THE DIRTBID REGIONAL MODEL · CALIFORNIA
Sitework in California on the same Richmond Metro = 1.00 scale as the rest of DirtBid: 26 cost regions and 58 counties, each with a soil-risk rating from USDA and USGS data. San Francisco Metro runs highest at 1.20×; El Centro Metro lowest at 0.93×.
California multipliers and county ratings are planning-level: built from federal price and soil data, and not yet checked against local bids or a local estimator.
Dominant ground: Millsholm family, Trigo family, Hesperia
2 counties in this region. 2 of 2 rate high for shallow rock. Highest risk score: Los Angeles County (4 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Los Angeles County, Orange County
Dominant ground: Cieneba, Lithic Xerorthents, Pintobasin
2 counties in this region. 1 of 2 rate high for shallow rock. Highest risk score: Riverside County (4 of 10).
Counties: Riverside County, San Bernardino County
Dominant ground: Los Osos, Orthents, Vallecitos
5 counties in this region. 1 of 5 rate high for shrink-swell clay. 1 of 5 rate high for shallow rock. Highest risk score: San Francisco County (5 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Alameda County, Contra Costa County, Marin County, San Francisco County, San Mateo County
Dominant ground: Fallbrook, Cieneba, La Posta
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: San Diego County (4 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: San Diego County
Dominant ground: Waca, Mariposa, Auburn
4 counties in this region. 2 of 4 rate high for shallow rock. 1 of 4 rate high for shrink-swell clay. Highest risk score: Sacramento County (5 of 10).
Counties: El Dorado County, Placer County, Sacramento County, Yolo County
Dominant ground: Vallecitos, San Benito, Diablo
2 counties in this region. 2 of 2 rate high for shallow rock. Highest risk score: San Benito County (5 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: San Benito County, Santa Clara County
Dominant ground: Holland family, Typic Cryorthents, Hesperia
2 counties in this region. 1 of 2 rate high for shallow rock. Highest risk score: Fresno County (4 of 10).
Counties: Fresno County, Madera County
Dominant ground: Cajon, Kimberlina, Millsholm family
1 county in this region. Highest risk score: Kern County (4 of 10).
Counties: Kern County
Dominant ground: Gerle family, Loafercreek, Millsholm
21 counties in this region. 18 of 21 rate high for shallow rock. 1 of 21 rate high for shrink-swell clay. Highest risk score: Alpine County (5 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Alpine County, Amador County, Calaveras County, Colusa County, Del Norte County, Glenn County, Humboldt County, Inyo County, Lake County, Lassen County, Mariposa County, Mendocino County, Modoc County, Mono County, Nevada County, Plumas County, Sierra County, Siskiyou County, Tehama County, Trinity County, Tuolumne County
Dominant ground: Millsholm family, Hesperia, Hanford
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Ventura County (4 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Ventura County
Dominant ground: Capay, Rindge, Tokay
1 county in this region. Highest risk score: San Joaquin County (4 of 10).
Counties: San Joaquin County
Dominant ground: Pentz, Dinuba, Wisflat
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Stanislaus County (4 of 10).
Counties: Stanislaus County
Dominant ground: Hugo, Laughlin, Josephine
1 county in this region. Highest risk score: Sonoma County (4 of 10).
Counties: Sonoma County
Dominant ground: Cieneba, Auberry, Typic Cryorthents
1 county in this region. Highest risk score: Tulare County (4 of 10).
Counties: Tulare County
Dominant ground: Capay, Yolo, San Ysidro
1 county in this region. 1 of 1 rate high for shrink-swell clay. Highest risk score: Solano County (4 of 10).
Counties: Solano County
Dominant ground: Millsholm family, Millerton family, Agua Dulce family
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Santa Barbara County (4 of 10).
Counties: Santa Barbara County
Dominant ground: Cieneba, Santa Lucia, Shedd
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Monterey County (4 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Monterey County
Dominant ground: Delhi, Atwater, Fresno
1 county in this region. 1 of 1 rate high for water table. 1 of 1 rate high for dewatering. Highest risk score: Merced County (5 of 10).
Counties: Merced County
Dominant ground: Millsholm family, Millerton family, Nacimiento
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: San Luis Obispo County (4 of 10).
Counties: San Luis Obispo County
Dominant ground: Ben Lomond, Felton, Lompico
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Santa Cruz County (4 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Santa Cruz County
Dominant ground: Esquon, Sheld, Xerorthents
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Butte County (5 of 10).
Counties: Butte County
Dominant ground: Clear Lake, Capay, Oswald
2 counties in this region. 1 of 2 rate high for shrink-swell clay. 1 of 2 rate high for shallow rock. Highest risk score: Sutter County (5 of 10).
Counties: Sutter County, Yuba County
Dominant ground: Imperial, Indio, Rositas
1 county in this region. Highest risk score: Imperial County (4 of 10).
Counties: Imperial County
Dominant ground: Cohasset, Newtown, Toomes
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Shasta County (4 of 10).
Counties: Shasta County
Dominant ground: Tulare, Nord, Kimberlina
1 county in this region. 1 of 1 rate high for water table. 1 of 1 rate high for dewatering. Highest risk score: Kings County (5 of 10).
Counties: Kings County
Dominant ground: Bressa, Henneke, Forward
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Napa County (4 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: Napa County
FAQ
From USDA soil survey data, the most common across the state: shallow rock (38 of 58 counties rate high), shrink-swell clay (5 of 58 counties rate high), water table (3 of 58 counties rate high). A parcel can differ from its county, so read the survey for your exact site.
From the Commerce Department's Regional Price Parities, on the same Richmond Metro = 1.00 scale as Virginia. Across 29 reviewed regions that method missed by about 0.03 on average. They have not been checked against executed bids in California, so use them for planning, not a final bid.
They are screening ratings from federal soil and geology data, not a local estimator's review and not a geotechnical report. Tested against 511 reviewed counties, they land within one level most of the time, and exact matches are less common. Get borings before you price a real site.
Soil Report
A $350 DirtBid AI Soil Report reads the official USDA survey for your exact parcel, flags the hazards above, and prices the risk — before you buy land or sign a contract.