THE DIRTBID REGIONAL MODEL · WASHINGTON
Sitework in Washington on the same Richmond Metro = 1.00 scale as the rest of DirtBid: 14 cost regions and 39 counties, each with a soil-risk rating from USDA and USGS data. Seattle Metro runs highest at 1.14×; Lewiston Metro (Washington side) lowest at 0.87×.
Washington 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: Alderwood, Playco, Pitcher
3 counties in this region. Highest risk score: Pierce County (5 of 10). This multiplier sits outside the range the model was tested on, so treat it as rougher.
Counties: King County, Pierce County, Snohomish County
Dominant ground: Athena, Hoquiam, Walla Walla
20 counties in this region. 9 of 20 rate high for shallow rock. 3 of 20 rate high for water table. Deep frost protection is likely in 3 of 20. Highest risk score: Lewis County (6 of 10).
Counties: Adams County, Clallam County, Columbia County, Ferry County, Garfield County, Grant County, Grays Harbor County, Island County, Jefferson County, Kittitas County, Klickitat County, Lewis County, Lincoln County, Mason County, Okanogan County, Pacific County, Pend Oreille County, San Juan County, Wahkiakum County, Whitman County
Dominant ground: Naff, Rockly, Cheney
2 counties in this region. 1 of 2 rate high for shallow rock. Highest risk score: Spokane County (4 of 10).
Counties: Spokane County, Stevens County
Dominant ground: Cinebar, Olympic, Hesson
2 counties in this region. Highest risk score: Clark County (4 of 10).
Counties: Clark County, Skamania County
Dominant ground: Ritzville, Warden, Xeric Haplocambids
2 counties in this region. Highest risk score: Franklin County (4 of 10).
Counties: Benton County, Franklin County
Dominant ground: Spanaway, Everett, Alderwood
1 county in this region. Highest risk score: Thurston County (4 of 10).
Counties: Thurston County
Dominant ground: Alderwood, Harstine, Shelton
1 county in this region. 1 of 1 rate high for water table. 1 of 1 rate high for dewatering. Highest risk score: Kitsap County (5 of 10).
Counties: Kitsap County
Dominant ground: Warden, Ritzville, Typic Vitricryands
1 county in this region. Highest risk score: Yakima County (4 of 10).
Counties: Yakima County
Dominant ground: Doubtful, Typic Vitricryands, Whatcom
1 county in this region. 1 of 1 rate high for shallow rock. Deep frost protection is likely in 1 of 1. Highest risk score: Whatcom County (5 of 10).
Counties: Whatcom County
Dominant ground: Vanzandt, Kindy, Montborne
1 county in this region. Highest risk score: Skagit County (4 of 10).
Counties: Skagit County
Dominant ground: Entiat, Andic Cryumbrepts, Nard
2 counties in this region. 2 of 2 rate high for shallow rock. Highest risk score: Chelan County (4 of 10).
Counties: Chelan County, Douglas County
Dominant ground: Hazeldell, Olympic, Vanson
1 county in this region. Highest risk score: Cowlitz County (4 of 10).
Counties: Cowlitz County
Dominant ground: Ritzville, Walla Walla, Quincy
1 county in this region. Highest risk score: Walla Walla County (4 of 10).
Counties: Walla Walla County
Dominant ground: Limberjim, Anatone, Larabee
1 county in this region. 1 of 1 rate high for shallow rock. Highest risk score: Asotin County (4 of 10).
Counties: Asotin County
FAQ
From USDA soil survey data, the most common across the state: shallow rock (14 of 39 counties rate high), water table (4 of 39 counties rate high), dewatering (4 of 39 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 Washington, 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.