The standards in this article shall apply to all projects subject to the rules and regulations described herein. Additionally, the water quality standards and sedimentation control standards should apply to all properties discharging storm and surface water runoff into the drainage facility. All standards including but not limited to conveyance, retention, stormwater quality, flow control and maintenance contained in the Design Manual are hereby adopted by reference and amended as follows:
A. 
Drainage review threshold for all projects shall be reduced from 2,000 square feet to 1,000 square feet;
B. 
The entire corporate limits of the city of Lake Forest Park are within the conservation flow control area;
C. 
The city of Lake Forest Park is within the basic water quality area with enhanced treatment required for multifamily and commercial as identified in the Design Manual;
D. 
The sensitive area mapping shall be the mapping referenced in LFPMC § 16.16.050; and
E. 
The impervious surface area percentage exemption in Section 1.2.3 is not applicable within the city of Lake Forest Park.
(Ord. 427 § 10, 1989; Ord. 481 § 1, 1991; Ord. 730 § 6, 1997; Ord. 956 § 5, 2007; Ord. 1012 § 2, 2010)
A. 
Recharge of stormwater into the ground is encouraged in areas with appropriate soils; however, recharge potential shall be reviewed and certified by the city engineer prior to any attempt to recharge to the ground. Approved recharge 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.
B. 
The approval of any recharge project shall not constitute approval of any means by which unstable subsurface conditions may occur; such conditions resulting from recharge projects not constructed by the city shall remain the responsibility of the developer.
(Ord. 427 § 10.1.2, 1989)
Construction materials and methods shall be in accordance with "Standards and Specifications for Municipal Public Works Construction" prepared by the American Public Works Association, latest edition, unless otherwise approved by the city engineer. Copies of this publication are available for public inspection at the office of the city.
(Ord. 427 § 10.1.3, 1989)
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 matter not approved by the city. Prior to occupancy of the site or any related structure, permanent erosion control must be established and operating at designed efficiency as approved by the city engineer.
(Ord. 427 § 10.1.4, 1989)
The owner shall be responsible for maintaining all storage basins, and for providing for the safety of the public as related to the storage basins. The city reserves the right to inspect such facilities at any time and upon written notice by the city to the owner that the basin has been filled in to the point where the design capacity is no longer available, or the outlet structure is clogged or blocked, or in some other manner is not functioning as designed and approved, the owner shall correct the problem. If the owner fails to respond to the written notice within fifteen days, the city may undertake the work and bill all time and material to the owner.
(Ord. 427 § 10.1.5, 1989; Ord. 730 § 8, 1997)
A. 
Where existing wetlands function as a control feature in the natural drainage system, no project will be permitted which reduces that control feature. Projects proposed in a wetland area shall be accompanied by an engineering report prepared by a registered civil engineer qualified to practice in the state of Washington, describing existing conditions and how those conditions will be maintained during and after project completion. Projects that meet the threshold requirements in core requirement No. 3, flow control, and core requirement No. 8, water quality, that discharge stormwater to a wetland either directly or indirectly through a conveyance system shall also meet the following requirements:
1. 
Discharges to wetlands shall maintain the hydrologic conditions, hydrophytic vegetation, and substrate characteristics necessary to support existing and designated uses. The hydrologic analysis shall use the existing land cover condition to determine the existing hydrologic conditions unless directed otherwise by the director. A wetland can be considered for hydrologic modification and/or stormwater treatment in accordance with Guide Sheet 1B in Appendix I-D of the Department of Ecology Stormwater Management Manual for Western Washington (2005). Stormwater treatment and flow control facilities shall not be built within a natural vegetated buffer, except for:
a. 
Necessary conveyance systems as approved by the director; or
b. 
As allowed in wetland approved for hydrologic modification and/or treatment in accordance with Guide Sheet 1B in Appendix I-D of the Department of Ecology Stormwater Management Manual for Western Washington (2005).
B. 
No construction shall be permitted within 50 feet of the average annual high water line of a wetland unless permitted under LFPMC § 16.16.330.
(Ord. 427 § 10.1.6, 1989; Ord. 730 § 9, 1997; Ord. 1012 § 3, 2010)
A. 
