Sinkhole risk in Sussex County, DE: No soluble rock mapped

What to do about a house in Sussex County

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

Across 936 square miles, under one square mile of Sussex County maps onto soluble rock. With about 271,134 residents (290 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 310 map points about 1.7 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 Sussex County

The nearest county rated sinkhole country is Jefferson County, WV, about 143 miles west. 5 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

• Wicomico County, MD 26 mi southwest · 0% at surface
• Caroline County, MD 30 mi northwest · 10% at surface
• Kent County, DE 31 mi north · 0% at surface
• Worcester County, MD 31 mi south · 0% at surface
• Cape May County, NJ 39 mi northeast · 0% at surface
• Dorchester County, MD 42 mi southwest · 0% at surface

Against the rest of Delaware

Sussex County ranks 3 of 3 in Delaware for soluble rock at the surface, and sits above 0% of US counties on that measure.

• New Castle County under 1%
• Kent County 0%