LID Code Consistency Amendments Ordinance #7 CITY OF MOUNTLAKE TERRACE ORDINANCE NO.

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1 CITY OF MOUNTLAKE TERRACE ORDINANCE NO. AN ORDINANCE OF THE CITY OF MOUNTLAKE TERRACE, WASHINGTON, IMPLEMENTING LID BY AMENDING MOUNTLAKE TERRACE MUNICIPAL CODE SECTION PERTAINING TO DRAINAGE STANDARDS; AMENDING SECTION PERTAINING TO STORMWATER DESIGN AND MAINTENANCE STANDARDS; AMENDING SECTION PERTAINING TO TREE REMOVAL PENALTIES; AND AMENDING SECTION PERTAINING TO NOTICE PROVISIONS FOR LID VARIANCE WHEREAS, urbanization has led to increased impervious surface areas and reduced tree canopy coverage, resulting in increased surface water runoff and less percolation to groundwater aquifers. These conditions have caused the transport of pollutants to downstream receiving waters; and WHEREAS, the City of Mountlake Terrace has authority to proactively manage stormwater within its jurisdiction under the National Pollution Elimination Discharge System (NPDES) Permit for Phase II Cities; and WHEREAS, the NPDES Permit is administered by the Washington State Department of Ecology with the intent of achieving the Federal Clean Water Act of 1972 goal of ensuring that all public waters are fishable and swimmable; and WHEREAS, the Department of Ecology is requiring all Western Washington cities to review, revise and make effective local development-related codes, rules, standards, or other enforceable documents to incorporate and require LID principles and LID BMPs to be in compliance with the National Pollution Elimination Discharge System (NPDES) Permit for Phase II Cities; and WHEREAS, Low Impact Development, which calls for infiltrating water at or near its source, is recognized by the Washington State Department of Ecology as being better able to control surface water runoff and control for fluctuations in water than more traditional methods of stormwater management; and WHEREAS, the City Council intends to comply with the NPDES Permit by adopting the proposed code updates; and WHEREAS, the City of Mountlake Terrace has developed standards that implement a new approach to managing rainwater and urban runoff while mitigating the negative impacts of development and urbanization; and

2 Page 2 of 8 WHEREAS, the city has drafted, and is concurrently processing, standards to implement LID; and WHEREAS, the purpose of this ordinance is to update related sections of the municipal code to implement and be consistent with standards drafted and concurrently being processed pertaining to LID, including storm drainage design standards, stormwater design and maintenance standards, and LID variance notice requirements; and WHEREAS, the provisions of this ordinance are consistent with provisions in the Vision for the Mountlake Terrace Town Center as adopted in 2007 and amended in 2009 and 2016, and will ensure proper balance between LID and Town Center objectives; and WHEREAS, Ordinance No adopted by reference the Department of Ecology s 2012 Stormwater Management Manual for Western Washington, and the Department of Ecology has since provided a newer manual; and WHEREAS, the City Council intends that the most recent Stormwater Manual should be used in the regulation of development; and WHEREAS, this Ordinance has the effect of adopting by reference the most recent version of the Department of Ecology s Stormwater Management Manual for Western Washington; and WHEREAS, State Environmental Policy Act (SEPA) review was performed on the proposed amendment and a Determination of Non-significance (DNS) was issued on October 7, 2016, which has not been appealed; and WHEREAS, in accord with the requirement set forth in RCW 36.70A.106, the City provided the Washington State Department of Commerce notice of the City s intent to adopt the proposed ordinance on October 19, 2016 for its 60-day review and comment period; and WHEREAS, the Planning Commission held a public hearing on the proposed amendments on November 14, 2016 and has forwarded a recommendation to the City Council to approve the proposed amendments; and WHEREAS, the City Council held a public hearing on the proposed amendments on December 19, 2016, considered the proposed code amendment and the entire record, including recommendations from the Planning Commission, and found the proposal to be consistent with the Growth Management Act; and WHEREAS, the City Council finds that the proposed regulations will make LID the preferred and commonly used method for stormwater management within the City, as required by the Department of Ecology; and WHEREAS, the City Council finds that the proposed amendments are consistent with the City s Comprehensive Plan and other goals and objectives of the City; and 2

