News from the Cheyenne Board of Public Utilities:
The Wyoming Department of Health has issued a harmful cyanobacterial bloom recreational use advisory for the West Causeway at the City of Cheyenne Board of Public Utilities’ (BOPU) Granite Springs Reservoir. The reservoir is located about 30 miles west of Cheyenne in Curt Gowdy State Park. The Causeway is an area west of the Granite Springs Reservoir where Middle Crow Creek flows toward the reservoir. The Causeway is separated from the main reservoir by a road.
Cyanobacteria was not detected in the main reservoir, a source for Cheyenne’s drinking water. BOPU states laboratory staff will continue to monitor water quality in Cheyenne’s water sources as of August 5, 2025.
The Wyoming Department of Health has also issued a bloom advisory for Sloans Lake in Cheyenne, warning residents about the increasing risk of blue-green algae blooms. Sloans Lake is used for recreational and irrigation purposes; it is not part of the City of Cheyenne’s drinking water supply.
Blue-green algae tend to form harmful blooms in slow-moving water during the late summer, when water temperatures rise. These blooms can produce toxins and other irritants that pose health risks to humans, pets, livestock, and wildlife.
- Avoid contact with water in the vicinity of a bloom, especially in areas where cyanobacteria may be dense and form a residue.
- Do not ingest water where a bloom may be present. Boiling, using filtration, and/or other treatments will not remove toxins.
- Rinse fish with clean water and eat only the fillet portion.
- Avoid any water spray-off where a bloom may be present.
- Do not allow pets or livestock to drink water near a bloom, eat bloom material or lick fur after contact with a bloom.
- If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible.
You can view a list of current advisories here.