Resolution 2694 - Laserfiche WebLink

• EXHIBIT: From " uohomish County Paine Field Area .,omprehensive Plan" Environmentally Sensitive Areas This plan uses an overlay (Figure 10) to designate environmentally sensitive areas. Three different criteria were used to define these areas: steep slopes, wet soils, and proximity to streams, lakes, shorelines and wetland areas. As illustrated on Figure 10, most of the steep slopes (those in excess of 15%) are associated with the bluffs overlooking Puget Sound to the west of the airport. Development on these slopes and elsewhere will be carefully controlled by the county's slope policy to avoid slide hazards, erosion problems, and loss of wildlife habitat. The slope policy was adopted by resolution on April 2, 1979 as an amendment to the county-wide comprehensive plan. A second criterion used to define environmentally sensitive areas is wet, highly organic soils. These soils are generally found in basins and the flat bottomlands associated with streams and lakes. They are characteristically the soils which form around the swamps and marshes at the headwaters of stream systems like Swamp Creek. These wet organic soils have high water holding capacity and store moisture' during the rainy season for gradual release during the drier months,. Consequently, these soils are vital to healthy streams flowing year around. The U.S. Soil Conservation Service (SCS) has identified the following list of soil types as wet, organic soils characteristic of wetlands and stream corridors. Consequently, these soil types have been mapped for the PFPA (Figure 10) to identify environmentally sensitive lands in the Swamp Creek basin where development may be prohibited or somewhat restricted in an effort to preserve a viable Swamp Creek system. Table 7 PFPA Environmentally Sensitive Soils 130 Bellingham Silty Clay Loam 188 Hale (Norma) Silt Loam 220 Mc Kenna Fine Silt Loam 240 Norma File Silt Loam 430 Mukilteo Peat 350 Shales (duck (Terric Medioprist) 120 Alderwood Everett 25-70% slope 186 Everett Gravelly Silt Loam 15-25% slope 107 Alderwood Gravelly Silt Loam 15-25% slope A third criterion used to describe a sensitive environment is proximity to water bodies. As an earlier discussion points out, stream corridors and lake fronts are sensitive even where there are no wet soils or steep slopes. Erosion, runoff, non-point pollution, and temperature changes are all associated with poorly designed land development too close to streams and lakes. To avoid or minimize these problems, all property within 200 feet of either side of a stream or a shoreline is designated environmentally sensitive. 3