3 Page 3 of 8 WHEREAS, the Growth Management Act of the State of Washington (GMA) contains goals and requirements, such as consistency with the local Comprehensive Plan, that pertain to zoning code amendments and the proposed zoning code amendments in this ordinance are consistent with the GMA; and WHEREAS, the adoption of this Ordinance will promote the public health, safety, and general welfare within the City of Mountlake Terrace. NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF MOUNTLAKE TERRACE, WASHINGTON DOES ORDAIN AS FOLLOWS: Section 1. Recitals. The Recitals set forth above are hereby adopted and incorporated as Findings of Fact and/or Conclusion of Law of the City Council. The City Council bases its findings and conclusions on the entire record of testimony and exhibits, including all written and oral testimony before the Planning Commission and the City Council. Section 2. Amendment. Section of the Mountlake Terrace Municipal Code is Low impact development (LID) Alternative drainage standards. A. Low impact development BMPs are an alternative to preferred over conventional stormwater management systems that rely on detention structures and closed conveyance systems. Use of LID BMPs may reduce or eliminate the need for conventional detention facilities but does not remove the obligation to comply with the minimum requirements of the Stormwater Manual. A variety of BMPs to minimize impervious surfaces and to manage stormwater has been developed and tested for use in western Washington. B. The menu of LID BMPs identified in the technical guidance manual are accepted for use in stormwater site plans to address the minimum requirements for flow control and runoff treatment in the Stormwater Manual, subject to the specifications, performance standards, and design criteria in the technical guidance manual and subject to review and approval under this chapter by the Director. C. The City of Mountlake Terrace encourages requires the use of low impact development techniques where feasible, reasonable and appropriate as described in Chapter MTMC and other applicable codes, unless determined to be infeasible through the infeasibility criteria listed in the Stormwater Manual or by the City Engineer. Where low impact development BMPs are proposed for installation, the BMP selection criteria, BMP the design criteria, the BMP infeasibility criteria, LID competing needs criteria, and BMP limitations in the technical guidance Stormwater manual shall apply. D. Restrictions on conversion of drainage facilities associated with subdivision plats shall be recorded on the face of the plat. A covenant shall be recorded with the Snohomish County Auditor s Office for each lot containing or served by bioretention facilities in a form approved by the City Attorney. The covenant shall identify requirements and liability for preservation and maintenance of low impact development facilities approved under this chapter and privately held in individual or undivided ownership or intended for public ownership. 3

4 Page 4 of 8 Section 3. Amendment. Section of the Mountlake Terrace Municipal Code is Standards. A. The Stormwater Manual, as defined in this chapter, is adopted and by this reference made a part of this chapter as though fully set forth herein; provided, that certain parts of Volume 1, Chapter 2 of the Stormwater Manual shall be replaced as set forth in subsection B of this section. B. Appendix 1 of the National Pollution Discharge Elimination System (NPDES) permit issued by the Department of Ecology to cover the City of Mountlake Terrace is adopted as though fully set forth herein including and the thresholds, definitions, minimum requirements and exceptions, adjustment and variance criteria that it contains shall replace the corresponding requirements of Volume 1, Chapter 2 of the Stormwater Manual. C. The standards set out in MTMC shall apply to all projects subject to this chapter. Additionally, the water quality standards shall apply to all properties discharging storm and surface water runoff into the drainage system. Except where specifically described, it shall be the developer s responsibility to determine the method of compliance with the standards. Section 4. Amendment. Section of the Mountlake Terrace Municipal Code is General design, construction and maintenance standards. The following design requirements shall apply to all projects and are intended to be consistent with the relevant comprehensive drainage management plan and stormwater comprehensive plan: A. Mandatory Requirements. 1. Surface water entering the subject property shall be received at the naturally occurring location and surface water exiting the subject property shall be discharged at the naturally occurring location to the maximum extent practicable as determined by the Director with adequate energy dissipaters within the subject property to minimize downstream damage (and with no diversion at any of these points). 2. Where open channel construction is used to handle drainage within the subject property, and where LID BMP s cannot otherwise be used to handle drainage, the following standards shall apply: a. A minimum of 15 feet will be provided between any structures and the top of the bank of the defined channel. b. In open channel work the water surface elevation will be indicated on the plan and profile drawings. The configuration of the finished grades constituting the banks of the open channel will also be shown on the drawings. c. Proposed cross section of the channel will be shown with stable side slopes as approved by the Department. d. The water surface elevation of the flow for the design storm will be indicated on the cross section. 3. When a closed system is used to handle drainage within the subject property, the system will be a minimum of 10 feet from all structures divided into multiple ownerships except structures divided under the provisions of either Chapter or RCW (Horizontal Property Regimes Act and Condominium Act, respectively). 4

