Is the lake safe?

Chautauqua County, New York

Chautauqua Lake algae bloom status

Confirmed bloom

2025 season, the latest published by New York

Is Chautauqua Lake safe to swim in?

Chautauqua Lake was on New York's harmful algal bloom list from 26 May 2025 to 14 October 2025, with confirmed bloom status (56 reports). Blooms are a recurring problem here: toxic algae has been reported every year from 2012 to 2025, most often in May, June and July.

Avoid contact with green, scummy or discoloured water and keep dogs out of it.

Check today on the NYHABS map
Years with blooms
14 of 14
Usual months
May, Jun and Jul
High-toxin years
7 2012–18
Data checked
24 October 2026

Chautauqua Lake algae bloom history

New York's Department of Environmental Conservation listed Chautauqua Lake as having a harmful algal bloom every year from 2012 to 2025.

In 7 years, a bloom here was confirmed with high toxin levels, the most serious category the state recorded (tracked from 2012 to 2018).

Blooms were confirmed by state staff in 14 years; in the other years they were reported as suspicious but not confirmed.

Blooms have been recorded every year for the last 14 years in the data.

That puts Chautauqua Lake 2nd of the 352 New York lakes on this site for the number of years with blooms.

  1. 2012 High toxins, 9 reports
  2. 2013 High toxins, 11 reports
  3. 2014 High toxins, 11 reports
  4. 2015 High toxins, 8 reports
  5. 2016 High toxins, 12 reports
  6. 2017 High toxins, 15 reports
  7. 2018 High toxins, 17 reports
  8. 2019 Confirmed, 72 reports
  9. 2020 Confirmed, 49 reports
  10. 2021 Confirmed, 47 reports
  11. 2022 Confirmed, 61 reports
  12. 2023 Confirmed, 33 reports
  13. 2024 Confirmed, 74 reports
  14. 2025 Confirmed, 56 reports
Confirmed bloom, high toxinsConfirmed bloom

When do algae blooms happen at Chautauqua Lake?

At Chautauqua Lake, reports are most often logged in May, June and July.

About 93% 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.

January: 0% of reports
February: 0% of reports
March: 7% of reports
April: 0% of reports
May: 29% of reports
June: 43% of reports
July: 21% of reports
August: 0% of reports
September: 0% of reports
October: 0% of reports
November: 0% of reports
December: 0% of reports
Share of reports by month. Darker bars are the peak months.

Recent Chautauqua 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.

DateResult
26 May 2025 to 14 October 2025 Confirmed bloom
15 June 2024 to 7 October 2024 Confirmed bloom
31 May 2023 to 1 October 2023 Confirmed bloom
11 June 2022 to 24 October 2022 Confirmed bloom
22 May 2021 to 15 October 2021 Confirmed bloom
16 June 2020 to 20 September 2020 Confirmed bloom
30 June 2019 to 20 October 2019 Confirmed bloom
25 May 2018 to 13 October 2018 Confirmed bloom, high toxins
25 June 2017 to 27 October 2017 Confirmed bloom, high toxins
11 July 2016 to 28 October 2016 Confirmed bloom, high toxins
7 March 2015 to 20 October 2015 Confirmed bloom, high toxins
30 June 2014 to 20 October 2014 Confirmed bloom, high toxins

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 Chautauqua 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 14 different years here, take particular care at Chautauqua Lake in May, June and July.

  • 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.

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

All Chautauqua County lakes with algae reports

Questions about Chautauqua Lake

Is there algae in Chautauqua Lake right now?

Chautauqua Lake was on New York's harmful algal bloom list from 26 May 2025 to 14 October 2025, with confirmed bloom status (56 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 Chautauqua Lake?

The most recent entry in New York's data is from 26 May 2025: a confirmed bloom.

Has Chautauqua Lake had toxic algae before?

Yes. Blooms are recorded every year from 2012 to 2025, most often in May, June and July.

Can dogs swim in Chautauqua 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 Chautauqua 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. 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.