For Immediate Release:  June 24, 2021


Jonathan Oppenheimer, External Relations Director, Idaho Conservation League, (208) 867-3505

Laura Pinover, Communications and Engagement Assistant, Idaho Conservation League, (208) 286-4780 


Early Algae Outbreak Reported at Lake Cascade

Keep your family, friends, and pets safe this summer


CASCADE – With deepening droughts and summer heat settling across Idaho, Friends of Lake Cascade have reported the first seasonal algal outbreak in the Boulder Creek Arm Tributary.

Algal outbreaks can be toxic and harm humans, pets, and other wildlife. When outbreaks occur, officials recommend recreators restrain from drinking, swimming, or walking near water where an outbreak is occurring. 

“This is one of the earliest outbreaks we have seen in the area,” said Lenard Long, a Friends of Lake Cascade member. “We need to work together to reduce contaminants in our water.”

Harmful bacteria from the outbreaks can create toxins when conditions are right. Last week, when this outbreak was identified, the Idaho Department of Environmental Quality determined that they were not yet producing toxins. As a result, DEQ and the local health district have not yet issued a warning. However, with the upcoming holiday weekend, Idaho Conservation League would like to stress that toxins can still appear at any time during an outbreak.

“Given warming temperatures and dropping water levels, it’s likely only a matter of time,” noted Jonathan Oppenheimer, ICL’s external relations director. “In fact, this year’s algae growth is showing up one month early.”

The most common causes of algae outbreaks are excess pollutants, such as phosphorus and nitrogen, combined with warm water temperatures. Cyanobacteria is the most common form of toxic algae; it’s typically a blue-green color, but can sometimes take on a reddish-brown hue. While not all algae outbreaks are harmful, ICL and public health officials advise the community and visitors alike to act cautiously when recreating this summer. 

Help keep your family and friends safe this summer. Keep children and pets away from algal outbreaks and remember to never consume untreated water. If you notice green discolored water, call and report it to DEQ at (208) 373-0570.

Find out more about staying safe by visiting Idaho Department of Environmental Quality’s toxic algae website


The Idaho Conservation League works to protect the air you breathe, water you drink, and wild places you and your family love. We work to make sure our rivers are flowing and are clean enough for people and fish to thrive. ICL also works to protect our groundwater, as that’s where the majority of Idahoans get their drinking water. 

Friends of Lake Cascade is an environmental conservation organization that strives to improve the quality of Lake Cascade. It is solely run by a dedicated group of volunteers who work to help people understand problems happening around the North Fork Payette River Watershed through education programs and collaboration with local, state, and federal agencies.