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HomeMy WebLinkAboutOrd 1755 - Storm and Surface Water Management (Repealed by Ord 2064) .��ILA,. w _s 0 r ¢I r 1908, f T ukwfia C ity o Washington Ordinance No. 7 Sie AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF TUKWILA, WASHINGTON, RELATING TO SURFACE AND STORM WATER MANAGEMENT; AMENDING ORDINANCE 1523 AND CREATING TMC SECTION 14.28.080 TO ESTABLISH PENALTIES AND PROCEDURES FOR CHAPTER VIOLATIONS; PROVIDING FOR SEVERABILITY; AND ESTABLISHING AN EFFECTIVE DATE. WHEREAS, Ordinance Nos. 1523 and 1549 and Resolution No. 1672 of the City Council established a surface water utility, adopted a comprehensive surface water plan and established surface water charges; and WHEREAS, King County has updated its Surface Water Runoff Policy and has implemented a Surface Water Design Manual; and WHEREAS, the City Council finds that the public health, safety and welfare would be promoted by establishing similar comprehensive and technical requirements for management of surface and storm waters and to include a Surface Water Drainage Design Manual; WHEREAS, implementation of surface water management requirements on future development needs to include these objectives: Encourage single family residential housing revitalization, maximum use of large lots and infill of the city's residential neighborhoods. Encourage small neighborhood commercial businesses by allowing affordable places to start these businesses. NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUKWILA DO ORDAIN AS FOLLOWS; Section 1. Title, Purpose, Scope and Definitions. 1.0 Title This Ordinance shall be known as the City of Tukwila "Storm Water Management Ordinance" and may be so cited. 1.1 Purpose The purpose of this Ordinance is to: A. Control and /or prevent adverse impacts to private and public property and threats to public safety associated with surface water runoff. B. Establish minimum requirements and procedures to prevent damages to watercourses, wetlands, and surface water conveyance systems. C. Establish and enforce storm drainage standards for development activities in the City of Tukwila. D. Formally adopt the City of Tukwila Storm Water Management Plan. E. Implement application of surface water requirements in such a manner to encourage single family residential housing revitalization by 1) maximum use of large lots and 2) infill of the city's residential neighborhoods. Also, encourage small neighborhood businesses by allowing affordable places to start these businesses. 1.2 Scope This Ordinance sets forth rules, regulations, and processes to control storm drainage activities within the City of Tukwila. 1.3 Definitions STORMWT9.DOC 11121195 1 Adverse Impact Any deleterious effect on waters or wetlands, to include but not limited to, effects involving: quality, quantity, surface area, species composition, aesthetics, usefulness for human or natural uses, biological productivity, diversity, and /or stability. Agricultural Land Management Practices Those practices employed commercially and /or by residential households to cultivate land for crop production which ensure conservation of related soil and water resources. Applicant Any person, firm, or governmental agency proposing to carry out storm drainage activities in connection with development of a project subject to review under the Storm Water Management Ordinance. Best Management Practice, or "BMP" means physical, structural and /or managerial practices that, when used singly or in combination, prevent or reduce pollution of water. Biofiltration The simultaneous processes of filtration, infiltration, absorption, and biological uptake of pollutants in stormwater that take place when runoff flows over and through vegetated treatment facilities. Biofiltration (Water Quality) Swale An open vegetated drainage channel providing water quality treatment of surface and storm water runoff through biofiltration as specified in the King County Surface Water Design Manual. Buffer (Also known as "Sensitive Area Buffer) The area contiguous to a sensitive area that is required for the continued maintenance, function, and structural stability of the sensitive area. (Refer to Sensitive Areas Ordinance No.1599.) Clearing Any removal of trees, brush, grass, ground cover or other vegetative matter from a site which exposes the earth' s surface at the site. Design Storm A rainfall event which is selected by the Engineer for purposes of design, specifying both the return period in years and the duration in hours (e.g., 25 yr. /24 hrs). Detention The release of stormwater runoff from the site at a slower rate than is collected by the stormwater facility system, the difference being held in temporary storage. Detention Facilities Facilities designed to hold runoff while gradually releasing it at a predetermined maximum rate. Development For the purposes of this Ordinance any activity that requires a permit or approval, including but not limited to a building permit, land altering permit, flood control zone permit, shoreline substantial development permit, conditional use permit, unclassified use permit, zoning variance or reclassification, planned residential development, subdivision, short subdivision, master plan development, building site plan, or right -of -way. Development Standards The formally adopted standards prescribing the specific manner in which development is to take place in the City of Tukwila. Director of Public Works the Director of the Department of Public Works for the City of Tukwila, or Public Works Department Staff designated by the Director to discharge the requirements of this Ordinance. Drainage Activity See "Storm Drainage Activity Drainage Facility Structures or features, natural or artificial, that convey, treat, and /or abate surface water runoff, including but not limited to detention facilities, retention facilities, and drainage retention /abatement facilities. Drainage Review An evaluation by the City staff of a proposed development's compliance with the drainage requirements in this ordinance and the Surface Water Design Manual. Drainage System The drainage system comprised of natural and artificial structures that convey surface water within the City of Tukwila. This system includes pipes, culverts, ditches, water courses, lakes, rivers, ponds, and detention and retention ponds, as well as other types of conveyance facilities. Drainage Treatment /Abatement Facilities Any facilities installed or constructed in conjunction with a drainage plan for the purpose of treating storm and surface water runoff to improve water quality, excluding retention or detention facilities. Engineer A professional engineer licensed by the State of Washington. Engineering Plans The drawings, plans, specifications, contracts and permits which depict how construction is to occur. Erosion /sedimentation Control Any temporary or permanent measure taken to reduce erosion, control siltation and sedimentation, and ensure that sediment laden water does not leave the site. Ground Water Water in a saturated zone or stratum beneath the surface or land or a surface water body. STORMWT9.DOC 11/21/95 2 Illicit Discharge All non -storm water discharges to stormwater drainage systems that cause or contribute to a violation of state water quality, sediment quality, or groundwater quality standards, including but not limited to sanitary sewer connections, industrial process water, interior floor drains, car washing, and gray water systems. Impervious Surface Those hard surfaces which prevent or retard the entry of water into the soil in a manner that such water entered the soils under natural conditions prior to development; or a hard surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Such surfaces include, but are not limited to, rooftops, asphalt or concrete paving, compacted surfaces, or other surfaces which similarly affect the natural infiltration or runoff patterns