New York lakes: toxic algae status
Harmful algal bloom (blue-green algae) reports for New York lakes and rivers, from the New York State Department of Environmental Conservation (DEC).
Data published as a yearly summary; the current season is shown on the NYHABS map. Latest entry: 19 November 2025. For today's conditions, see the NYHABS map.
566
waterbodies with a bloom report (2012–2025)
352
lakes with enough history for a full page
247
lakes with blooms in 3 or more different years
Lakes with the most bloom years
| Lake | County | Years with blooms |
|---|---|---|
| Rockland Lake | Rockland | 14 |
| Chautauqua Lake | Chautauqua | 14 |
| Honeoye Lake | Ontario | 14 |
| Orange Lake | Orange | 14 |
| Black Lake | St. Lawrence | 13 |
| Agawam Lake | Suffolk | 13 |
| Maratooka Lake | Suffolk | 13 |
| Mill Pond | Suffolk | 13 |
| Prospect Park Lake | Kings | 13 |
| Song Lake | Cortland | 13 |
| Oneida Lake | Oswego | 12 |
| Findley Lake | Chautauqua | 12 |
| Harlem Meer | New York | 12 |
| Java Lake | Wyoming | 12 |
| Kissena Lake | Queens | 12 |
Browse by county
- Albany County (11 waterbodies)
- Allegany County (5 waterbodies)
- Bronx County (2 waterbodies)
- Broome County (14 waterbodies)
- Cattaraugus County (8 waterbodies)
- Cayuga County (8 waterbodies)
- Chautauqua County (7 waterbodies)
- Chemung County (2 waterbodies)
- Chenango County (13 waterbodies)
- Clinton County (3 waterbodies)
- Columbia County (11 waterbodies)
- Cortland County (9 waterbodies)
- Delaware County (7 waterbodies)
- Dutchess County (21 waterbodies)
- Erie County (7 waterbodies)
- Essex County (10 waterbodies)
- Franklin County (18 waterbodies)
- Fulton County (3 waterbodies)
- Genesee County (1 waterbody)
- Greene County (5 waterbodies)
- Hamilton County (12 waterbodies)
- Herkimer County (4 waterbodies)
- Jefferson County (15 waterbodies)
- Kings County (1 waterbody)
- Livingston County (4 waterbodies)
- Madison County (10 waterbodies)
- Monroe County (8 waterbodies)
- New York County (4 waterbodies)
- Niagara County (6 waterbodies)
- Oneida County (3 waterbodies)
- Onondaga County (10 waterbodies)
- Ontario County (7 waterbodies)
- Orange County (22 waterbodies)
- Oswego County (11 waterbodies)
- Otsego County (11 waterbodies)
- Putnam County (32 waterbodies)
- Queens County (7 waterbodies)
- Rensselaer County (13 waterbodies)
- Richmond County (10 waterbodies)
- Rockland County (11 waterbodies)
- Saratoga County (7 waterbodies)
- Schenectady County (3 waterbodies)
- Schoharie County (9 waterbodies)
- Schuyler County (7 waterbodies)
- Seneca County (3 waterbodies)
- St. Lawrence County (8 waterbodies)
- Steuben County (7 waterbodies)
- Suffolk County (55 waterbodies)
- Sullivan County (24 waterbodies)
- Tompkins County (4 waterbodies)
- Ulster County (13 waterbodies)
- Warren County (10 waterbodies)
- Washington County (6 waterbodies)
- Wayne County (5 waterbodies)
- Westchester County (31 waterbodies)
- Wyoming County (4 waterbodies)
- Yates County (2 waterbodies)
Source: New York State Department of Environmental Conservation (DEC), official data. This site is independent and not affiliated with the State of New York.