Harmful Cyanobacterial Bloom (HCB) Recreational Use Bloom Advisory: Leazenby Lake (Hundred Springs Reservoir)

Wyoming Department of Environmental Quality  | view as a webpage

Wyoming Department of Environmental Quality

Harmful Cyanobacterial Bloom (HCB) Recreational Use Bloom Advisory: Leazenby Lake (Hundred Springs Reservoir)

The Wyoming Department of Health has issued a recreational use bloom advisory for Leazenby Lake due to a harmful cyanobacterial bloom (HCB). HCBs are also referred to as harmful algal blooms (HABs) since cyanobacteria are commonly known as blue-green algae. The Department of Health issues advisories w HCBs may also pose a health risk to animals. Bloom advisories are issued when a HCB is present and toxins may be present. Toxin advisories are issued when cyanotoxins exceed recreational thresholds. Lakes and reservoirs under an 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.

On July 15, 2021, the Wyoming Department of Environmental Quality visited the reservoir and observed a potential bloom at the south beach. Water samples were collected at the south beach and cyanobacteria densities exceeded the 20,000 cells/mL recreational use threshold identified in Wyoming’s HCB Action Plan. Cyanotoxin results are pending. The Wyoming Department of Health is working directly with the resource management agency to ensure that signs are posted at the lake. The status of advisories in Wyoming as well as other HCB resources can be found at WyoHCBs.org.

If you encounter a potential HCB, the Wyoming Department of Health and Wyoming Livestock Board recommend the following:

  • 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 Courtney Tillman, Surveillance Epidemiologist, Wyoming Department of Health, at courtney.tillman@wyo.gov or (307) 777-5522.

Questions regarding cyanobacteria sampling can be directed to Kelsee Hurshman, Natural Resource Analyst, Wyoming Department of Environmental Quality, at kelsee.hurshman1@wyo.gov or (307) 777-2073.