Laserfiche WebLink
SITE HYDRAULIC ANALYSIS <br />Per NRCS survey of Snohomish County, the project site contains Alderwood soils that <br />have a hydrologic classification of Type "C". <br />EXISTING BASIN SUMMARY <br />Total Clearing Area = 0.39 Acres <br />Frontage Area H = 0.04 Acres <br />Existing Basin Area = 0.43 Acres <br />Impervious Areas: <br />Roof = 954 SF (0.02 Acres) <br />Walkway = 267 SF (0.01 Acres) <br />Driveway = 1,938 SF (0.04 Acres) <br />Total Impervious = 3,159 SF (0.07 Acres) <br />Total Pervious Areas = 0.43 Acres — 0.07 Acres = 0.36 Acres <br />Refer to the Existing Basin Map for basin representation. <br />DEVELOPED BASIN SUMMARY <br />Total Clearing Area = 0.39 Acres <br />Frontage Area H = 0.04 Acres <br />Total Area Included in the Analysis = 0.43 Acres <br />Impervious Areas: <br />Roof = 2,173 SF (0.05 Acres) <br />Existing Roof = 954 SF (0.02 Acres) <br />Driveway (Permeable) = 2,175 SF (0.05 Acres) <br />Frontage Sidewalk = 407 SF (0.01 Acres) <br />Asphalt = 289 SF (0.00 Acres) <br />Total Impervious = 5,998 SF (0.13 Acres) <br />Total Pervious Areas = 0.43 Acres - 0.13 Acres = 0.30 Acres <br />Total New Effective Impervious Surface = 3,823 SF <br />Refer to the Developed Basin Map for basin representation. <br />Insight Engineering Co. — Stormwater Site Plan 05/31/2022 <br />-29- <br />