Environment & Sustainability | Environmentally Critical Areas
a) Habitat complexity, connectivity and biological functions; b) Seasonal hydrological dynamics as provided in the adopted surface water design manual;
i. Up to 20 percent reduction in the standard buffer width may be allowed if water quality is improved in excess of the requirements of the adopted surface water design manual and SDC 21.03.050, Surface Water Management, through the use of created and/or enhanced wetlands, or ponds supplemental to existing storm drainage and water quality requirements.
c) Sediment removal and erosion control;
d) Pollutant removal;
e) Large wood debris (LWD) recruitment;
ii. Removal of existing impervious surfaces:
f) Water temperature;
a) Up to 10 percent reduction in standard buffer width if impervious surfaces within the to-be- remaining buffer area are reduced by at least 50 percent; or b) Up to 20 percent reduction in standard buffer width if the to-be-remaining buffer area is presently more than 50 percent impervious and all of it is to be removed. iii. Removal of invasive, nonnative vegetation: up to 10 percent reduction in standard buffer width for the removal and extended (minimum five-year) monitoring and continued-removal maintenance of relatively dense stands of invasive, nonnative vegetation from significant portions of the remaining buffer area. iv. Restoration, preservation and maintenance of the existing wetland and buffer vegetation if the following conditions are present and/or attainable as a result of action:
g) Wildlife habitat; and
h) Microclimate.
i. Buffer Reduction. Buffers may be reduced when buffer reduction impacts are mitigated and result in equal or greater protection of the wetland functions. Prior to considering buffer reductions, the applicant shall demonstrate application of mitigation sequencing as required in SDC 21.03.020M. A plan for mitigating buffer-reduction impacts must be prepared using selected incentive-based mitigation options from the list below. The following incentive options for reducing standard buffer widths shall be considered cumulative up to a maximum reduction of 50 percent of the standard buffer width. In all circumstances where a substantial portion of the remaining buffer is degraded, the buffer reduction plan shall include replanting with native vegetation in the degraded portions of the remaining buffer area and shall include a five-year monitoring and maintenance plan.
96 | Title 21: Sammamish Development Code
Effective | January 1, 2022
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