Sullivan County Lake Quality
New York, 4 lakes, average grade C (Fair)
Sullivan County has 4 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. Sullivan County averages to a C. The distribution behind that average matters more than the letter: a few stressed lakes versus many decent ones can produce the same average as the inverse.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Anawanda Lake (A) is the cleanest in the county.
Quick Answers for Sullivan County
Planning a trip? Check special fishing regulations for Anawanda Lake — or check the official New York fishing regulations.
All Lakes in Sullivan County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Anawanda Lake | A | 18.4 ft | - |
| 2 | Montgomery Lake | B | 13.9 ft | - |
| 3 | Pleasure Lake | D | 4.3 ft | - |
| 4 | Swamp Pond | D | 3.9 ft | - |
Other Counties in New York
See how Sullivan County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 15 states.
Where to stay near Sullivan County
Top-rated places to stay near Sullivan County
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Source: EPA National Aquatic Resource Surveys, 2026.