Porterville Soil Series
USDA Code: CA0573
K-Factor
0.37
Soil Erodibility Factor
Texture Class
clay
Drainage Class
moderately well drained
About Porterville
Deep, moderately well drained soils formed in alluvium derived from mixed sedimentary and metamorphic rocks. High smectite clay content (>40%) with strong vertic properties. Found on alluvial fans and plains at the foot of the Sierra Nevada and Tehachapi Mountains.
K factor values are sourced from the USDA Natural Resources Conservation Service (NRCS) SSURGO database.
Using Porterville 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
Mapped extensively in Tulare, Kern, and Kings counties. Named for the city of Porterville. Heavy clay causes severe shrink-swell; challenging for construction but valuable for agriculture where drainage is managed.
Counties Where Found
Porterville soil FAQ
What is the K factor for Porterville soil?
Porterville has a listed K factor of 0.37 in the Rapid RUSLE soil directory. Confirm final values against project specific soil survey data before submitting permit documents.
Where is Porterville soil found in California?
Porterville is mapped in Kern, Kings, Tulare. County mapping is based on available soil series data and should be verified for the exact project location.
How is Porterville used in RUSLE erosion calculations?
Use the Porterville 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 Porterville soil data
Start a Rapid RUSLE project with this soil's K-factor (0.37) pre-loaded. Get accurate RUSLE erosion risk assessments in minutes.
Start a Rapid RUSLE project with this soilNo login required to preview results.