Sinkhole risk in District of Columbia, DC: Mostly deep or small
Mostly deep or small
Some soluble rock, mostly deeply buried or in a small share of the county.
- On soluble rock
- 1%
- At or near the surface
- 1%
- Buried under cover
- 0%
What this means before you buy
Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.
Across 61 square miles, under one square mile of District of Columbia maps onto soluble rock. With about 702,250 residents (11,488 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 449 map points about 0.4 miles apart, so a pocket smaller than that can be missed or overstated.
Read next: how these percentages are measured, and the warning signs that apply anywhere.
Counties around District of Columbia
The nearest county rated sinkhole country is Jefferson County, WV, about 53 miles northwest. 1 of the 6 closest counties land in the same band; the ground changes quickly around here.
- Arlington County, VA 5 mi west · 0% at surface
- Alexandria city, VA 7 mi southwest · 0% at surface
- Falls Church city, VA 9 mi west · 0% at surface
- Prince George's County, MD 10 mi southeast · 22% at surface
- Fairfax County, VA 15 mi west · 2% at surface
- Fairfax city, VA 16 mi west · 0% at surface
What District of Columbia is built on
The largest mapped soluble unit here is the Chesapeake Group; Calvert Formation (sand), Miocene in age, covering about 1% of the county.