Updated Aug 2026
New York Lake Water Quality
Water quality grades for 189 monitored lakes across 48 counties.
Across New York, 189 lakes carry an active water-quality grade spread over 48 counties. The underlying measurements come from the New York Department of Environmental Conservation, alongside federal programs and volunteer monitoring networks. Only about 6% of New York's lakes pull an A grade — the smaller, agricultural-watershed lakes that dominate the dataset tend to carry persistent nutrient loads. 2% of lakes fall in the D or F brackets.
Most New York lakes sit in the mesotrophic band — moderate productivity, decent clarity, capable of supporting both warm-water and cool-water fisheries. This is the band where well-managed working lakes tend to land. Cayuga ranks highest on average county grade (A). Monroe sits lowest. With only 48 counties in the state, the cross-county spread is narrower than the within-county spread for most lakes.
Grade Distribution
All 189 New York lakes in the index: 27 (14.3%) carry an A–F grade and 162 (85.7%) are not rated, because they lack enough recent nutrient or algae sampling to support a letter.
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Top-Graded New York Lakes
The highest water-quality grades in New York — clarity, depth, and A-F grade at a glance.
Lake Map
Explore New York Lakes
New York reports, fishing & travel
New York's cleanest and most-polluted lakes, ranked A–F
Species activity outlook by water temperature and season
Where to stay at New York's top lakes, each with its grade
Best-graded lakes within 50 miles of Syracuse
Best-graded lakes within 50 miles of Rochester
Best-graded lakes within 50 miles of Albany
Reservoirs in New York
View all 60 reservoirs →60 of 189 New York lakes (32%) are man-made reservoirs in the USACE National Inventory of Dams. 36 carry a High or Significant hazard rating. The oldest matched dam dates to 1820.
EPA-Impaired Lakes in New York
View all 99 impaired lakes →99 of 189 New York lakes (52%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 35 have an approved Total Maximum Daily Load (TMDL) restoration plan.
New York Fishing & Recreation
Licenses, regulations, records, and where to fish across New York.
Counties
All 48 New York counties, ranked by average lake water quality. Compare them against every county nationwide in the county rankings, browse the full directory of graded lakes, or pick a different state.
New York Lake Water Quality Dataset (2026)
Every graded New York lake in one spreadsheet — A–F grade, water clarity, phosphorus, chlorophyll-a, trophic state, size, public access, and a link to each lake's report card.
Top 25 Cleanest Lakes
25 lakes25 graded lakes
| # | Lake | County | Grade | Clarity | Trophic | Access |
|---|---|---|---|---|---|---|
| 1 | AOwasco Lake Platform | Cayuga | A | 11 ft | Oligotrophic | Not recorded |
| 2 | ASeneca Lake Platform | Seneca | A | 11.5 ft | Mesotrophic | ✓ Public |
| 3 | AQueneska Island Lake | Essex | A | 17.4 ft | Mesotrophic | Not recorded |
| 4 | ASouth Lake | Herkimer | A | No recent samples | Oligotrophic | Not recorded |
| 5 | AWest Pond | Herkimer | A | No recent samples | Mesotrophic | Not recorded |
| 6 | ASquash Pond | Herkimer | A | No recent samples | Oligotrophic | ✓ Public |
| 7 | AWillys Lake | Herkimer | A | No recent samples | Oligotrophic | Not recorded |
| 8 | AWindfall Pond | Herkimer | A | No recent samples | Oligotrophic | Not recorded |
| 9 | ALoon Hollows Pond | Herkimer | A | No recent samples | Oligotrophic | Not recorded |
