the potential users of the proposed facility and current users of many existing athletic facilities in south Seattle and southern King County would be without access to suitable athletic fields. Existing local community and neighborhood facilities are either completely inadequate or overused. Other facilities are not only distant, but generally scheduled to capacity. The nearest water oriented passive recreational facilities are Seward Park Qn Lake Washington, Lakewood Park, and Lincoln and Seahurst Park on Puget Sound. While local communities anticipate acquiring open space along the Green. River, local funding capabilities have severely constrained the realization of this intent. . Accomodation of park and athletic fields at alternative sites: As noted in the initial description of the proposed action (page 16) a series of sites (all located several miles or more to the north of the site which was acquired) were considered for the development of the proposed project. The original analysis of alternative sites was a part of the study,.. A Study of South Area Park and Athletic Field prepared by David Jensen Associates in 1968. The Jensen study compared the alternative sites in terms of their suitability for the proposed program and the compati- bility (probable impact) of the intended land use with adjacent activities. With the exception of the South Park site* ( #6 located adjacent to West Marginal Way and South Roxbury) and the Riverton site *The actual site which was acquired in Tukwila (adjacent to the Green River and Interurban Avenue) and site #6 of the original range of alternative sites considered in the Jensen report are referred to respectively as the South Area Park site and the South Park site. 69 (See page 17) all of the alternative sites considered were contiguous to. the Duwamish Waterway. All of the alternative sites considered are adjacent to major traffic arterials and generally situated amidst industrial and /or general commercial uses. As such all of the environmental impacts already discussed in conjunction with the project at the South Area Park site (acquired in Tukwila) could also be expected if the project were developed at sites 1, 2, 3, 4, or 4a. In addition to these shared impacts, development of the project at alternative sites 1 or 2 would have entailed preemption of prime industrial parcels fronting on navigable portions of the Duwamish waterway. Sites 5 and 6 both have problems with drainage which would be costly to resolve, and were not well suited for passive recreational uses. Furthermore they would not have contributed to the objective of providing more open space along the Duwamish /Green River. The Tukwila site proposed for development of the project is south of the primary.service area defined by a survey of potential users. However, Interstate 5, Interstate 405, and Interurban Avenue function to make the acquired site generally convenient both with respect to the originally identified primary service area and an area of growing need further to the south. 3. Alternative Site Programs (South Area Park site): Con- sideration has been directed toward defining an appropriate use- emphasis (athletic fields and facilities versus passive recreational areas and opportunities) for the project. Existing policy assigns high priority to both types of recreational activity. While the South Area Park site has a range of attributes, which suggest its suitability for passive recreational uses (its location along 4,000 feet of the Green River at the confluence of the Green and Black River channels, its location with respect to the King County Urban Trail system; the need for more water oriented passive recreational opportunities in'the area), other locational . attributes detract from its passive recreational potential (ambient noise levels and moderate levels of visual amenity outside of river course). As designed at least some of the passive recreational opportunities are envisioned as supportive with respect to the more formal athletic. facilities. It is anticipated that the children's play area and picnic facilities will be used to a substantial degree by families, -- members of which will also be utilizing the athletic fields. Another major user group which will be using picnic, bench, and rest - room facilities will be bicyclists or others using the urban trail system which will eventually interconnect with the park. Beyond these uses the park will also afford opportunities for fishing, passive strolling; sitting, jogging, bird watching, etc. Overall however, its primary use is programed for and will consist of more structured athletic activities. The practice athletic fields will also provide excellent areas for kite flying and flying of model airplanes. 