Butte County, CA Shrink-Swell Risk
Butte County, CA's soil, for shrink-swell risk
Moderate
Butte County, CA: USDA's soil survey rates 67.6% of the county "Moderate" for shrink-swell potential (3.05% linear extensibility). That's a middle reading: not the sharp swings that crack a foundation outright, but enough that grading and drainage are worth getting right.
What Butte County's reading doesn't cover
Two lots a mile apart in Butte County can carry different soil, even though they share one countywide reading. The real answer for one lot is still a site-specific geotechnical report, running about $1,000-$5,000 (typically near $2,700).
What it costs to find out, versus to ignore it
With Butte County, CA rating "Moderate", a geotechnical report is still worthwhile before a build, just less urgent than in a high-risk county. A geotechnical report runs $1,000-$5,000, typically around $2,700. Foundation repair, if a specific lot turns out to differ from the county average, runs $5,000-$15,000.
Where this sits nationally
Nationally, Butte County, CA is the 1,155-most-constrained of 3,085 rated counties for shrink-swell soil. Within California alone it ranks 25 of 58. Butte County, CA is 1,637 square miles with a population of 208,334.
See how another county compares
Orleans Parish, LA carries this site's most-constrained reading. Pierce County, WI and McKinley County, NM are worth a look for comparison.
How this reading is built, and its real limits · Moisture management: the cheap fix that works on any soil
More of California
Every county in California is on this site, including Imperial County, CA and Trinity County, CA. The full underlying dataset is downloadable directly, one row per county.