The Spokane County Soil Survey

“ A nation that destroys its soil, destroys itself.” Franklin Roosevelt

Soil, the living skin of the earth, impacts everything we do in our world. It is among the most basic and valuable of all the natural resources found in the world. Soil produces the food that we eat, provides a foundation for our structures, supports life to all earthly ecosystems and filters our wastes. Since the devastating days of the Dust Bowl in the 1930’s, the Soil Conservation Act of 1935 made the care of soil a priority of Conservation Districts.

The first step in taking proper care of the soil is to promote an understanding and awareness of its importance, uniqueness and fragility. To accomplish this there needs to be a basic inventory of the different soils and how they exist in relation to climate and plants. Consequently each county performs a Soil Survey to inventory the more than 23,000 soil series that occur in various combinations with different slopes and surface textures in the U.S.

The Spokane County Soil Survey (c. 1968) is out of date, no longer in print and the published base imagery flown in 1950 no longer depicts current land use. The Surveys’ main interpretive focus was for agricultural purposes. Some map unit delineations and major soil components like the Hesseltine soil series and associated map units had too broad of an interpretive range and covered a large geographical area.County zoning codes and ordinances have language based on specific soil survey information such as percent slope and land capability class.

• The purpose of the update is to provide current and accurate soil information and interpretations for various land uses within Spokane County and the City of Spokane.
• Soil mapping and data collection were conducted using a mix of traditional methods and new technologies.
• Soil scientists equipped with hand-held computers integrated with GPS and GIS applications ran transects and traverses and collected point information.
• ArcGIS was used for spatial analyses, map unit design and for quality control.
• New soil series were developed and new map units were designed to address the broadly mapped areas.
• Results show that 12 of the original 50 series were dropped, equivalent to 357,610 acres or 32% of the total survey area (1,139,504 acres). Currently the update legend has 108 series and 273 map units compared to the 1968 legend with 50 series and 179 map units. Users will benefit from improved soil maps, reports and interpretations available in an electronic format and with web access.

The Web Soil Survey can be accessed here.

We welcome input from users regarding specific needs. Please send all comments and questions to scott.bare@wa.usda.gov, Soil Survey MLRA Project Leader.

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