existing prior to development. Interflow That portion of rainfall or other natural source of water that infiltrates into the soil and moves laterally through the upper soil horizons until intercepted by a stream channel or unit that returns to the surface (e.g., wetland, spring or seep). King County Surface Water Design Manual (as defined in this ordinance) The manual (and supporting documents as appropriate) describing surface and storm water design and analysis requirements, procedures and guidance which is hereby adopted by reference. A copy of the Manual is on file in the office of the City Clerk for use and examination by the public. In application of the King County Surface Water Design Manual, the minimum design standards of the Washington State Department of Ecology' s Technical Manual shall also be met. Master Drainage Plan The adopted City of Tukwila Surface Water Comprehensive Plan, April 1993 or update. Natural Location The existing location of those channels, swales, and other natural conveyance systems as currently defined for the subject property, either from maps or photographs, or such other means as appropriate. Permittee Any person obtaining a Storm Drainage Permit in accordance with this Ordinance. Pervious Surface Any surface that significantly reduces surface runoff by rapid infiltration into permeable soils or by retention /absorption/ transpoevaporation by plant cover. Plan See Engineering Plans. Pollutant Any substance which, when added to water, would contaminate or alter the chemical, physical, or biological properties of any waters of the City' s drainage system or of the State. This includes a change in temperature, taste, color, turbidity, or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive, or other substance into any waters of the City's drainage system or of the State as will or is likely to create a nuisance. It also includes any substance which renders such waters harmful, detrimental, or injurious to the public health, safety, or welfare, or to domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses, or to livestock, wild animals, birds, fish, or other aquatic life. Private Drainage System Drainage systems located on private property and designed to discharge directly as through pipes, channels, etc., or indirectly as sheet flow, subsurface flow, etc. into the City' drainage system. Public Drainage System That portion of the drainage system of the City located on public right -of -way or other property owned by the City, and those portions of drainage systems maintained in a public easement by the City. Public Works Director see Director of Public Works. Receiving Bodies of Water Creeks, water courses, lakes, and other bodies of water into which drainage systems are directed, either naturally, in ditches, or in closed conduit systems. Redevelopment means on an already developed site, the creation or addition of expansion impervious surfaces, structural development including construction, installation or expansion of a building or other structure, and /or replacement of impervious surface that is not part of a routine maintenance activity; and land disturbing activities associated with structural or impervious redevelopment. Retention Facilities Facilities designed to hold water for a considerable length of time and then release it by evaporation, plant transpiration and /or infiltration into the ground. Runoff Water traveling across the ground surface as a result of precipitation or other natural source. Sediment Solid particulate matter, both mineral and organic, that has been or is being transported from its original site by water, air, gravity, or ice. Sensitive Area Wetlands, watercourses, landslide hazard areas and abandoned coal mines as designated or defined by the City of Tukwila Sensitive Area Ordinance Number 1599. Sensitive Area Buffer See "Buffer STORMWT9.DOC 11/21/95 3 Site A legally defined section of real property, whose boundaries are recorded for purposes of assessing taxes with the County Assessor's Office, where storm drainage activities are proposed; which may include all contiguous land and /or water in one ownership, or being developed as a unit, although not necessarily at one time. Small Parcels Parcels which do not meet the threshold requirements for formal drainage review as outlined in Sections 1.4,1.5 or 1.7 of this Ordinance. Stabilization The prevention of soil movement by any various vegetative and /or structural means. Storm Drainage Activity Any activity involving design /construction of surface water facilities that control or affect surface and storm water, including new facilities, modifying or abandoning existing facilities. Storm drainage activity is recognized if the threshold criteria of this Ordinance is met or exceeded as defined in Section 1.5 of this Ordinance. Storm Drainage Plan See Engineering Plans Storm Water Water originating from rainfall and other precipitation that is found in drainage facilities, rivers, water courses, springs, seeps, ponds, lakes and wetlands as well as shallow ground water. The term "runoff" is synonymous. Storm Water Control Measures: Quality Control Measures Qualitative control of storm water runoff through a system of vegetative, structural, and other measures designed to reduce or eliminate pollutants that might otherwise be carried by storm water runoff. Quantitative Control Measures Quantitative control of storm water runoff through a system of vegetative, structural, and other measures designed to mitigate increased volumes and rates of flow brought about by man -made changes to the land. Storm Water Standards Those drawings, details, and requirements adopted by the City of Tukwila, which depict the manner in which storm water control measures and associated facilities must be constructed and maintained. Surface Water The naturally occurring water that flows over or is stored upon the earth' s surface (a.k.a. storm water). Temporary Control Measures Quantitative or qualitative drainage controls for construction or emergency activities. Temporary Drainage Facility Temporary structures or features, natural or artificial, that convey, treat, and /or abate surface water runoff. Water Course Any course or route formed by nature or modified by man, generally consisting of a channel with a bed and banks or sides substantially throughout its length along which surface water flows naturally (other than the Green /Duwamish River). The channel or bed need not contain water year- round. Water courses do not include irrigation ditches, the storm water system or other entirely artificial water courses unless they are used by salmonids or to convey sections of streams. Watershed The total drainage area, separated by a ridge line or other `highest point' topographic feature which contributes runoff to a single point. Wetland An area that is inundated or saturated by ground or surface water at a frequency and duration sufficient to support and, that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, bogs, and similar areas (Army Corps of Engineers Regulation 33 CFR 323.2(c)). Constructed wetlands are not considered wetlands for the purpose of this Ordinance, however, those artificial wetlands intentionally created from non wetland areas to mitigate conversion of wetlands as permitted by the City shall be considered wetlands. Wetponds Drainage facilities for water quality treatment that contain a permanent pool of water, usually four feet in depth, that are filled during the initial runoff from a storm event. They are designed to optimize water quality by providing retention time (on the order of a week or more) in order to settle out particles of fine sediment to which pollutants such as heavy metals absorb, and to allow biologic activity to occur that metabolizes nutrients and organic pollutants. Wetvaults the same as wetponds except that permanent pool of water is covered by a lid which blocks sunlight from entering the facility, limiting the photodependent biologic activity. 