Waneta Lake algae bloom history
New York's Department of Environmental Conservation listed Waneta Lake as having a harmful algal bloom in 11 of the 14 years from 2012 to 2025.
Blooms were confirmed by state staff in 6 years; in the other years they were reported as suspicious but not confirmed.
Blooms have been recorded every year for the last 6 years in the data.
That puts Waneta Lake in the top 10% of the 352 New York lakes on this site for the number of years with blooms.
- 2012 Suspicious, 6 reports
- 2013 Suspicious, 16 reports
- 2014 None
- 2015 Suspicious, 2 reports
- 2016 None
- 2017 Suspicious, 2 reports
- 2018 Suspicious, 4 reports
- 2019 None
- 2020 Confirmed, 1 report
- 2021 Confirmed, 6 reports
- 2022 Confirmed, 26 reports
- 2023 Confirmed, 18 reports
- 2024 Confirmed, 10 reports
- 2025 Confirmed, 16 reports
When do algae blooms happen at Waneta Lake?
At Waneta Lake, reports are most often logged in June, August and September.
About 100% of reports fall between May and September, when warm, calm, sunny weather lets blue-green algae multiply.
Blooms can appear, move with the wind and fade within hours or days, so the time of year is only a guide.
Recent Waneta Lake algae reports
New York publishes one entry per lake for each season it appears on the bloom list, showing when it was first and last listed and its highest status.
| Date | Result |
|---|---|
| 20 June 2025 to 23 September 2025 | Confirmed bloom |
| 11 June 2024 to 19 October 2024 | Confirmed bloom |
| 25 June 2023 to 30 September 2023 | Confirmed bloom |
| 6 August 2022 to 6 October 2022 | Confirmed bloom |
| 11 July 2021 to 13 September 2021 | Confirmed bloom |
| 7 August 2020 | Confirmed bloom |
| 14 September 2018 to 19 October 2018 | Suspicious bloom |
| 14 September 2018 to 19 October 2018 | Suspicious bloom |
| 22 September 2017 to 13 October 2017 | Suspicious bloom |
| 22 September 2017 to 13 October 2017 | Suspicious bloom |
| 25 September 2015 to 2 October 2015 | Suspicious bloom |
| 25 September 2015 to 2 October 2015 | Suspicious bloom |
What the New York results mean
New York sorts each bloom by how far it has been checked.
- Suspicious bloom
- Reported to the state but not yet confirmed as blue-green algae.
- Confirmed bloom
- State staff confirmed blue-green algae from photos or a sample. Avoid contact where the bloom is.
- High toxins
- Toxin levels high enough to be a health concern. Recorded separately from 2012 to 2018.
Is Waneta Lake safe for dogs?
Dogs are at the greatest risk from toxic algae. They swallow water while swimming, eat scum on the shore and lick algae off their fur afterwards, and a small amount can kill a dog within hours. With blooms recorded in 11 different years here, take particular care at Waneta Lake in June, August and September.
- Keep your dog on a lead near water that looks green, scummy, foamy or discoloured, and away from algae washed up on the shore.
- If your dog gets in, rinse it straight away with clean water and don't let it lick its coat.
- Call a vet immediately if your dog vomits, drools, has diarrhoea, staggers, shakes or seems weak after being near the water.
Read the full guide to toxic algae and dogs: symptoms, what to do in the first minutes and how vets treat it.
Health effects of toxic algae
Blue-green algae (cyanobacteria) can produce toxins that affect the liver, nervous system and skin. Swallowing water during a bloom can cause stomach pain, vomiting and diarrhoea. Skin contact can cause rashes, and breathing spray from the water can irritate the eyes, nose and throat. Children are at higher risk because they are smaller and more likely to swallow water.
How to spot a bloom
Toxic blooms can look like pea soup, spilled paint or green streaks on the surface, and they can also be blue, brown, white or red. Scum often collects along the shore downwind. If you can't see your feet in knee-deep water, or you aren't sure, stay out.
Don't drink untreated lake water, and don't boil it to make it safe: boiling doesn't destroy algal toxins. If you feel unwell after contact with the water, contact a doctor or Poison Control on 1-800-222-1222.
Nearby lakes with algae reports
- Lamoka Lake Channel3 km away, 3 reports, last in 2023
- Lamoka Lake5 km away, 7 reports, last in 2025
- Keuka Lake6 km away, 10 reports, last in 2025
- Seneca Lake18 km away, 23 reports, last in 2025
- Lake Salubria20 km away, 5 reports, last in 2023
Questions about Waneta Lake
Is there algae in Waneta Lake right now?
Waneta Lake was on New York's harmful algal bloom list from 20 June 2025 to 23 September 2025, with confirmed bloom status (16 reports). New York publishes its data once a year, so for today's conditions check the NYHABS map and the signs at the shore.
When was the last algae bloom at Waneta Lake?
The most recent entry in New York's data is from 20 June 2025: a confirmed bloom.
Has Waneta Lake had toxic algae before?
Yes. Blooms are recorded in 11 of the 14 years from 2012 to 2025, most often in June, August and September.
Can dogs swim in Waneta Lake?
Keep dogs out of the water whenever a bloom is reported or the water looks green, scummy or discoloured. Dogs are the animals most often killed by algal toxins because they swallow water and lick their fur. If your dog swims in water that might have algae, rinse it with clean water and call a vet if it vomits, drools, staggers or seems weak.
Can you eat fish caught in Waneta Lake during a bloom?
If you keep fish caught during a bloom, health agencies advise removing the guts and liver and rinsing the fillets in clean water before cooking, because toxins collect most in the organs. Some agencies advise not eating fish from an active bloom at all, so follow local guidance.
About this data
This page uses official records from the New York State Department of Environmental Conservation (DEC), which published as a yearly summary; the current season is shown on the NYHABS map. Reports are grouped by waterbody, and Waneta Lake combines reports from Schuyler County and Steuben County. The site was last rebuilt on 24 October 2026.
States only test some lakes, some of the time, so a lake without a recent report hasn't necessarily been checked. This page is independent, isn't affiliated with the State of New York, and isn't health advice. View the source data.