5 Page 5 of 8 4. All drainage easements granted to the City within the subject property shall be at least 20 feet in width for operation and maintenance of open-channel or closed-system installation. 5. Open retention/detention ponds and infiltration facilities serving private or commercial property shall not be located in dedicated public road right-of-way areas unless they are part of a comprehensive LID approach to stormwater design for the abutting site and associated right-ofway, and unless specifically allowed by the Director. 6. An emergency overflow system is required for all retention/detention and infiltration facilities. 7. Stormwater retention/detention shall not occur on asphalt, graveled or concrete surfaces except those permeable surfaces that are part of an LID stormwater design as approved by the Director. 8. Where drainage facilities discharge to natural drainage ways or watercourses or both, energy dissipation facilities as approved by the Director shall be provided to minimize erosion and deterioration of the streambed or banks. B. Infiltration and Evapotranspiration. A balance of infiltration Infiltration of stormwater into the ground and evapotranspiration into the air is encouraged required to the maximum extent practicable. Infiltration and evapotranspiration potential for all projects other than single-family construction not reviewed as part of a plat or short plat shall be reviewed according to the requirements of Chapter and the Stormwater Manual and shall be approved by the Director prior to any attempt to infiltrate to the ground. Approved infiltration projects shall have an inflow capacity sufficient to handle the design storm. An overflow system which meets the water quality and quantity release standards shall be available for backup. The approval of any infiltration project shall not constitute approval of any means by which unstable subsurface conditions may occur; such conditions resulting from infiltration projects not constructed by the City shall remain the responsibility of the developer. C. Construction and Maintenance. Construction materials and methods shall be in accordance with the Standards and Specifications for Municipal Public Works Construction prepared by the American Public Works Association, latest edition, unless otherwise approved by the City. Copies of this publication are available for public inspection at the office of the Department. Maintenance methods shall be in accordance with the Stormwater Manual. D. Discharge to Natural Drainage Ways. Where drainage facilities discharge to natural drainage ways or watercourses, energy dissipation facilities shall be provided to prevent erosion and deterioration of the streambed or banks. Energy dissipation facilities shall be constructed of approved materials. Material such as broken concrete slabs, pipe, tires, scrap metal or debris are prohibited. No person shall discharge drainage waters from their project to any point or in any manner not approved by the City. Prior to occupancy of the site or any related structure, permanent erosion control facilities must be established and operating at designed efficiency. E. Detention Facilities. All detention facilities shall be designed in such a manner that the outlet structures are easily accessible for inspection, testing, and maintenance. The release of runoff from the storage basin shall be through a weir, orifice, grate, pipeline, or any other structure or LID system approved by the Director and shall be maintained by the owner at his expense unless accepted for maintenance by the City as provided for under MTMC Where detention facilities are incorporated into the property development in the form of lakes or fountains, they shall be designed so as to avoid algae blooms and prevent stagnation. This 5

