Weston Reservoir (Wyoming DEQ)

CASPER, Wyo. — A new harmful algae bloom advisory was issued in Wyoming on Monday, Aug. 31 for Weston Reservoir in the northern part of the state.

The presence of harmful algae blooms has now been confirmed at a total of 16 Wyoming bodies of water this summer. Three additional lakes or ponds are under investigation, according to the Wyoming Department of Environmental Quality.

Recreational use advisories due to the confirmed presence of cyanobacterial blooms are in effect at the following Wyoming lakes or reservoirs:

  • Weston Reservoir
  • Flaming Gorge Reservoir
  • Brooks Lake
  • Granite Springs Reservoir
  • Pathfinder Reservoir
  • Lower North Crow Reservoir
  • Big Sandy Reservoir
  • Eden Reservoir
  • Woodruff Narrows Reservoir
  • Boysen Reservoir
  • Ocean Lake
  • Saratoga Lake
  • Wheatland Reservoir #3
  • Leazenby Lake
  • Seminoe Reservoir
  • Keyhole Reservoir

The Wyoming DEQ is also investigating possible harmful algae blooms at:

  • Jackson Lake
  • Gillette Fishing Lake
  • Huck Finn Pond

The Wyoming DEQ confirmed the presence of harmful blooms at 16 lakes or reservoirs in 2019. 12 advisories were issued in 2018.

Details regarding the blooms at each body of water is available from the “Harmful Cyanobacterial Bloom (HCB) Advisories in Wyoming Waters” webpage. 

“HCBs are also referred to as harmful algal blooms (HABs) since cyanobacteria are commonly known as blue-green algae,” the Wyoming DEQ explains. “The Department of Health issues advisories to inform the public that there may be health risks for people and animals in areas where HCBs occur.”

Flaming Gorge Reservoir (Wyoming DEQ)
Granite Springs Reservoir (Wyoming DEQ)
Brooks Lake (Wyoming DEQ)

“Lakes and reservoirs under a recreational use advisory are not closed since HCBs may only be present in certain areas of the waterbody and conditions can change frequently. The advisory will remain in place until the bloom has fully dissipated and cyanotoxin concentrations are below recreational use thresholds identified in Wyoming’s HCB Action Plan, or until the primary recreation season ends on September 30th, whichever comes first.”

People who encounter possible harmful blooms are provided the following recommendations from the Wyoming DEQ and Wyoming Livestock Board:

  • Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.
  • Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.
  • Rinse fish with clean water and eat only the fillet portion.
  • Avoid water spray from the bloom.
  • Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.
  • If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.

Questions about health effects and recreational use advisories can be directed to Dr. Karl Musgrave, State Environmental Health Epidemiologist / State Public Health Veterinarian, Wyoming Department of Health, at karl.musgrave@wyo.gov or (307) 777-5825.

Questions regarding cyanobacteria sampling can be directed to Michael Thomas, Natural Resource Analyst, Wyoming Department of Environmental Quality, at michael.thomas@wyo.gov or (307) 777-2073, or Lindsay Patterson, Surface Water Quality Standards Coordinator, Wyoming Department of Environmental Quality, at lindsay.patterson@wyo.gov or (307) 777-7079. Wyoming DEQ

Keyhole Reservoir (Wyoming DEQ)
Pathfinder Reservoir (Wyoming DEQ)
Eden Reservoir (Wyoming DEQ)
Big Sandy Reservoir (Wyoming DEQ)
Lower North Crow Reservoir (Wyoming DEQ)
Saratoga Lake (Wyoming DEQ)
Leazenby Lake (Hundred Springs Reservoir) (Wyoming DEQ)
Wheatland Reservoir #3 (Wyoming DEQ)
Ocean Lake (Wyoming DEQ)
Seminoe Reservoir (Wyoming DEQ)
Boysen Reservoir (Wyoming DEQ)
Woodruff Narrows (Wyoming DEQ)