1.4 The Drainage Review and Drainage Permit Process Developments in the City of Tukwila that propose storm drainage activities or trigger any of the land use /development activities listed below in Section 1.5 of this ordinance, require a DRAINAGE REVIEW (See Sections 1.7 through 1.9 for requirements). STORMWT9.DOC 11/21/95 4 If CONSTRUCTION of drainage facilities will result from the land use /development activity or drainage activity, then a DRAINAGE PERMIT will be applied for (See Section 2 for requirements). The DRAINAGE REVIEW and DRAINAGE PERMIT may be applied for as one application. EXEMPTIONS and THRESHOLDS for applying for the DRAINAGE REVIEW and DRAINAGE PERMIT are listed in Sections 1.5 and 1.6 of this ordinance. SMALL PARCELS. For development that includes drainage features and facilities, but is exempt from the criteria listed above and is not adjacent to a flood plain or sensitive area, a plan showing connections (if connecting) to the public drain system will be submitted as part of the building permit. This drain plan does not have to be done by an engineer. Additional temporary erosion controls will be in accordance with the City's Land Altering Ordinance and erosion control methods will be in compliance with Tukwila' s Erosion Control Standards (available at the permit counter). 1.5 Drainage Review When Required A. A drainage review is required for any proposed development activities listed in Subsection B of this Section which would: 1. Add more than five thousand (5,000) square feet of new impervious surface; or 2. Collect and concentrate surface and storm water runoff from a drainage area of more than five thousand (5,000) square feet; or 3. Contain or abut a floodplain, stream, lake, wetland or closed depression, or a sensitive area as defined by ordinance or as determined by the Public Works Director. B. The following land use /development activities will be required to have a drainage review if the project involves any of the planned actions listed in Subsection A of this Section: 1. Commercial building; 2. Conditional use; 3. Formal subdivision (plat); 4. Land altering /sensitive area and /or Flood Zone Control permit; 5. Master plan development; 6. Planned residential development; 7. Residential development (up to 4 single family lot developments), each lot will be considered a separate land use /development activity for purposes of drainage review and application of threshold design requirements of this Ordinance. 8. Right -of -way use; 9. Shoreline substantial development; 10. Administrative subdivision (short plat); 11. Special use; 12. Unclassified use; 13. Zoning reclassification. 1.6 Illicit Discharges Illicit discharges to stormwater drainage systems are prohibited. 1.7 Drainage Review Requirements A. Storm Water Design Standards All storm drainage activities shall be undertaken in accordance with the following criteria and standards: 1. Design Criteria.. Storm water management measures shall be designed and constructed in accordance with the standards and specifications as set forth in the Surface Water Design Manual, January 1992, or as amended hereafter, published by King County Public Works Department Surface Water Division, and shall further meet the requirements of the Department of Ecology, if such Department of Ecology standards are more restrictive. 2. Additional Criteria in Basin Plans. Where the City of Tukwila Comprehensive Storm Water Management Plan or City drainage basin plans prescribe specific design criteria, this criteria will supplement the Manual requirements. STORMWT9.DOC 11/21/95 5 3. City Development Standards. Specific detail drawings and design criteria for storm drainage facilities and storm drainage activities shall also be constructed or undertaken in accordance with applicable City of Tukwila Development Standards. 4. Storm water detention and /or water quality treatment will be required on -site unless a variance is granted or an existing regional facility is utilized or new one constructed. 5. A regional facility, if approved by the Council, will be constructed as part of the development, with latecomer's fees attached to other future developments. Also, at the Council's discretion, the regional facility may be constructed through the formation of a ULID. Finally, the City may elect to build the facility, and assess a latecomer' s fee. B. Core Requirements. Every permit or approval application with drainage review required by Section 3 of this Ordinance must meet each of the following core requirements which are described in detail in the Surface Water Design Manual; 1. Core Requirement #1. Discharge at the natural location. The discharge from a project site must occur at the existing location and /or produce no significant adverse impact, as described in the Surface Water Design Manual. 2. Core Requirement #2. Off -site analysis. All projects must identify the upstream tributary drainage area and perform a downstream analysis. Levels of analysis required depend on the problems identified or predicted. At a minimum, a Level One analysis as described in the Surface Water Design Manual must be submitted with the initial permit application. 3. Core Requirement #3. Runoff control. All projects shall provide runoff controls to control the quantity and quality of runoff from the project by limiting the peak rates of runoff from design storm events to the predeveloped peak rates based on the project site' s existing runoff conditions. The design volume, when detention facilities are required by the Surface Water Design Manual to meet the standard runoff control performance curve for the two- and ten -year, twenty -four hour duration design storm events, shall be increased by a thirty percent factor for safety. This factor of safety shall be reviewed as new research is completed to evaluate its effectiveness. 4. Core Requirement #4. Conveyance system. All conveyance systems for projects must be analyzed, designed and constructed for existing tributary off -site flows and developed on -site flows from the project. 5. Core Requirement #5. Erosion /sedimentation control plan. All engineering plans for projects that involve modification or significant impact to existing drainage facilities and /or construction of new drainage facilities must include a plan to control erosion and sedimentation during construction and to permanently stabilize soils at the site. 6. Core Requirement #6. Maintenance and operation. Maintenance of all drainage facilities constructed or modified by a project is the responsibility of the property owner as described in the Surface Water Design Manual, except the City may perform maintenance of drainage facilities constructed for formal plat subdivisions, and some short plat subdivisions, two years after final plat recording following an inspection by the City. Special Drainage Fee: When the City accepts drainage infrastructure that requires upkeep in excess of normal maintenance, the City has the right to charge the benefiting parties a special drainage fee to cover costs for this maintenance in addition to the City' s normal surface water charge, as a condition of turnover. 7. Core Requirement #7. Bonds and liability. All drainage facilities for projects (except downspout roof drain infiltration systems) must comply with the bond and liability requirements of Sections 2.61 and 4 of this Ordinance. 