| 10 | ACarry Pond | Hamilton | A | No recent samples | Mesotrophic | Not recorded |
| 11 | AJockeybush Lake | Hamilton | A | No recent samples | Mesotrophic | Not recorded |
| 12 | AWillis Lake | Hamilton | A | No recent samples | Oligotrophic | Not recorded |
| 13 | BSochia Pond | Franklin | B | No recent samples | Oligotrophic | ✓ Public |
| 14 | BSunday Pond | Franklin | B | No recent samples | Oligotrophic | ✓ Public |
| 15 | BBarnes Lake | Lewis | B | No recent samples | Mesotrophic | Not recorded |
| 16 | CIsle la Motte Lake | Clinton | C | 15.4 ft | Mesotrophic | ✓ Public |
| 17 | CIsle la Motte Lake | Clinton | C | 12.5 ft | Mesotrophic | ✓ Public |
| 18 | CMain Section Lake | Essex | C | 15.7 ft | Mesotrophic | Not recorded |
| 19 | CMain Section Lake | Clinton | C | 14.8 ft | Mesotrophic | ✓ Public |
| 20 | CLittle Clear Pond | Franklin | C | No recent samples | Mesotrophic | Not recorded |
| 21 | CHope Pond | Franklin | C | No recent samples | Eutrophic | Not recorded |
| 22 | CGrass Pond | Franklin | C | No recent samples | Mesotrophic | ✓ Public |
| 23 | CLittle Hope Pond | Franklin | C | No recent samples | Eutrophic | Not recorded |
| 24 | DIrondequoit Bay Lake | Monroe | D | 7.1 ft | Eutrophic | Not recorded |
| 25 | DSouthern Section Lake | Washington | D | 2 ft | Eutrophic | ✓ Public |
25 Lakes Needing Attention
25 lakes25 graded lakes
| # | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | DLittle Echo Pond | Franklin | D | No recent samples |
| 2 | DSouthern Section Lake | Essex | D | 2.6 ft |
| 3 | DSouthern Section Lake | Washington | D | 2 ft |
| 4 | DIrondequoit Bay Lake | Monroe | D | 7.1 ft |
| 5 | CLittle Hope Pond | Franklin | C | No recent samples |
| 6 | CGrass Pond | Franklin | C | No recent samples |
| 7 | CHope Pond | Franklin | C | No recent samples |
| 8 | CLittle Clear Pond | Franklin | C | No recent samples |
| 9 | CMain Section Lake | Clinton | C | 14.8 ft |
| 10 | CMain Section Lake | Essex | C | 15.7 ft |
| 11 | CIsle la Motte Lake | Clinton | C | 12.5 ft |
| 12 | CIsle la Motte Lake | Clinton | C | 15.4 ft |
| 13 | BBarnes Lake | Lewis | B | No recent samples |
| 14 | BSunday Pond | Franklin | B | No recent samples |
| 15 | BSochia Pond | Franklin | B | No recent samples |
| 16 | AWillis Lake | Hamilton | A | No recent samples |
| 17 | AJockeybush Lake | Hamilton | A | No recent samples |
| 18 | ACarry Pond | Hamilton | A | No recent samples |
| 19 | ALoon Hollows Pond | Herkimer | A | No recent samples |
| 20 | AWindfall Pond | Herkimer | A | No recent samples |
| 21 | AWillys Lake | Herkimer | A | No recent samples |
| 22 | ASquash Pond | Herkimer | A | No recent samples |
| 23 | AWest Pond | Herkimer | A | No recent samples |
| 24 | ASouth Lake | Herkimer | A | No recent samples |
| 25 | AQueneska Island Lake | Essex | A | 17.4 ft |
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.
Source: EPA National Aquatic Resource Surveys and the EPA Water Quality Portal.
More on lake water quality
The top-graded lake in every state we cover, picked grade-first with water clarity as the tie-breaker — plus the states whose winner is still not clean.
State-by-state Secchi champions: the clearest measured lake in each U.S. state we grade, which is not the same as the cleanest nutrient grade.
A data snapshot of the lakes we grade: how the A–F distribution breaks down, the clearest and the greenest states, and where the water is improving.
How lakes are graded A–F on nutrients and algae using EPA ecoregion condition classes, what each letter means in the water, and why an A is not a clearance.