Harmful Algal Bloom

Rye Patch Reservoir has been placed on a HAB Watch advisory as of 5/28/2026 following visual observation and satellite imaging of a surface bloom. Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

Lahontan Reservoir has been placed on a HAB Watch advisory as of 5/11/2026 following visual observation and satellite imaging of a surface bloom. Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

On 5/19/26 the Walker Lake HAB advisory level has been lowered from a HAB Warning to a HAB Watch based on the most current data and observations collected by NDEP. Hazardous conditions are possible or present. People and pets should use caution when in contact with water and avoid areas of algae accumulation.

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.

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