Harmful Algal Blooms Home

Harmful algal blooms occur when normally occurring cyanobacteria in the water multiply quickly to form visible colonies or blooms. These blooms sometimes produce potent cyanotoxins that pose serious health risks to humans and animals.Although most algal blooms are not toxic, some types of cyanobacteria produce nerve or liver toxins. Toxicity is hard to predict in part because a single species of algae can have both toxic and non-toxic strains, and a bloom that tests nontoxic one day can be toxic the next.

Real-Time Monitoring Networks

Check 2019 Monitoring Updates

Track monitoring updates as they are posted.

Protect Yourself

Learn about health risks to people and pets exposed to algal blooms and what you can do to recreate safely.

Learn About HABs

Got questions? Find more info about harmful algal blooms.

Find Guidance Documents

Retrieve helpful guidance documents and response plans. For agencies responding to harmful algal blooms.


Signage & Handouts

Go to Response Agency Resources for more resources.

Warning Sign

Danger. Closed due to toxic algae. Keep out of water.

Danger Sign

HABs info card front
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HABs info card back
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Report a Bloom

24-Hour DEQ Environment Incidents Line: (801) 536-4123

Call Utah Poison Control Center

If you believe you or your pet have been exposed to a harmful algal bloom, call (800) 222-1222.

Click the map icons for details.

2019 Advisories/Updates

Location Last Sample Date Advisory Level
Blackridge Reservoir August 6, 2019 Warning
Calder Reservoir August 6, 2019 Warning
Jordan Narrows August 13, 2019 Warning: Jordan Narrows, Blackridge Reservoir
Manning Meadow Reservoir August 9, 2019 Warning
Mantua Reservoir August 15, 2019 Warning
Matt Warner Reservoir August 6, 2019 Danger
Payson Lakes July 25, 2019 Warning: McClellen Lake, Box Lake
Utah Lake August 8, 2019 Warning: Lincoln Beach, Provo Bay, Goshen Bay
Upper Box Creek Reservoir August 9, 2019 Warning
Wheeler Farm July 30, 2019 Warning
Yuba Lake August 9, 2019 Warning

Get BloomWatch App

Help us track cyanobacteria blooms with your smartphone. Go to cyanos.org for more info.