8. Core Requirement #8. Water Quality Control. Proposed projects shall provide water quality treatment facilities to mitigate polluted storm and surface water runoff generated by the addition and /or replacement of five thousand square feet or more of impervious surface whose usage or existence causes pollutants to enter the surface water drainage system. These facilities shall meet the applicable design and performance criteria of the City of Tukwila Comprehensive Storm Water Management Plan or City drainage basin plans prescribing specific design criteria which differ from those stated in the Surface Water Design Manual. C. Special Requirements. In addition to the core requirements, engineering plans must also meet any of the following special requirements which apply to the project and which are described in detail in the Surface Water Design Manual: 1. Special Requirement #1. Critical drainage area. If a project lies within an area designated by Ordinance or by the Public Works Director (Refer to Section 1.8 of this Ordinance) as a "critical drainage area then the project drainage review and engineering plans shall be prepared in accordance with special critical drainage area requirements adopted by the Public Works Director. STORMWT9.DOC 11/21/95 6 2. Special Requirement #2. Compliance with an existing master drainage plan. If a project lies within an area covered by an approved master drainage plan, then the project drainage review and engineering plans shall be prepared bin accordance with any special requirements of the master drainage plan. 3. Special Requirement #3. Conditions requiring a master drainage plan. If a project: a) Is a master planned development as described in an adopted comprehensive plan or other ordinance; or b) Is a subdivision that will eventually have more than one hundred single family lots and encompass a contiguous drainage sub -basin of more than two hundred (200) acres; or c) Is a commercial building permit or planned residential development that will eventually construct more than fifty (50) acres of impervious surface; or d) Will clear an area of more than five hundred (500) acres; then a master drainage plan shall be prepared as specified in the Surface Water Design Manual and submitted with the State Environmental Policy Act (SEPA) checklist. Approval of the master drainage plan is required before permit approval. 4. Special Requirement #4. Adopted basin or community plans. If a project lies within an area included in an adopted basin or community plan, then the project drainage review and engineering plans shall be prepared in conformance with the special requirements of the adopted basin or community plan. 5. Special Requirement #5. Special water quality controls. If a project will construct more than one acre of impervious surface that will be subject to vehicular use or storage of chemicals and a) Proposes to discharge runoff directly to a regional facility, receiving water body, lake, wetland, or closed depression to provide the runoff control consistent with Core Requirement #3; or b) The runoff from the project will discharge into a Type 1 or 2 stream, or Type 1 wetland within one mile from the project site; then a wetpond meeting the standards as specified in the Surface Water Design Manual shall be employed to treat a project' s runoff prior to discharge from the project site. A wetvault or water quality swale may be used when a wetpond is technicallynot feasible. 6. Special Requirement #6: Coalescing plate oil /water separators. If a project will construct more than five acres of impervious surface that will be subject to petroleum storage or transfer, or high vehicular (more than twenty -five hundred vehicle trips per day) or heavy equipment use, storage or maintenance, then a coalescing plate or equivalent oil /water separator shall be employed to treat a project's runoff prior to treatment by a wetpond, wetvault, or water quality swale, and /or discharge from the project site. 7. Special Requirement #7: Closed depressions. If a project will discharge to an existing closed depression either on or off the site that has greater than five thousand (5,000) square feet of surface area at potential overflow, then the project' s drainage review and engineering plans must meet the requirements for closed depressions as specified in the Surface Water Design Manual; 8. Special Requirement #8: Use of lakes, wetlands or closed depressions for runoff control. If a project proposes to use a lake, wetland, or closed depression for runoff controls required by Core Requirement #3, then the project must meet the requirements of the City's Sensitive Areas Ordinance 1599 and Special Requirement #5 for such use, and must observe the limits of any increases to the floodplain as specified in the Surface Water Design Manual; 9. Special Requirement #9: Delineation of one hundred year floodplain. If a project contains or abuts a stream, lake, wetland or closed depression, then the one hundred year floodplain boundaries and floodway, if available, based on an approved floodplain study as specified in the Surface Water Design Manual shall be delineated on the site improvement plans and profiles and on any final plat maps prepared for the project; 10. Special Requirement #10: Flood protection for the Green River /Duwamish waterway. If a project contains or abuts any portion of the Green River /Duwamish waterway that has an existing flood protection facility or involves construction of a new, or modification of existing flood protection facility, then the flood protection facility shall be analyzed and /or designed as specified in accordance with the City' s Flood Ordinance (Ordinance Nos.1462 1499) and in the Federal Emergency Management (FEMA) regulations (Title 44 CFR). 11. Special Requirement #11: Geotechnical analysis and report. If a project includes construction of a pond for drainage control or an infiltration system (excluding a roof downspout system) above a steep slope (as defined in the Surface Water design Manual) within two hundred (200) feet STORMWT9.DOC 11/21/95 7 from the top of the steep slope or on a slope with a gradient steeper than fifteen percent (15 or construction of earth fill /bank armor for flood protection facilities, then a geotechnical analysis and report shall be prepared and stamped by a geotechnical professional civil engineer which shall address, at a minimum, the analysis described in the Surface Water Design Manual; 12. Special Requirement #12: Soil analysis and report. If the soils underlying a project have not been mapped, or if the existing soils maps are in error or not of sufficient resolution to allow the proper engineering analysis for the proposed site to be performed, then a soils analysis and report shall be prepared and stamped by a professional civil engineer with expertise in soils to verify and /or map the underlying soils by addressing at a minimum the analysis described in the Surface Water Design Manual. 13. Special Requirement #13: Source Control. If a proposed project requires a commercial building permit, then water quality source controls shall be applied to prevent rainfall and runoff from coming into contact with pollutants to the maximum extent possible. Water quality source controls shall be applied in accordance with the Surface Water Design Manual. 1.8 Critical Drainage Areas Development in areas where the Public Works Director has determined that the existing flooding, drainage, and /or erosion conditions present an imminent likelihood of harm to the welfare and safety of the surrounding community, shall meet special drainage requirements set by the Public Works Director until such time as the community hazard is alleviated. Such conditions may include the limitation of the volume of discharge from the subject property to predevelopment levels, preservation of wetlands or other natural drainage features, or other controls necessary to protect against community hazard. Application of the provisions of this subsection may be proposed for a variance, provided that the resulting development shall be subject to all of the remaining terms and conditions of this Ordinance. 