Richland County, SC Shrink-Swell Risk
Shrink-swell potential in Richland County, SC
Low
Soil across 96.7% of Richland County, SC comes back "Low" in USDA's shrink-swell data, averaging 1.63% linear extensibility. Among the 3,144 counties on this site, that's the clean result: little shrink-swell movement, standard construction the likely outcome.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Richland County, SC - never a reading for one specific parcel. A local geotechnical report, typically $1,000-$5,000 (around $2,700 typical), is the only way to know what one lot in Richland County will actually do.
Richland County: the real numbers
Richland County's soil reading points toward standard foundation practice as the likely outcome, not the exception. 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
Among the 3,085 rated counties on this site, Richland County, SC ranks 2,348 most-constrained nationally, and 30 of 46 within South Carolina. Richland County covers 757 square miles and counts 430,651 residents.
See how another county compares
Orleans Parish, LA carries this site's most-constrained reading. Norman County, MN and Chester County, PA 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
Elsewhere in South Carolina
Every county in South Carolina is on this site, including Florence County, SC and Lancaster County, SC. The full underlying dataset is downloadable directly, one row per county.