1.2.5
1.2.5.1 Single Family Residential Subdivision Design
Single family residential subdivision lot development design shall also address the following requirements:
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For each lot, a minimum design assumption for hard surfaces and developed pervious surface shall be determined as part of the overall drainage design.
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The minimum design assumptions per lot shall be stated on the face of the SDAP plans and on the face of the final plat (see Vol II–1.4.6 Single-Family Residential Subdivision Design Submittals).
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If surplus stormwater mitigation is provided for the subdivision to allow flexibility in individual lot design, that surplus availability shall be stated in square feet on the face of the final construction drawings and final plat. Usage of the surplus area by individual lot development may be considered when the design does not cause noncompliance with any conditions of subdivision approval or other applicable regulations.
1.2.5.2 Additional Design Requirements
This manual presents Kitsap County’s minimum standards for engineering and design of drainage BMPs. While Kitsap County believes these standards are appropriate for a wide range of project proposals, compliance solely with these requirements does not relieve the professional engineer submitting designs of their responsibility to ensure drainage facilities are engineered to provide adequate protection for natural resources and private property.
Compliance with the standards in this manual does not necessarily mitigate all probable and significant environmental impacts to aquatic biota. Fishery resources and other living components of aquatic systems are affected by a complex set of factors. While employing a specific flow control standard may prevent stream channel erosion or instability, other factors affecting fish and other biotic resources (e.g., increases in stream flow velocities) are not directly addressed by this manual. Likewise, some wetlands, including bogs, are adapted to a very constant hydrologic regime. Even the most stringent flow control standard employed by this manual does not prevent all increases in runoff volume, and it is known that increased runoff can adversely affect wetland plant communities by increasing the duration and magnitude of water level fluctuations. Thus, compliance with this manual should not be construed as mitigating all probable and significant stormwater impacts to aquatic biota in streams and wetlands; additional mitigation may be required.
Additional mitigation may also be required to compensate for loss of critical drainage area habitat functions associated with activities inside the critical drainage area or critical drainage area buffers.