4. Vehicular Access and Parking: a. Off -site parking: Several off -site parking possibi- lities have been considered. One alternative would entail acquisition of land in the vicinity of the Village Green apartments on the west bank of the Green River. Another possibility would entail a joint parking lot venture with the developer of the condominium business park proposed for the parcel of land to the south across the Green River from the park site. Either one or a com- bination of these alternative parking area arrangements would require the construction of a pedestrian bridge to the site from the parking areas. Emergency vehicle access (fire trucks, medical vehicles, and police) would have to_be provided access to the site either by constructing a pedestrian bridge so that it can also function as an emergency vehicle bridge, or by providing for emergency vehicle access from the east side of the site. Emergency vehicle access from Monster Road has been determined to be inadequate at best. Plans for realignment 72 of portions of Monster Road would require that emer- gency vehicles pass under a railroad trestle near Longacres (the clearance of which is inadequate for fire trucks) and then approach the site either by way of the existing at -grade railroad track crossing at the south end of the site where the fencing and gate used to keep people off the tracks would hinder emergency vehicular access, or by way of the railroad track undercrossing at the northeastern corner of the site. The northern access point would present problems both from the standpoint of vertical clearance and the possibility of flood water on the lane. The major beneficial impact of providing off -site parking and restricting on -site vehicular access solely to-emergency vehicles, would be a gain of approximately 4 acres of cm- site area could be used for additional athletic fields and/ or passive recreation areas. Additionally, on -site pedestrian vehicular conflicts would be eliminated. However there are also disadvantages of off -site parking. In many instances, people using the athletic facilities (including event participants bringing considerable athletic gear) would have to walk as far as 2,000 feet. This problem could be reduced by splitting up the off- site parking into several lots with separate pedestrian bridges to different sections of the site. This 73 alternative would be costly and would have only a limited effect in terms of reducing distance between parking areas and athletic fields. All of the off -site parking arrangements would entail costly land and right- of-way acquisitions. Each of the off -site parking area locations would also have tended to create parking and access conflicts with adjacent property uses. In general, significant environmental impacts associated with on or off -site parking are about comparable. The major trade off between on and off -site parking revolves around user convenience and construction costs. Gains in on -site usable space deriving from off -site parking are counterbalanced by loses in user. convenience (great distances between parking areas and athletic facilities). Costs associated with constructing bridges suitable for use by emergency vehicles are high relative to the amount of vehicular use which would occur. As such it is pro- posed that full vehicular access (regular and emergency vehicles) be provided to the site with on -site parking areas provided. On site parking will be dispersed to provide parking areas convenient to the various athletic facilities and recreational areas. b. On -site Vehicular Access & Parking: Seven principal . points of vehicular access to the site were considered. 74 The two eastern approaches (the southern at -grade railroad track crossing and the northern railroad trestle undercrossing) were rejected because of the circuitous travel routes they would entail for most park users, conflict with existing traffic patterns and capa- city along Monster Road, high cost of necessary improve- ments to Monster Road, and the high potential for accidents- -both on Monster Road itself and at the railroad crossing.. The railroad track underpass at the north end of the site is additionally unsuitable because of its 15' elevation, which makes it subject to occasional flooding. Four principal vehicular access approaches were considered along the west and south sides of the park property- - all of which would entail bridging the Green River and interconnecting with Interurban Avenue. From the stand- point of the convenience of park users, any of the approaches from Interurban Avenue would be much more direct than the east side approaches considered. All of the approaches from Interurban Avenue share the potential for limited traffic conflicts on Interurban Avenue during periods of heavy traffic associated with Longacres. On the other hand, conflicts with Longacres traffic would be . even greater if park access was provided from Monster Road. 75 The environmental impact differentials associated with the various approaches from Interurban Avenue principally . entail traffic hazards, possible traffic conflicts with adjacent activities, and encroachment of right -of -way expansions onto abutting. properties. The preferred access point provides access to the site from the south across the proposed site of the condominium business park, meeting Interurban Avenue at the existing Three Tree Point Road Intersection by way of a shared roadway. This access scheme is being proposed because it provides access at an existing signalized intersection, is closest to Interstate 405 for convenient