1.9 Other Laws and Regulations A. State Water Pollution Control Act (RCW 90.48.080), and any other applicable law or regulation will be adhered to in the administration of this Ordinance. B. Whenever conflicts exist between federal, state, or local laws, ordinances or regulations, the more restrictive provisions shall apply, except as prescribed in Section 1.7.A.2 of this Ordinance. C. Neither this Ordinance nor any administrative provisions made pursuant to it: 1. Exempts the Permittee from procuring other required permits or complying with the requirements and conditions of such a permit; or, 2. Limits the right of any person to maintain, at any time, any appropriate action, at law or in equity, for relief or damages against the permittee arising from the permitted activity. Section 2. General Storm Drainage Permit Provisions. 2.1 Permit Requirements The following provisions shall apply to all storm drainage activities permitted within the City of Tukwila, unless specifically exempted by this Ordinance: A. Permit Required A Storm Drainage Permit is required for all proposed storm drainage activities in the City of Tukwila. This permit shall not be issued without first obtaining a Land Altering Permit if required; provided however, that any substantially similar elements as determined by the Public Works Director, required for application to obtain a Land Altering Permit may also be utilized for application to obtain a Storm Drainage Permit. B. Plan Required All work shall be performed in accordance with a sequence shown on an approved Storm drainage Plan. Engineering Plans Contents All submittal procedures, definitions, and specifications for the required contents of engineering plans are presented in the plan review process section of the Surface Water Design Manual. C. Storm Water Control Measures All storm drainage activities shall include storm water control measures designed to maintain post development peak discharges (for the specified design storm event) at levels equal to or less than the pre- development peak discharges -for the same design storm event through control of volume, timing, and rates of flow unless direct discharge into the Green /Duwamish River can be permitted without loosing the function of the downstream conveyance systems under full build conditions for the Duwamish basin. D. Storm Water Quality Control Measures All storm drainage activities shall include storm water control measures designed to maintain or enhance water quality to the standards in effect at the time a Storm Drainage Permit is issued. STORMWT9.DOC 11/21/95 8 E. Additional Requirements for Sensitive Areas In addition to any requirements, standards, and criteria contained in this Ordinance, all storm drainage activities occurring in a Sensitive Area or its Buffer must comply with the constraints and conditions imposed by the Tukwila's Sensitive Areas Ordinance as implemented by the City of Tukwila Department of Community Development. F. Clarification of Requirements The Public Works Director may provide technical updates to the King County Surface Water Design Manual as new technical methods and means become available. 2.2 Permit Authority The Director of the Public Works Department for the City of Tukwila is the responsible administrative officer of this Ordinance and his /her authority includes the establishment of regulations and procedures to carry out the intent of this Ordinance. 2.3 Application for Storm Drainage Permit The application for a Storm Drainage Permit shall be submitted on the standard Utility Permit Application Form provided by the Public Works Department. The Application may also require the following: A. Vicinity Map. B. Site Plan. C. Storm drainage Plan. D. Maintenance Schedules and Agreements. E. Work Schedule and Construction Cost Estimates for each element in the required plans. F. Hydrological Engineering Report. G. H. I. Performance Bond or other Security. Supplemental Requirements /Conditions by the Public Works Director or the Department of Community Development. 2.4 Description of Application Elements /Requirements A. Vicinity Map The vicinity map shall include the following information: 1. Location of proposed storm drainage activities in relation to the local drainage basins as identified by the City of Tukwila Comprehensive Storm drainage Plan on file in the Department of Public Works. 2. Location of all water courses and other natural surface water system elements downstream from the proposed storm drainage activities. 3. Identification of upstream and downstream drainage areas, including watershed boundaries and predominant intra -basin flow paths. B. Site Plan The following information shall be included on the Site Plan for proposed storm drainage activities: J. Water Quality Analysis. SEPA State Environmental Policy Act. Location and description of all watercourses, impoundments, wetlands, and other surface water features on or adjacent to the site. 2. Topography of the site for existing and proposed contours, in two -foot intervals and delineation of slopes. 3. Delineation of the 100 year floodplain, floodway, wetlands, streams and associated buffers. 4. Proposed improvements including location and description of all existing and proposed buildings or other structures, impervious surfaces, and storm drainage facilities, if applicable. 5. Location and identification of all property lines, existing and proposed easements for the storm water management facilities, and easements to provide adequate access for inspection and maintenance from a public right -of -way. 6. Location and identification of all existing and proposed utilities. C. Storm Drainage Plan The applicant is responsible for submitting a Storm Drainage Plan which meets the design requirements, including the requirements of the current King County Surface Water Design Manual, of this Ordinance. The applicant shall specify on the drawings submitted with such Plan that all clearing, grading, drainage, construction and development shall be conducted in strict accordance with the Plan. In addition, any or all of the following information may be required for inclusion in the Storm Drainage Plan: 1. STORMWT9.DOC 11/21/95 9 1. Structural details for and graphic representation of all proposed drainage system components and storm water management facilities, including hydraulic calculations for all system components and notes on drawings specifying materials to be used. 2. Soils analysis, including test borings, which are necessary for construction of small ponds and /or infiltration facilities. 3. Construction specifications for all proposed storm water management facilities. 4. Delineation and description of all temporary drainage facilities, including erosion control, to be employed during construction of the permanent storm drainage system together with a schedule for the maintenance of such interim measures. S. Integration, where applicable, of all storm drainage facilities with the permanent erosion control facilities required by the Land Altering Ordinance and any amendments thereto; provided that such integration shall in no way compromise the effectiveness of such facilities. D. Maintenance Schedules and Agreements for New Drainage Facilities and City Wide Maintenance and Monitoring Program for Existing Private Drainage 1. Minimum Standards The following are minimum standards for the maintenance of storm water facilities by private property owners. a) Facilities shall be inspected annually and cleared of debris, sediment and vegetation when they affect the functioning and /or design capacity of the facility. b) Grassy swales and other biofilters shall be inspected monthly and mowed or replanted as necessary. Clippings are to be removed and properly disposed of. c) Where lack of maintenance is causing or contributing to a water quality or a hazard problem, immediate action shall be taken to correct the problem. If, after notification by the City, the property owner fails to take immediate action to correct the problem, the City may take immediate action to correct the problem, at the property owner's expense. Furthermore, the costs of such work undertaken by the City may be assessed as a lien against the property on which such facilities are located. 