Late afternoon sun over Slim Lake, scattering a bright path across wind-textured water

Lewis County Lake Quality

New York, 33 lakes, measured by NY DEC

The county-level average smooths over real differences — a single agricultural watershed near the southwest corner can pull the average down even if the rest of the county runs clean. 1 of those lake carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. The county-wide picture is low-to-moderate phosphorus with clear summer transparency across most monitored lakes.

The county's lakes lean shallow, which makes the readings sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest measured lake is Barnes Lake.

Loading map…

Where to stay near Lewis County

Top-rated places to stay near Lewis County

Prices for Oct 23–25, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a trip to Lewis County?

Get lake water-quality updates plus the best cabin & lodging deals near Lewis County — straight to your inbox. No spam, unsubscribe anytime.

Quick Answers for Lewis County

Cleanest lakes in Lewis County →Cleanest lakes in New York →Best swimming lakes in New York →

Planning a trip? Check special fishing regulations for Barnes Lake — or check the official New York fishing regulations.

All Lakes in Lewis County

33 lakes · 1 ranked on readings, 32 without enough sampling1 lake ranked on readings · 32 without enough sampling, hidden

Include not-rated lakes (32)

#	Lake	Clarity	Phosphorus	Algae	Trophic	Max Depth	Access
1	Barnes LakeLewis	No recent samples	13 µg/L	8.4 µg/L	No recent samples	No recent samples	Not recorded
	Lake BonaparteLewis	15.8 ft	No recent samples	No recent samples	No recent samples	No recent samples	✓ Public
	Brantingham LakeLewis	10.7 ft	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Copper LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	22.6 ft	Not recorded
	Pine LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	13.1 ft	Not recorded
	Francis LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	23 ft	Not recorded
	Crystal LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	45.9 ft	Not recorded
	Huckleberry LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	26.2 ft	Not recorded
	Stony LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	19.7 ft	Not recorded
	Fish PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Chase LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	59.1 ft	Not recorded
	Little Otter LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	26.2 ft	Not recorded
	Catspaw LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Sears PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	South Greek LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	16.1 ft	Not recorded
	Elijah LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	33.1 ft	Not recorded
	Bullhead PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Indian PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Crooked PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Narrow LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Ashcraft PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Mud PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Soft Maple ReservoirLewis	No recent samples	No recent samples	No recent samples	No recent samples	57.7 ft	Not recorded
	Effley Falls PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	21.3 ft	Not recorded
	Taylorville PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	26.2 ft	Not recorded
	Belfort PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	16.4 ft	Not recorded
	High Falls PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	40 ft	Not recorded
	Beaver LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	29.5 ft	Not recorded
	Crooked LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	No recent samples	Not recorded
	Sand PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	19.7 ft	Not recorded
	Round PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	26.2 ft	Not recorded
	Long PondLewis	No recent samples	No recent samples	No recent samples	No recent samples	59.1 ft	Not recorded
	Trout LakeLewis	No recent samples	No recent samples	No recent samples	No recent samples	39.4 ft	Not recorded

NR = no nutrient or algae reading on record. The measurements are published as the authority reports them. Where the data comes from.

Lake Match

Which lake suits how you actually use one?

Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of lakes that fit, with the water quality behind each one.

Take the quiz →

Other Counties in New York

4 lakes

198 lakes

110 lakes

129 lakes

134 lakes

18 lakes

Browse every New York lake, or the full directory of lakes across all United States (49 states), Canada (Ontario, Québec, Nova Scotia, British Columbia and Newfoundland and Labrador), and 38 other country hubs..

Source: the New York Department of Environmental Conservation. See data sources.