6 Page 6 of 8 area of concern shall be addressed in the permit application and may include requirements for maintenance. All open detention facilities not incorporated into landscaping arrangements shall not retain water for more than 48 hours. F. Wetlands. Where existing wetlands function as a control feature in the natural drainage system, no project will be permitted which reduces that control feature. Specific project requirements near wetlands shall be regulated under Chapter MTMC, Critical Areas. G. Development in areas where the 100-year flood plain has been established by a comprehensive drainage plan (Halls, Lyon and McAleer basins), or by flood insurance rate maps, or that are considered to be frequently flooded areas per Chapter MTMC, or where the Community and Economic Development Department has determined that drainage or erosion conditions present an imminent potential of harm to the welfare and safety of the surrounding community shall meet special drainage conditions set by the Department. Conditions may include the limitation of the volume of discharge from the developed property to be predevelopment levels, preservation of wetlands or other natural drainage features, or other controls necessary to protect against a community hazard. Due to the detrimental effect on upstream and downstream properties, no filling, grading or construction shall take place within the established flood plains where an equal amount of displaced flood water storage has not been provided elsewhere. The developer must provide information, plans and calculations to satisfy the Director that development within the flood plains is not detrimental by increasing the flooding occurring upstream or downstream from the site. H. Use of Storm and Surface Water Runoff. 1. Drawdown. Storm and surface water runoff may be drawn in any quantity from manmade storage devices on private property which release directly into the drainage system or which are completely enclosed. No water may be drawn from the watercourses, sloughs, streams, ponds, lakes, or swamps that make up the public drainage system except under the provisions of approved state water rights permits. 2. Permitted Uses. Storm and surface water runoff that can legally be drawn off from the project area may be used for any nonpotable purposes. The distribution system employed shall be separate from the City water system. I. Fish Passage. All projects involving perennial streams shall make adequate accommodation for fish passage. No obstructions of any kind shall be placed within the stream which would prohibit the free passage of fish under all flow conditions. Section 5. Amendment. Section of the Mountlake Terrace Municipal Code is Cumulative civil penalty. In addition to or as an alternative to any other penalty provided herein or by law, any developer/owner who violates the provisions of this chapter or an approved drainage plan shall incur a cumulative civil penalty in the amount of $ per day from the date set for correction, pursuant to MTMC , until the violation is corrected, except that the removal of significant trees as defined in MTMC without an approved clearing and grading permit under the provisions of Chapter shall be subject to monetary penalties as follows: 1. Monetary penalties shall be the greater of: a. Two hundred dollars for each significant tree cleared, cut, damaged or removed; or 6

7 Page 7 of 8 b. The value of each significant tree cleared, cut, damaged or removed, the value to be the replacement value as determined under the methods described in the Guide for Establishing Value of Trees and Other Plants, published by the International Society of Arboriculture, now or as hereafter amended. 2. Each significant tree removed in violation Chapter and Chapter is a separate violation, subject to separate penalties. Section 6. Amendment. Section of the Mountlake Terrace Municipal Code is Administrative approvals without notice. A. The Director, in consultation with the City Engineer, may approve, approve with conditions or deny the following without notice: 1. Lot line adjustment. 2. Lot consolidation. 3. Time extension. 4. Minor amendments or modifications to approved developments or permits. Minor amendments are those which may affect the precise dimensions or location of buildings, accessory structures and driveways, but do not: a. Affect overall project character; b. Increase the number of lots, dwelling units, or density; c. Decrease the quality or amount of open space; or d. Impact ability of the project to meet the requirements of City codes and ordinances except as permitted under original approval. 5. LID Variances pursuant to MTMC B. The Director s decisions under this section shall be final on the date issued. Section 7. Corrections. The City Clerk and codifiers of the ordinance are authorized to make necessary corrections to this ordinance including, but not limited to, the correction of scrivener/clerical errors, references, ordinance numbering, section/subsection numbers and any references thereto. Section 8. Severability. If any section, subsection, paragraph, sentence, clause or phrase of this ordinance is declared unconstitutional or invalid for any reason, such invalidity shall not affect the validity or effectiveness of the remaining portions of this ordinance. Section 9. Publication and Effective Date. This Ordinance, or a summary thereof consistent of the title, shall be published in the official newspaper of the City and shall take effect and be in full force five (5) days after its adoption and publication as required by law. PASSED BY THE CITY COUNCIL OF THE CITY OF MOUNTLAKE TERRACE this day of, 2016 and signed in authentication of its passage this day of,

8 Page 8 of 8 Mayor Jerry E. Smith ATTEST: City Clerk APPROVED AS TO FORM: Gregory G. Schrag, City Attorney 8