Toxic algae in Sullivan County, New York
24 lakes and waterways have harmful algal bloom reports in New York's official data.
Lakes with bloom history
| Lake | Years with reports | Most recent |
|---|---|---|
| Montgomery Lake | 12 | 2023 |
| Morningside Lake | 8 | 2025 |
| Mountain Lake | 7 | 2024 |
| Pleasure Lake | 7 | 2024 |
| Evens Lake | 6 | 2025 |
| Swinging Bridge Reservoir | 6 | 2025 |
| Lake Huntington | 3 | 2017 |
| Lake Superior | 3 | 2024 |
| Loch Sheldrake | 3 | 2025 |
| Silver Lake | 3 | 2025 |
| Wolf Lake | 3 | 2022 |
| Chestnut Ridge Pond | 2 | 2025 |
| Fox Lake | 2 | 2024 |
| Mongaup Pond | 2 | 2024 |
| Toronto Reservoir | 2 | 2024 |
| Yankee Lake | 2 | 2025 |
Other waterbodies with a report
These have one or two reports in a single year, so there isn't enough history for a page of their own yet.
- Indian Field Pond (2025)
- Kiamesha Lake (2015)
- Lake Anawanda (2013)
- Lake Louise Marie (2021)
- Lochada Lake (2022)
- Swan Lake (2023)
- White Lake (2022)
- York Lake (2023)
Source: New York State Department of Environmental Conservation (DEC), official data. For current conditions see the NYHABS map.