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

Snohomish County Area, Washington 3—Alderwood gravelly sandy loam, 15 to 30 percent slopes Map Unit Setting • National map unit symbol: 2t627 • Elevation: 0 to 1,000 feet • Mean annual precipitation: 25 to 60 inches • Mean annual air temperature: 46 to 52 degrees F • Frost-free period: 160 to 240 days • Farmland classification: Farmland of statewide importance Map Unit Composition • Alderwood and similar soils: 85 percent • Minor components: 15 percent • Estimates are based on observations, descriptions, and transects of the mapunit. Description of Alderwood Setting • Landform: Ridges, hills • Landform position (two-dimensional): Backslope • Landform position (three-dimensional): Side slope, nose slope, talf • Down-slope shape: Linear, convex • Across-slope shape: Convex • Parent material: Glacial drift and/or glacial outwash over dense glaciomarine deposits Typical profile • A - 0 to 7 inches: gravelly sandy loam • Bw1 - 7 to 21 inches: very gravelly sandy loam • Bw2 - 21 to 30 inches: very gravelly sandy loam • Bg - 30 to 35 inches: very gravelly sandy loam • 2Cd1 - 35 to 43 inches: very gravelly sandy loam • 2Cd2 - 43 to 59 inches: very gravelly sandy loam Properties and qualities • Slope: 15 to 30 percent • Depth to restrictive feature: 20 to 39 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 37 inches • Frequency of flooding: None • Frequency of ponding: None • Available water storage in profile: Very low (about 2.7 inches) Interpretive groups • Land capability classification (irrigated): None specified • Land capability classification (nonirrigated): 4e • Hydrologic Soil Group: B Insight Engineering Co. -Stormwater Site Plan 07/03/2019 -9-