Development in areas where the 100-year floodplain has been established by a comprehensive drainage plan (Lyon and McAleer basins studies or the sensitive areas ordinance/maps or as may be further defined by any future comprehensive drainage plan adopted by the city), or where the city engineer 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 city. Conditions may include the limitation of the volume of discharge from the developed property to the predevelopment levels, preservation of wetlands or other natural drainage features, or other controls necessary to protect against a community hazard.
B. 
Due to the detrimental effect on upstream and downstream properties, no filling, grading or construction shall take place within the established floodplains where an equal amount of displaced floodwater storage has not been provided elsewhere. The developer must provide information, plans and calculations to satisfy the city engineer, that development within the floodplains is not detrimental by increasing the flooding occurring upstream or downstream from the site.
(Ord. 427 § 10.1.7, 1989)
A. 
The storm and surface waters discharging from an individual property or project shall be of such quality as meet Class A water quality standards of the state of Washington (Chapter 173-201 WAC) herein adopted as part of this chapter by reference or the quality of the receiving water, whichever is higher. No activity shall introduce into the drainage waters any liquid or solid foreign substances of biodegradable or other nature which shall cause the water quality in the receiving water to violate applicable state standards. Products of erosion shall be prevented from entering the natural drainage system at all times, during both the construction on the property and the subsequent operation of the facilities provided. All trash and debris shall be prohibited from entering the drainage system at any point within the property.
B. 
It shall be prohibited and in violation of this chapter for any person to:
1. 
Cause or permit litter, trash, rubbish or debris to enter the drainage system of the city;
2. 
Cause or permit liquid or water-carried pollutants to enter the drainage system of the city including but not limited to oils and petroleum products, paints and paint thinners, pesticides, fertilizers, soaps, detergents and washing wastes;
3. 
Cause or permit horses, cattle or other domestic livestock to enter any watercourses or wetlands that are part of the drainage system of the city. Stables, pastures and other animal enclosures shall be drained so as to prevent polluted drainage waters from entering the drainage system of the city;
4. 
Cause or permit grading, clearing, filling or other land surface changes to take place in such a way as to allow drainage from the property to carry any suspended or dissolved matter into the drainage system of the city;
5. 
Cause or permit to take place in the streams, watercourses or wetlands that are part of the drainage system any work that would result in the transmission of silt, pollutants, or other, foreign substances from one part of the system to another;
6. 
Discharge any waters that would, in any way, alter the temperature of the nearest receiving waters.
(Ord. 427 § 10.2.1, 1989)
A. 
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, streams, ponds, lake or swamps that make up the public drainage system except under the provisions of approved state water rights permits.
B. 
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.
(Ord. 427 § 10.2.3, 1989)
All projects involving perennial streams shall make adequate accommodation for fish passage, as approved by Washington State Department of Fisheries and Game. No obstructions of any kind shall be placed within the stream which would prohibit the free passage of fish under all flow conditions.
(Ord. 427 § 10.2.4, 1989)
A. 
When a project involves clearing of land, operations shall be conducted so as to expose the smallest practical area of soil to erosion for the least possible time during construction. Erosion control measures shall be undertaken prior to the time of beginning of clearing. The city may prohibit all clearing and grading during the wet season from October to May or at any other time at the discretion of the city engineer.
B. 
Vegetation shall be restored or control measures instituted at the earliest possible date, with bare soil exposure limited to no more than 30 days on slopes with sufficient grade to allow scouring of silt-size particles. At that time, erosion control measures are to be fully implemented and effective.
C. 
Where the city engineer determines that the hazard is minimal or the control program is highly reliable, the time of exposure may be extended in writing from 30 to no more than 120 days.
(Ord. 427 § 10.2.5, 1989)
In the event that the property owner shall violate any of the provisions of Appendix D of the Design Manual, the city may take immediate action to correct the problem and prevent erosion. Notice shall be in writing by mail, messenger and/or by posting on the property with the development permit. All costs associated with this corrective action shall be borne by the property owner together with any penalties adjudged under Article X of this chapter.
(Ord. 427 § 10.2.6, 1989; Ord. 730 § 11, 1997; Ord. 956 § 6, 2007)