2. Maintenance Schedule for New Private Drainage Facilities Prior to receiving a Storm Drainage Permit, the applicant shall provide a monitoring and maintenance schedule for all permanent storm drainage facilities that is binding on all subsequent owners of the land directly served by such facilities and conforms to the following criteria: a) The monitoring and maintenance schedules required herein shall be developed for the life of each storm drainage facility and shall state the maintenance to be completed, the time period for completion, and who shall perform the maintenance. The schedule shall also be printed on the Storm Drainage Plan. b) The monitoring and maintenance schedule shall provide for access to the storm drainage facilities by the Public Works Department and shall be formalized as an agreement between the property owner and the City. Such agreement shall be affixed to the titles of affected properties and recorded with the King County Auditor' s Office. c) The owner of the property on which storm water facilities are constructed pursuant to this Ordinance shall be responsible for maintaining such facilities. Failure of the owner to maintain such facilities as prescribed in the approved maintenance schedule may result in the work being performed at the direction of the Public Works Director. When the property owner has been given prior notification by the City and has not maintained such facilities as prescribed in the approved maintenance schedule, the costs of such work performed by the City may be assessed as a lien against the property on which such facilities are located. This action shall be in addition to any other enforcement provisions provided in this Ordinance. 3. Establishment of City -Wide Maintenance and Monitoring Program for Existing Private Drainage Facilities: By this Ordinance, the City establishes a maintenance and monitoring program for private drainage facilities within the City. All private property owners will maintain their facilities in accord with Section 2.4, D, 1. Also, all private property owners will comply with the following: a) Ownerships will develop a monitoring and maintenance schedule for the life of each existing storm drainage facility that states the maintenance to be completed, the time period for completion, and who shall perform the maintenance. STORMWT9.DOC 11/21/95 10 b) The monitoring and maintenance schedule will provide for the access to the storm drainage facilities by the Public Works Department. c) The owner of the property on which storm water facilities exist will be responsible for maintaining such facilities in accordance with the maintenance standards set forth in the King County Surface Water Design Manual. Failure of the owner to maintain such facilities as prescribed in the approved maintenance schedule may result in the work being performed at the direction of the Public Works Director. When the property owner has been given prior notification by the City and has failed to maintain such facilities in the manner prescribed in the approved maintenance schedule, the costs of such work by the City may be assessed as a lien against the property on which such facilities are located. This action shall be in addition to any other enforcement provisions provided in this Ordinance. E. Work Schedule and Construction Cost Estimates (for each element in the required plans) When required, the applicant shall submit for approval a work schedule and construction cost estimates containing the following: 1. The work schedule shall identify the proposed date(s) when storm drainage facilities will be constructed and when they will be completed. A schedule of proposed date(s) for construction and completion of any interim storm drainage facilities shall also be provided. 2. Construction cost estimates for any required storm water facilities indicted on the Storm Drainage Plan shall be provided in sufficient detail to allow the Public Works Director to determine the appropriate dollar amounts for required securities and /or insurance. F. Hydrological Engineering Report A hydrological engineering report, when required, shall contain all calculations required to determine the suitability of the site for the proposed development as well as the adequacy of all storm water facilities to be constructed, to include: 1. Hydrology of the site including contributions from upstream area as well as subsurface flow patterns and volumes. 2. Hydraulic capacities and design dynamics for all storm water facilities and maximum runoff per design standards. 3. Capacities of the public systems downstream from the proposed development following construction. 4. Maximum water course velocities that can be maintained without significant detriment to the natural channels (e.g., scouring, sedimentation, erosion, etc.). 5. The predicted path that storm water runoff will take during storm events which exceed system design capacities. G. Water Quality Analysis When required, the applicant shall provide baseline data for storm and surface water quality entering the site per the parameters indicated in the current storm water standards. Such data shall be accompanied with conclusions regarding the positive and negative effects of the development on the water quality downstream from the site as well as the predicted effects of on -site water quality mitigation improvements, to include biofiltration systems as required per King County Surface water Design Manual. Documentation and test data supporting all conclusions and recommendations as well as notes delineating any hazardous substance storage areas and proposed plans to protect water courses from potential adverse impacts associated with such storage shall also be provided. H. SEPA (State Environmental Policy Act) A Storm Drainage Permit will not be issued prior to the completion of the SEPA environmental review, when required by the Department of Community Development. I. Performance Bond or Other Security The Public Works Director may require from the applicant a surety, cash bond, irrevocable letter or credit, or other means of security acceptable to the City, prior to the issuance of a Storm Drainage Permit. Such securities shall be administered in accordance with Section 4. The amount of the security shall not be less than the total estimated construction cost of all interim and permanent storm water control facilities and shall not be fully released without final inspection and approval of completed work by the City and the provision of "as- built" plans. Supplemental Requirements /Conditions 1. General. The Public Works Director may require supplemental studies, inspections, and /or testing by an approved testing agency at any stage of the application or project. In addition, he /she may require other conditions deemed necessary to prevent the storm drainage activities from being conducted in a manner hazardous to life or property, or in a manner likely to create a nuisance. All conditions must be identified on the Storm Drainage Plan submitted for approval. J. STORMWT9.DOC 11/21/95 11 2. Insurance. If, in the opinion of the Public Works Director, the nature of the work is such that it may create a hazard to human life or endanger adjoining property, property at a higher elevation, property at a lower elevation, any street improvements, or any other public property, the Public Works Director shall require the applicant to file a certificate of insurance in a timely fashion. Certificates of insurance shall be administered as prescribed in Section 4.3. 3. Special Conditions by the Department of Community Development In cases where the proposed storm drainage activities discharges to or alters a sensitive area, as defined in the Sensitive Areas Ordinance, or any amendments thereto, the City of Tukwila Department of Community Development may require additional conditions or requirements on the storm drainage plan prior to issuance of the storm drainage permit. 