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Amador Soil Series

USDA Code: CA0013

K-Factor

0.2

Soil Erodibility Factor

Texture Class

sandy loam

Drainage Class

well drained

About Amador

Shallow, well drained soils formed in material weathered from rhyolite and other acidic volcanic rocks. Typically less than 20 inches to weathered bedrock (paralithic contact). Found on rolling to steep foothills at 300–2,000 ft elevation.

K factor values are sourced from the USDA Natural Resources Conservation Service (NRCS) SSURGO database.

Using Amador in a RUSLE calculation

For a California construction project, use the soil K factor with rainfall erosivity, slope length and steepness, cover management, and support practice inputs. The K factor represents the soil erodibility portion of the model, so selecting the soil series that matches the site is important for defensible stormwater documentation.

In a SWPPP workflow, the practical question is not just what soil type is mapped near the project. It is whether the mapped series, K factor, and drainage assumptions match the site evidence well enough to support the RUSLE or RUSLE2 calculation.

California Distribution

Characteristic of the gold-bearing rhyolite country of Amador, Calaveras, and Tuolumne counties. Shallow depth limits agricultural use; much is in rangeland or scrub.

Counties Where Found

Amador soil FAQ

What is the K factor for Amador soil?

Amador has a listed K factor of 0.2 in the Rapid RUSLE soil directory. Confirm final values against project specific soil survey data before submitting permit documents.

Where is Amador soil found in California?

Amador is mapped in Amador, Calaveras, El Dorado, and other California counties. County mapping is based on available soil series data and should be verified for the exact project location.

How is Amador used in RUSLE erosion calculations?

Use the Amador K factor as the soil erodibility input in RUSLE or RUSLE2, along with rainfall, slope, cover, and support practice factors for the site.

Calculate erosion risk with Amador soil data

Start a Rapid RUSLE project with this soil's K-factor (0.2) pre-loaded. Get accurate RUSLE erosion risk assessments in minutes.

Start a Rapid RUSLE project with this soil

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