Environmentally Critical Areas | Environment & Sustainability
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 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; and d) The wetland 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. v. 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. vi. Use of pervious material for driveway/road construction: up to 10 percent reduction in standard buffer width. vii. Restoration of on-site buffer and wetland areas, or restoration of off-site buffer and wetland areas
within the same sub-basin of the impacted wetland if no on-site restoration is possible: a) Up to 10 percent reduction in standard buffer width if restoration area is at a 2:1 ratio or greater; or b) Up to 20 percent reduction in standard buffer width if restoration area is at a 4:1 ratio or greater. viii. Removal of significant refuse or sources of toxic material: up to 10 percent reduction in standard buffer width. ix. Percentages listed above may be added together to create a total buffer reduction; provided, that the total reduction does not exceed 50 percent of the standard buffer width. j. The use of hazardous substances, pesticides and fertilizers in the wetland and its buffer may be prohibited by the City. k. The introduction of livestock into a wetland or wetland buffer is prohibited.
2. Wetlands – Permitted alterations
Alterations to wetlands and wetland buffers are not allowed, except as provided for by complete exemptions, allowances for existing urban development and other uses and exceptions in this chapter or as allowed for by this section. a. Alterations may be permitted if the department determines, based upon its review of critical areas
Effective | January 1, 2022
Title 21: Sammamish Development Code | 97
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