2.5 Issuance of Storm Drainage Permits A. Permits are not transferable without the approval of the Public Works Director. B. In issuing a Storm Drainage Permit, the Public Works Director may waive the requirement for any or all plans or specifications upon finding that the information on the application is sufficient to demonstrate that the proposed work will conform to the requirements of this Ordinance, other laws and ordinances, and the Comprehensive Storm Water Management Plan provided, however, that a waiver of any section of this Ordinance shall not be construed as a waiver of any other requirements of this or related regulations and the applicant shall remain bound by all conditions of the application. C. Permit Processing /Timing 1. Within 60 days of receipt of an completed application for a Storm Drainage Permit (including all required accompanying information), the Public Works Director will review the application to determine if the requirements of this Ordinance are met. The Public Works Director may request comments from other departments or agencies. 2. If the requirements of this Ordinance are met, the Public Works Director shall approve the Storm Drainage Plan, inform the applicant, and issue a permit. 3. If the requirements are not met, the Public Works Director shall inform the applicant in writing and may either require additional information, or disapprove the plan. Within 21 days of the receipt of any resubmittal, the Public Works Director shall again determine if the Plan meets the requirements of this Ordinance and shall either approve or disapprove said resubmittal. 4. If the Plan is disapproved, the Public Works Director shall inform the applicant in writing of the reasons for disapproval. 5. Upon review and approval of all required plans, the Public Works Director shall approve the application, in writing, and issue the permit upon payment of any applicable fees and the provision of any required financial assurances and /or securities. 2.6 Amendment Application for amendment to a permit shall be in written and /or graphic form and may be made at any time through the same process as the original application. Until such time as an amendment is approved by the City, the storm drainage activity shall not proceed except in accordance with the Storm Drainage Permit as originally approved. 2.7 Storm Drainage Permit Fee A non refundable permit fee will be collected at the time the storm drainage plan or application for the waiver is submitted. The permit fee will provide for the cost of: plan review; administration and management of the permitting process; inspections; and, variance and appeals processing pursuant to this Ordinance. A permit fee schedule shall be established by Ordinance of City Council based on the relative complexities of storm drainage projects, and may be amended from time to time. 2.8 Storm Drainage Permit Enforcement If, through inspection or other means, it is determined that a person engaged in a storm drainage activity has failed to comply with approved Storm Drainage Plans and /or other permit conditions, any or all enforcement actions prescribed in this Ordinance may be initiated. When permit violations are identified, a written notice of violation shall be served upon that person by registered or certified mail or personal service. The notice shall set forth the measures necessary to achieve compliance with the plan, specify the time period to commence and complete corrections, and indicate the consequences for failure to correct the violation. A. Any Storm Drainage Permit issued by the City may be suspended or revoked after written notice is given to the permittee for any of the following reasons: 1. Any violation(s) of the conditions of the Storm Drainage Permit. 2. Changes in site runoff characteristics upon which a permit or waiver was granted. STORMWT9.DOC 11/21/95 12 3. Construction not in accordance with the approved plans. 4. Non compliance with correction notice(s) or "stop work" order(s) issued for the construction of temporary or permanent storm water management facilities. 5. An immediate danger to life, safety, or property exists in a downstream area or adjacent property as determined by the Public Works Director. B. In addition to the action under subsection A, the Public Works Director may post a site with a "stop work" order directing that all storm drainage activities cease immediately. The issuance of a "stop work" order may include any discretionary conditions or standard requirements of the King County Stormwater Design Manual, or city standards which must be fulfilled before work under the Storm Drainage Permit may continue. C. No work element on the approved inspection schedule shall proceed until the City inspects and approves the work previously completed and furnishes the permittee with the results of such inspection. 2.9 Inspection Requirements During Construction Regular inspections shall be made and logged by the City' s Utility Inspector (or his /her designee) at the following intervals once storm drainage construction activities have been initiated: A. Prior to clearing, filling, or grading; B. After storm events involving at least .5 inches of precipitation. C. Following installation of all temporary storm drainage facilities; D. Prior to and following installation of all permanent storm water management facilities; E. Prior to and following installation of water quality control and flow attenuation devices; F. During installation of all piping, catch basins, inlet /outlet structures, concrete, and anti -seep barriers /structures. G. Following permanent revegetation of the site. Section 3. System /Property Protection. 3.1 Determination of Risk /Hazard If the Public Works Director determines that a significant risk of accelerated erosion, off -site sedimentation, decreased water quality, or other adverse impacts exists due to permitted storm drainage activities he /she may require a revised Storm Drainage Plan. Pending the preparation of the revised plan, work shall cease or may continue under conditions prescribed by the Public Works Director. 3.2 Emergency Action Whenever the Public Works Director determines that the acts or intended acts represented in the Storm Drainage Plan constitute a hazard to life or safety, or endanger property, or adversely affect the safety, use or stability of a public way, drainage channel, or Sensitive Area or Buffer, the Public Works Director may initiate all required actions to prevent or stop any storm drainage activity. The developer or person conducting or intending to conduct such activity, upon notification by the Public Works Director shall, within the period specified therein, terminate such activities. Section 4. General Administrative Provisions. 4.1 Liability Liability for any adverse impacts or damages resulting from work performed in accordance with any permit issued on behalf of the City of Tukwila for the development of any site within the City limits, shall be the sole responsibility of the property owner. 