9307 18TH AVE W 2025-04-18 - Laserfiche WebLink

this property is forested, with shrubs and herbaceous plants in the understory. This vegetation allows for infiltration and absorption of precipitation. The on-site forested buffer does provide a high level of water quality benefit. Hydrologic functions Stream buffers help to moderate water level fluctuations. Buffer vegetation impedes the flow of runoff, increases the humus content of soil (greater adsorption capacity), and preserves soil composition as intense rainfall hits the ground. The sloped nature of the buffer and herbaceous areas limit the capacity of the buffer to perform this function. Overall, the forested buffer with its dense vegetation performs this function at a moderate to high level. Wildlife Habitat Healthy vegetation within the stream corridor, specifically along banks and within the floodplain, help maintain wildlife habitat function within and adjacent to streams. Riparian vegetation provides many crucial aspects of healthy fish habitat including shade, bank stabilization, nutrient cycling, pollutant removal and input of large woody debris (LWD) in the channel. LWD is especially important since it facilitates the formation of important habitat features like pools through bed scour, and it buffers the severity of sedimentation and erosion. Vegetated stream buffers also provide benefits to terrestrial wildlife including, refuge/cover, nesting, foraging, and resting habitat. 7.2 POST-CONSTRUCTION FUNCTIONS AND VALUES To compensate for the removal of vegetation along the stream bank and buffer, mitigation via buffer restoration is proposed. Restoration of the cleared area with native plantings will re-establish the functionality of this portion of buffer to its original forest and shrub state. Buffer restoration will maintain quantity, density, and structural diversity of the native plant assemblage as the adjacent buffer area, thereby maintaining the attenuation of floodflow, biofiltration function, and the quality of wildlife habitat provided. This mitigation strategy thereby results in no net loss of functions and values for the buffer area and associated stream. 8.0 CITY OF EVERETT CRITICAL AREA PROTECTIONS 8.1 CRITICAL AREA PERMANENT PROTECTION Critical areas and associated buffers within the City of Everett shall be placed in protective Critical Area Covenants or Critical Area Tracts, as determined by EMC 19.37.220 (see below). The covenant or tract shall be filed on record with the Snohomish County Auditor. A. Critical Area Covenants. Except as providedfor below, the city shall require that allfeatures classified as critical areas by this chapter and their buffers be placed in critical area protective covenants. Covenants shall not be required for: 1. Utility and road projects in public rights-of-way. 2. Utility and road projects on private easements where the proponent does not own the land. Talley - 18th Ave W 16 Critical Area Study and Buffer Restoration Plan WRI#19238 November 6, 2019