Is Agawam Lake safe? Toxic algae status

Suffolk County, New York. Harmful algal bloom (blue-green algae) reports from the New York State Department of Environmental Conservation (DEC).

Data checked 24 October 2026. New York data is published as a yearly summary; the current season is shown on the NYHABS map.

13 of 13

years on the state's bloom list (2013–2025)

6

years with a confirmed high-toxin bloom (recorded 2012–2018)

2013

first year a bloom was listed

Year by year

Each year the lake appeared on the state bloom list, with its highest status.

2013 High toxins
2014 High toxins
2015 High toxins
2016 High toxins
2017 High toxins
2018 High toxins
2019 Confirmed
2020 Confirmed
2021 Confirmed
2022 Confirmed
2023 Confirmed
2024 Confirmed
2025 Confirmed
Confirmed bloom, high toxinsConfirmed bloom

Reports at Agawam Lake are most often logged in January, May and June.

Recent reports

DateResult
28 May 2025 – 18 November 2025 Confirmed bloom
20 June 2024 – 19 November 2024 Confirmed bloom
24 May 2023 – 15 November 2023 Confirmed bloom
23 May 2022 – 25 October 2022 Confirmed bloom
6 January 2021 – 19 December 2021 Confirmed bloom
22 May 2020 – 17 November 2020 Confirmed bloom
25 June 2019 – 11 November 2019 Confirmed bloom
25 May 2018 – 26 October 2018 Confirmed bloom, high toxins
26 May 2017 – 27 October 2017 Confirmed bloom, high toxins
10 June 2016 – 4 November 2016 Confirmed bloom, high toxins
22 May 2015 – 30 October 2015 Confirmed bloom, high toxins
28 May 2014 – 24 October 2014 Confirmed bloom, high toxins

What the results mean

Suspicious bloom

Reported to the state but not yet confirmed as blue-green algae.

Confirmed bloom

State staff confirmed a blue-green algae bloom from photos or samples. Avoid contact with the water where the bloom is.

High toxins

Toxin levels high enough to be a health concern. Recorded separately in the 2012–2018 data.

Dogs and toxic algae

Dogs face the greatest risk because they swallow water and lick algae off their fur. If a bloom has been reported, keep dogs out of the water and away from scum on the shore. If your dog swims in water that might have algae, rinse it with clean water straight away and call a vet if it seems unwell.

Common questions

Is Agawam Lake safe to swim in?

The most recent entry in New York's published data is from 28 May 2025: confirmed bloom. Blooms have been recorded at Agawam Lake in 13 different years, so treat green, scummy or discoloured water with caution. For current conditions, check the NYHABS map and posted signs.

When does Agawam Lake get algae blooms?

In the state's records, reports are most often logged in January, May and June. Blooms are most likely in warm, calm weather, but they can appear at other times of year.

Source: New York State Department of Environmental Conservation (DEC), official data. This page is independent and not affiliated with the State of New York.