Environmentally Critical Areas | Environment & Sustainability
and/or enhanced wetlands, or ponds supplemental to existing storm drainage and water quality requirements.
buffer is restored according to a City-approved restoration plan to improve wetland buffer functions; and c) Native tree or shrub vegetation covers less than 25 percent of the total buffer area and the area will be revegetated according to a City-approved restoration plan with native trees and shrubs to replace impacted buffer functions; and d) The stream buffer has slopes of less than 25 percent; and e) The buffer reduction determination and percentage shall be on a site-by-site basis based on the applicant’s plan and demonstration of improvement to water quality and habitat functions.
ii. Removal of existing impervious surfaces:
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 stream and buffer vegetation if the following conditions are present and/or attainable as a result of action: a) An undisturbed vegetated buffer is preserved in the remaining buffer width; and b) Existing buffer conditions are degraded such that more than 40 percent of the buffer is covered by nonnative/invasive plant species and the
v. In-stream habitat enhancement:
a) Up to 20 percent reduction in standard buffer width for log structure placement, bioengineered bank stabilization, or culvert removal; or b) Up to 30 percent reduction in standard buffer width for improving fish passage and/or creation of side channel or backwater areas. vi. If not already required under an existing development proposal, installation of oil/water separators for storm water quality control: up to 10 percent reduction in standard buffer width.
Effective | January 1, 2022
Title 21: Sammamish Development Code | 115
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