Gem State Roundup

Public health advisory issued for Lake Lowell after cyanobacteria detected in water 

By: - September 6, 2022 2:40 pm
Cyanobacteria water

Cyanobacteria blooms occur when blue-green algae rapidly grows out of control. (Courtesy of Lorraine Backer/Centers for Disease Control and Prevention public health image library)

Officials with Southwest District Health have issued a public health advisory for Lake Lowell after detecting high concentrations of a toxin-producing cyanobacteria in water samples. 

The cyanobacteria can be harmful to people, pets and livestock, so public health officials are advising people and their pets to stay out of the water, including avoiding swimming and wading. People should also avoid drinking or cooking using water containing a bloom. Boiling and filtering the water will not remove the toxins and may increase the health risks, public health officials said in a press release issued Friday.

Located near Nampa in Canyon County, Lake Lowell is a popular spot for fishing, water sports and boating that includes 28 miles of shoreline in the Deer Flat National Wildlife Refuge. 

Cyanobacteria occur naturally in Idaho’s waters, but when temperatures rise, they can bloom and release toxic chemicals into the water, Southwest District Health officials said. Blooms may vary in appearance and can look like surface scum, foam, spilled paint or mats and carry a foul odor. 


Anyone handling fish caught from water experiencing a bloom in Lake Lowell should wash their hands thoroughly in clean water, officials said. People should wash their skin or pet’s fur with clean water as soon as possible after coming in contact with contaminated water. 

Officials said the toxins can accumulate in fish, and the risk to people is still being studied. They advised anyone who chooses to eat a fish to clean and wash it thoroughly in clean water, filet the fish and remove and dispose of the fat, skin and organs before cooking.

The cyanobacteria was detected in recent water samples taken by the Idaho Department of Environmental Quality. Public health officials said that anyone with kidney or liver problems is at an increased risk for illness. 

Symptoms of exposure to the toxins include vomiting, diarrhea, rashes, hives and wheezing or coughing, while more severe symptoms can affect the liver and nervous system if water is ingested. Public health officials urge people to call a doctor or health care provider if symptoms persist or are severe. 

Animals are especially susceptible to the toxins, Southwest District Health officials said. Pets and livestock can become sick or die within minutes of going in or drinking the contaminated water. Public health officials recommend contacting a veterinarian immediately if an animal appears sick after going in or drinking contaminated water.  

Public health officials said they will issue a new advisory once testing shows the levels of toxins are likely no longer a concern. 


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Clark Corbin
Clark Corbin

Clark Corbin has more than a decade of experience covering Idaho government and politics. He has covered every Idaho legislative session since 2011 gavel-to-gavel. Prior to joining the Idaho Capital Sun he reported for the Idaho Falls Post Register and Idaho Education News. His reporting in Idaho has helped uncover a multimillion-dollar investment scam and exposed inaccurate data that school districts submitted to the state.