Sinkhole risk in Colusa County, CA: No soluble rock mapped

No soluble rock mapped

No soluble bedrock mapped.

On soluble rock: 0%
At or near the surface: 0%
Buried under cover: 0%

What to do about a house in Colusa County

No soluble bedrock is mapped here, so natural sinkholes are unlikely. Collapses from broken pipes or old mines are a separate risk.

Across 1,151 square miles, under one square mile of Colusa County maps onto soluble rock. With about 22,074 residents (19 per square mile), much of the land is open, and the mapped rock may sit far from where people actually live. The figures come from 262 map points about 2.1 miles apart, so a pocket smaller than that can be missed or overstated.

Two things to read before deciding: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Colusa County

The nearest county rated sinkhole country is Emery County, UT, about 617 miles east. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

Lake County, CA 28 mi west · 2% at surface
Sutter County, CA 30 mi east · 0% at surface
Glenn County, CA 31 mi north · 0% at surface
Yolo County, CA 39 mi southeast · 0% at surface
Napa County, CA 47 mi south · 2% at surface
Butte County, CA 48 mi northeast · under 1% at surface

Against the rest of California

Colusa County ranks 30 of 58 in California for soluble rock at the surface, and sits above 0% of US counties on that measure.