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With warmer weather and abundance of water, we may be seeing an increase of possible Harmful Algal Blooms (HABs). Harmful algae can produce toxins that hurt people, animals, and the environment. There have been twelve possible reports of HABs in 2024.

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2024

Active HAB Reports

Lake Mohave – Eagle Wash Cove, Placer Cove, and Morning Star Cove

An HAB Watch advisory has been placed on Lake Mohave.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation. Human or animal contact with visible blooms is discouraged. Prevent pets from entering the water, drinking water, or coming in contact with any scum found on the shore.

The areas of Lake Mohave Eagle Wash Cove, Placer Cove, and Morning Star Cove will remain on an HAB Warning advisory until at least two water tests in a row indicate cyanotoxin levels below the Warning advisory threshold. Conditions in these areas can be unsafe for human and animal exposure. 

Lahontan Reservoir

Lahontan Reservoir has been placed on HAB Danger Advisory after water tests showed high Microcystin levels above the safety threshold.

Stay out of the water. Human or animal contact with water is strongly discouraged. The condition of the water body is expected to be unsafe for human and animal exposure. Protect your pets from entering the water, drinking water or coming in contact with any scum found on the shore.

Stillwater National Wildlife Refuge

The HAB Watch Advisory has been liftedNo bloom advisory in place.


There is a HAB Watch advisory in place for Stillwater National Wildlife Refuge. Any water body can be affected, but extra caution is advised at the following: Willow Lake/West Marsh, Lead Lake, Swan Lake, Swan Check, Pintail Bay, Goose Lake, North Nutgrass Lake, South Nutgrass Lake, and West Nutgrass.

Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

 

Weber Reservoir

The HAB Watch Advisory has been lifted No bloom advisory in place.


There has been a report of a possible HAB at Weber Reservoir.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Nevada Beach Pond

The HAB Watch Advisory has been lifted.  No bloom advisory in place.

Big and Little Washoe Lakes

The HAB Watch Advisory has been liftedNo bloom advisory in place.


There has been a report of a possible HAB at Big and Little Washoe Lakes.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

South Fork Reservoir

The HAB Watch Advisory has been liftedNo bloom advisory in place.


There has been a report of a possible HAB at South Fork Reservoir.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Wild Horse Reservoir

The HAB Watch Advisory has been liftedNo bloom advisory in place.


There has been a report of a possible HAB at Wild Horse Reservoir.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Eagle Valley Reservoir

The HAB Watch Advisory has been lifted No bloom advisory in place.


There has been a report of a possible HAB at Eagle Valley Reservoir in Spring Valley, NV.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Chimney Reservoir

The HAB Watch Advisory has been liftedNo bloom advisory in place.


There has been a report of a possible HAB at Chimney Reservoir.

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Virginia Lake

The HAB Watch Advisory has been liftedNo bloom advisory in place.


Virginia Lake has been downgraded to a HAB Watch

Advisory Recommendations: Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Tips and Information about HABs

Signs that there may be an HAB in the water:

  • The water smells rotten
  • The water looks like paint
  • Large mats or scums are floating on surface
  • There are bright colors like blue, green, white, brown or red

The Nevada Division of Public and Behavioral Health (DPBH) is working with Nevada Division of Environmental Protection, Nevada State Parks and the Nevada Department of Wildlife to ensure the health and safety of Nevadans and their pets who may visit locations where a Harmful Algal Bloom (HAB) has occurred.

If a HAB is suspected, individuals should take the following precautions:  

  • Do not allow pets to play in or drink water during a bloom
  • Do not swim or play in water with a bloom
  • Do not drink, cook with or wash dishes with affected water

People exposed through direct skin contact, ingestion or inhalation may experience irritation of the skin, eyes, nose, throat, and/or respiratory tract. Symptoms to look for include: 

  • Rashes, hives, or blisters
  • Runny nose, sore throat, asthma, or allergic-like reactions

People exposed through ingesting cyanotoxins may experience: 

  • Abdominal pain
  • Headache
  • Neurological symptoms
  • Vomiting
  • Diarrhea
  • Liver damage and/or kidney damage

For more information and tips about HABs visit Environmental Health | The Office of State Epidemiology. Individuals who believe they may be experiencing symptoms of exposure to algal toxins should contact their local health care provider or contact the Poison Control Center: 1-800-222-1222.

Dashboard

To keep current with advisory recommendations, click here to access our dashboard

Previous HAB Reports

2023

There were four reports of HABs the summer of 2023.

Washoe Lake 

There has been a report of a possible HAB at Washoe Lake, south of Reno. The public, including pets, are advised not to swim or enter the water at Big or Little Washoe Lake.

Lahontan Reservoir 

There has been a report of a possible HAB at Lahontan Reservoir. The public, including pets, are advised not to swim or enter the water.

Wild Horse Reservoir

There has been a report of a possible HAB at Wild Horse Reservoir. The public, including pets, are advised not to swim or enter the water.

South Fork Reservoir

There has been a report of a possible HAB at South Fork Reservoir. The public, including pets, are advised not to swim or enter the water.