regional access, and because there is adequate space at the intersection for stacking and left turn lanes. While the Three Tree Point inter- section has a record of many accidents, new intersections created elsewhere along Interurban would also increase the potential for accidents along Interurban, possibly more so than converting the Three Tree Point intersection into a four way signalized intersection. The Three Tree Point intersection is especially well suited for vehicular access to the condominium business park proposed for the trail south of the park site. Its joint use by the park and the condominium development, for access to Interurban. Avenue, will tend to generate fewer traffic hazards than would occur if separate access points are provided for the two developments. As noted earlier, while there is a 76 possibility for some traffic conflict between park users and vehicles coming and going from the condominium busi- ness park, the different peak use times of the two facilities, is expected to minimize this conflict. Other alternative access routes, from Interurban to the park site, were considered at 144th - Street, 147th Street, and at a point between 144th and 147th Street. Possible access (and bridging of the river) in the vicinity of the Village Green apartments would be both hazardous and technically difficult to achieve given the flood clearance requirements for bridges and safety requirements pertaining . to roadway vertical curves. Providing access by way of the 144th Street right -of -way, would require additional right -of -way acquisition and generate possible conflicts with industrial traffic which would share access on 144th. Access by way of the 147th Street alignment would also require additional right -of -way acquisition and would restrict access flexibility at the Village Green apart- ments on the west bank of the river. Both of these al- ternatives however would utilize existing intersections, creating minimal additional traffic hazards along Inter- urban Avenue. One other access route would have been by way of a new right -of -way and bridge alignment midway be- tween 144th and 147th Streets. This route would require purchase of a new right -of -way and creation of a new 77 intersection along Interurban Avenue. It would not, how- ever, interfere or conflict with adjacent land uses. All of the access routes from Interurban Avenue would satisfy the needs of emergency vehicle access.. RELATIONSHIP BETWEEN LOCAL SHORT -TERM ENVIRONMENTAL USES AND THE MAINTENANCE AND ENHANCEMENT OF ENVIRONMENTAL PRODUCTIVITY: The primary immediate and long term effect of the South Area Park and Athletic Facility complex will be the retention of water oriented open space for purposes of public recreation, relaxation, and enjoyment of outdoor environmental amenities and recreational opportunities. Beyond this, the park site will provide an on -going visual amenity for passers -by (vehicu- lar traffic, train traffic, pedestrians and cyclists). In terms of natural environmental systems the proposed park will continue to .function as a habitat for a variety of species of birds and terrestrial mammals. However some of the species of birds and mammals which currently use the site for feeding or seasonal habitation will be displaced as a result of the more intensive human presence and landscape treatment of the site. As contemplated, the proposed park will also have a negligible but cumulative effect (in the sense of its being one of many 78 contributing sources of water pollutants) on the quality of water and fish resources within the Duwamish /Green River watershed. Operation and maintenance of the park will un- avoidably entail minute quantities of fertilizers and petro- leum related pollutants entering the Green River. Over time, it can be expected that technical and operational refinements will enable further reductions of these effects. Insofar as park users depend on vehicular access to the site, the park's presence will also potentially contribute to air pollution problems. The nature of the air pollution problem requires that it be addressed at a broader scale and in terms of source emissions. The National Environmental Protection Agency is promulgating regulations to reduce air pollution at its various sources. In summary, the South Area Park project is proposed to enhance . both the immediate and long term environmental productivity (in terms of the potential stream of public benefits) of a portion of the Green River channel and its associated flood plain area. IRREVERSIBLE OR IRRETRIEVABLE RESOURCE COMMITMENTS: The primary resource commitment associated with the construc- tion of the South Area Park and Recreational Facility complex, 79 is the commitment of 51 acres of land to recreational and open space uses. The commitment is of the nature of a flow commitment in the sense that the aesthetic and recreational . attributes of the site are being committed to the on -going use and enjoyment by the public. The commitment made is neither irreversible or irretrievable in the sense that current, previous, or alternative site uses could be reinstated at the site without unreasonable costs or delay.