Sinkhole risk in Lynchburg city, VA: No soluble rock mapped

What to do about a house in Lynchburg city

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

Across 49 square miles, under one square mile of Lynchburg city maps onto soluble rock. With about 80,301 residents (1,642 per square mile), most of the county is built up, so a mapped unit is likely to sit under somebody's street. The figures come from 575 map points about 0.3 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: how these percentages are measured, and the warning signs that apply anywhere.

Counties around Lynchburg city

The nearest county rated sinkhole country is Buena Vista city, VA, about 25 miles north, close enough that the same rock may run under the county line. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.

• Campbell County, VA 14 mi southeast · 2% at surface
• Amherst County, VA 16 mi north · under 1% at surface
• Bedford County, VA 19 mi west · 4% at surface
• Appomattox County, VA 21 mi east · 2% at surface
• Buena Vista city, VA 25 mi north · 75% at surface
• Lexington city, VA 30 mi northwest · 100% at surface

Which formation it is

The largest mapped soluble unit here is the Alligator Back Formation - Banded marble (marble), Proterozoic Z-Cambrian in age, covering about under 1% of the county.

Against the rest of Virginia

Lynchburg city ranks 89 of 133 in Virginia for soluble rock at the surface, and sits above 53% of US counties on that measure.

• Lexington city 100%
• Salem city 100%
• Roanoke city 98%
• Winchester city 90%
• Bristol city 89%