4.2 Securities For developments which may involve a risk of property damages or possible hazards, the Public Works Director may require the provision of financial responsibility (bond, note, letter of credit, etc.) with the City to mitigate damages should they occur. The following provisions shall apply in instances where such securities are required: A. Such bond or other proof of financial responsibility shall not exceed the estimated cost of constructing and maintaining those improvements which are the source of the risk or potential hazard, provided that, in the case of storm drainage activities which do not involve expenditures at least equal to the cost of remedying the possible adverse impacts of such activities, the required financial responsibility shall be equal to City Staff s best estimate of the possible costs directly associated with remedying the adverse impacts to public or private properties not associated with the development. STORMWT9.DOC 11/21/95 13 4.3 Insurance 4.4 Variances B. The amount of any financial responsibility shall not serve as a gauge or limit to the compensation collected from a property owner as a result of damages associated with any storm drainage activity. C. Financial responsibility shall be retained until the completion of any project involving storm drainage activity or following a prescribed trial maintenance period. D. Financial responsibility will be provided in accordance with this Ordinance may be redeemed in whole or in part by the City of Tukwila upon determination by the Public Works Director that any or all of the following circumstances exist: 1. Failure on the part of the party providing such financial responsibility to fully comply, within the time specified, with approved plans and /or any corrective or enforcement actions mandated by this Ordinance; or, 2. Damages to public or property arising from the activities for which the financial responsibility was required. If, in the opinion of the Public Works Director, the risks to property or life and safety associated with a proposed development activity are substantial, said official may require the property owner to purchase liability insurance coverage in the following minimum amounts: A. Bodily injury liability $1 million per occurrence. B. Property damage liability $1 million per occurrence. The Public Works Director may require higher policy limits than set forth above in those cases where the minimum amounts are deemed insufficient to cover possible risks. All insurance policies obtained in accordance with these provisions shall name the City of Tukwila as an "additional insured" and shall be written by a company licensed to do business in the State of Washington. Neither issuance of a permit, nor compliance with these provisions or any other conditions imposed by the City relieves any person from any responsibility for damage to persons or property otherwise imposed by law, nor for damages in an amount greater than the insured amount; nor, imposes any liability upon the City for damages to persons or property arising from activities permitted by the City or otherwise undertaken by any person. The City may grant a written variance from any requirements of this Ordinance if there are exceptional circumstances applicable to the site such that strict adherence to the provisions contained herein will result in unnecessary hardship and not fulfill the purpose of this Ordinance as set forth in Section 1. A written request stating the specific variance sought and the reasons supporting the approval of such variances shall be provided to the Public Works Director. The Public Works Director shall then provide a recommendation in writing to the City Council and the Council shall make the final determination. A variance to this Ordinance shall not be granted unless all of the following criteria are met: A. Strict compliance with the provisions of this Ordinance may jeopardize project feasibility and reasonable use of property. B. Proposed drainage facilities are consistent with the purpose and intent of this Ordinance given in Section 1.1. C. The granting of the exception or standard reduction will not be detrimental to the public welfare, existing drainage systems or injurious to other property in the drainage basin. D. The recommendation of a licensed engineer supports the variance. 4.5 Permits The application for and issuance of permits as prescribed in this Ordinance shall constitute the administrative Mechanism for the enforcement of the provisions contained herein. Such permits shall be non transferable absent approval of the Public Works Director and limited in scope to the specific activities for which they are granted. 4.6 Penalties The following penalties shall be applied in whole or in part for the violation of permit conditions contained in this Ordinance or the failure to obtain permits required for activities regulated by this Ordinance. All remedies shall be considered cumulative and in addition to any other lawful action. Each day that a violation of this Ordinance is committed or permitted to continue constitutes a separate offense to which both the civil and criminal penalties set forth below shall apply. STORMWT9.DOC 11/21/95 14 4.7 Abatement Any storm drainage activity performed in violation of this Ordinance or any lawful order or requirement of the Public Works Director pursuant to this Ordinance, shall be deemed to be a public nuisance and may be abated. 4.8 Injunctive Relief A. Whenever the City has reasonable cause to believe that any person is violating or threatening to violate this Ordinance or any rule or other provisions adopted or issued pursuant to this Ordinance, it may either before or after the institution of any other action or proceeding authorized by this Ordinance, institute a civil action in the name of the City for injunctive relief to restrain the violation or threatened violation. Such action shall be brought in King County Superior Court. B. The institution of an action for injunctive relief under this section shall not relieve any party to such proceedings from any penalty prescribed for violations of this Ordinance. 4.9 Appeals The Appeals process that will be followed by any person aggrieved by the action of the City is provided under Section 8.45 of the Tukwila Municipal Code. Section 5. Severability. If any portion of this Ordinance as now or hereafter amended, is application to any person or circumstances is held invalid or unconstitutional, such adjudication shall not affect the validity of the Ordinance as a whole, or any section, provision, or part thereof not adjudicated to be invalid or unconstitutional and its application to other persons or circumstances shall not be affected. Section 6. Effective Date. This Ordinance shall take effect five (5) days from the date of publication of the attached summary which is hereby approved. PASSED BHE CITY COUNCIL OF 14E CITY OF TUKWILA WASHINGTON, at a Regular Meeting thereof this -1 day of .1995. ATTEST /AUTHENTICATED: e E. Cantu, City Clerk APPROVED AS TO FORM: By /(Vi- 2%i I r A new T.M.C. Section 14.28.080 is hereby created to read as follows: A. Civil Penalties 1. The violation of or failure to comply with any order or requirement made in accordance with the provisions of this Ordinance is a civil violation. The provisions of T.M.C. Chapter 8.45 shall be used to enforce this chapter. 2. It shall not be a defense to the prosecution for failure to obtain a permit required for this Ordinance, that a contractor, subcontractor, person with responsibility on the site, or person authorizing or directing the work, erroneously believed a permit had been issued to the property owner or any other person. Office of the City Attorney FILED WITH THE CITY CLERK: ///,-0/ 1 PASSED BY THE CITY COUNCIL: 1 7,2/¢ J0 PUBLISHED:A2 95 'S� EFFECTIVE DA E: /a. /Sfl$ ORDINANCE NO.: 75 1 W. Rants, Mayor STORMWT9.DOC 11/21/95 15 CITY OF TUKWILA SUMMARY OF ORDINANCE NO. AN ORDINANCE OF THE CITY OF TUKWILA, WASHINGTON, RELATING TO SURFACE AND STORM WATER MANAGEMENT; AMENDING ORDINANCE 1523 AND CREATING TMC SECTION 14.28.080 TO ESTABLISH PENALTIES AND PROCEDURES FOR CHAPTER VIOLATIONS; PROVIDING FOR SEVERABILITY; AND ESTABLISHING AN EFFECTIVE DATE. On 211t the City Council of the City of Tukwila passed Ordinance No. 2 S` setting forth rules, regulations, and processes to control storm drainage activities in the City of Tukwila; providing for severability, and establishing an effective date. The full text of this ordinance will be mailed without charge to anyone who submits a written request to the City Clerk of the City of Tukwila for a copy of the text. APPROVED by the City Council at its meeting of /a- 1 Published Seattle Times: /02/ g /7,T y_e Itt4we rfer_4-c-(6L- ane E. Cantu, City Clerk