Idaho Recreational Waters

The Idaho Division of Public Health and Idaho’s local public health districts work together to investigate outbreaks of illness associated with drinking or recreational water as well as provide information about well water safety and Harmful Algal Blooms in the area.  

Mucky, green water at Henrys Lake caused by cyanobacterial bloom
Idaho Recreational Water Health Advisories
Harmful algal blooms

Harmful algal blooms (HABs) are made of cyanobacteria that can produce toxins which can harm humans and animals. HABs can occur in waterbodies in Idaho when water temperatures and nutrients increase, and cyanobacteria rapidly increase in number producing a bloom. Blooms can be blue, bright green, brown, or red and may look like paint, foam, scum, or mats on the surface of freshwater lakes and ponds.

People and animals can be exposed to HAB toxins by swallowing or touching the water during recreational activities, such as fishing, swimming, water skiing, or when eating fish from a bloom. Exposure to HABs may cause skin and eye irritation, nausea, vomiting, and sometimes death. Keep your family and pets safe by avoiding water with a bloom.

Recreational water

The Idaho Division of Public Health works with Idaho’s local public health districts to investigate outbreaks of illness associated with drinking or recreational water. 

Recreational waterborne illnesses result from swallowing, breathing, or having contact with recreational water. Recreational water is any water which is used by a significant number of persons for recreation or play such as in natural or artificial bodies of water and man-made facilities.

Recreational water use is associated with significant benefits to health and well-being. Yet the Centers for Disease Control and Prevention has noted a steady increase in the number of reported outbreaks of diarrheal illness associated with recreational waters. These reports suggest that spread of illness through aquatic venues occurs routinely during the swimming season.


Recreational water resources