Sinkhole risk in Lewis County, NY: 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
- 9%
- At or near the surface
- 0%
- Buried under cover
- 9%
What to do about a house in Lewis County
Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.
That works out to roughly 120 of Lewis County's 1,276 square miles on soluble rock. With about 26,570 residents (21 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 256 map points about 2.2 miles apart, so a pocket smaller than that can be missed or overstated.
Read next: why the 9% under cover still counts, and how these percentages are measured.
Counties around Lewis County
The nearest county rated sinkhole country is Union County, PA, about 212 miles southwest. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.
- Herkimer County, NY 33 mi southeast · 0% at surface
- Jefferson County, NY 34 mi northwest · 0% at surface
- Oneida County, NY 37 mi south · 0% at surface
- Oswego County, NY 44 mi southwest · 0% at surface
- Hamilton County, NY 48 mi east · 0% at surface
- St. Lawrence County, NY 52 mi north · under 1% at surface
What Lewis County is built on
The largest mapped soluble unit here is the Trenton Group (shale), Middle Ordovician in age, covering about 7% of the county. Next is the Black River Group at under 1%.
Against the rest of New York
Lewis County ranks 28 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.
- New York County under 1%
- St. Lawrence County under 1%
- Saratoga County under 1%
- Cayuga County under 1%
- Clinton County under 1%