10412 ROSEWOOD AVE ROSEWOOD PARK WHOLE SITE DEVELOPMENT 2017-04-07

permanently or periodically saturated soils of sufficient duration to exert a controlling influence on the plant species present. One of the most common indicators for hydrophytic vegetation is when more than 50 percent of a plant community consists of species rated "Facultative" and we[ter on lists of plant species that occur in wetlands. Soil Criteria and Mapped Description The Washington State Wetlands Identification and Delineation Manual, 1997 edition, defines hydric soils as those that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part. Field indicators are used for determining whether a given soil meets the definition and criteria for hydric soils. The soils underlying the site are mapped in the Soil Survey of Snohomish County Area Washington as Alderwood Urban Land Complex. Alderwood Urban Land Complex. 2 to S percent slopes, is defined as moderately deeF over a hardpan and moderately well drained. This soil formed in glacial till. The surface layers are described as very dazk. grayish brown, gravelly, sandy loam about 7 inches thick. The upper part of the subsoil is dark yellowish brown, and dark brown, very ;ravelly, sandy loam about 23 inches thick. Permeability of this soil is moderately rapid above the hardpan (< 20-40") and very slow through it. Available water capacity is low. Hydrology Criteria The Washin�ton State Wetlands Identification and Delineation Manual, 1997 edition, states that "areas which are seasonally inundated and/or saturated to the surface for a consecutive number of days greater than or equal to 12.5% of the growing season are wedands, provided the soil and vegetation parameters are met. Areas inundated or saturated between 5 and 12.5% of the growing season in most years may or may not be wedands. Areas saturated to the surface for less than 5% of the growin� season are non- we[lands." Field indicators are used for determining whether wetland hydrology parameters,are met. 4 ��