600 54TH ST SW I 2025-01-28 - Laserfiche WebLink

Map Unit Composition • Alderwood and similar soils: 60 percent • Urban land: 25 percent • Minor components: 5 percent • Estimates are based on observations, descriptions, and transects of the mapunit. Description of Alderwood Setting • Landform: Till plains • Parent material: Basal till Typical profile • HI - 0 to 7 inches: gravelly ashy sandy loam • H2 - 7 to 35 inches: very gravelly ashy sandy loam • H3 - 35 to 60 inches: gravelly sandy loam Properties and qualities • Slope: 8 to 15 percent • Depth to restrictive feature: 20 to 40 inches to densic material • Natural drainage class: Moderately well drained • Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately low (0.00 to 0.06 in/hr) • Depth to water table: About 18 to 36 inches • Frequency of flooding: None • Frequency of ponding: None • Available water storage in profile: Low (about 3.0 inches) Interpretive groups • Land capability classification (irrigated): None specified • Land capability classification (nonirrigated): 4s • Hydrologic Soil Group: B • Forage suitability group: Limited Depth Soils (G002XN302WA) • Hydric soil rating: No Minor Components Norma, undrained • Percent of map unit: 5 percent • Landform: Drainageways • Hydric soil rating: Yes Snohomish County Area, Washington 19—Everett very gravelly sandy loam, 15 to 30 percent slopes Map Unit Setting • National map unit symbol: 2t62c • Elevation: 30 to 900 feet • Mean annual precipitation: 35 to 91 inches Insight Engineering Co. -Stormwater Site Plan 07/03/2019 - 11 -