The Lahontan Regional Water Quality Control Board (Water Board) is urging fisherman and recreational users to stay out of the water at Bridgeport Reservoir located in Mono County.
Localized areas of the lake were tested to confirm that the lake is being impacted by Harmful Algal Blooms (HABs).
The dam area is posted with a recreational advisory of “DANGER” to alert lake users of the elevated risk. Recreators are encouraged to follow the below guidance until further notice.
• Stay out of the water until further notice, including watercraft.
• Do not let pets and other animals drink or go into the water, or go near the scum.
• Stay away from scum, and cloudy or discolored water.
• Do not eat fish or shellfish from this water.
• Do not use this water for drinking or cooking. Boiling or filtering will not make the
Walker River Irrigation District, a regional partner that assists with monitoring noticed visual observations of a potential bloom while sampling during the Labor Day Pre- Holiday Assessment at Bridgeport Reservoir.
Sample results confirmed toxins were present at levels that exceed the danger level threshold in a sample collected from the dam area. Caution level toxins were present at a second sample collected North of the Bridgeport RV Park.
Note that cyanobacteria, a group of organisms that form harmful algal blooms, can
produce potent toxins. Health risks are associated with HABs as they produce
dermatoxins that can cause skin inflammation, which can cause itching skin and rashes,
as well as gastrointestinal distress, headaches, agitation and weakness, or abnormal
breathing if HAB material is swallowed while swimming. Dogs and children are most
susceptible to exposure because of their smaller body size, increased potential to
swallow water while swimming, and tendency to stay in the water longer. If you suspect
exposure, wash your children and dog immediately. Due to the size and toxicity of the
bloom with increasing temperatures and decreased precipitation this time of year, the
bloom may proliferate and alter its potential to produce toxins.
The bloom occurring in the lake appears suspended on the water’s surface. Bloom
conditions can change rapidly, as the winds and waves move or concentrate the bloom
into different regions of the lake. In some areas, the bloom may concentrate and form a
film or scum on the water surface. The color of the water may also appear discolored as
bright or dark green.
The Water Boards will provide regular updates to inform the community when postings
are removed on the California HAB Reports Web Map.
The Water Boards recommend that people practice healthy water habits
while enjoying the outdoors this summer at your local lake, river or stream:
• Heed all instructions on posted advisories if present
• Avoid algae and scum in the water and on the shore
• Keep an eye on children and pets
• If you think a harmful algal bloom or toxic algal mats are present, do not let pets and
other animals go into or drink the water or eat scum/algal mats on the shore
• Don’t drink the water or use it for cooking
• Wash yourself, your family and your pets with clean water after water play
• If you catch fish, throw away guts and clean fillets with tap water or bottled water
• Avoid eating shellfish if you think a harmful algal bloom is present
Get medical treatment immediately if you think that you, your pet, or livestock has
gotten sick after going in the water. Be sure to alert the medical professional to the
possible contact with cyanobacteria. Also, make sure to contact the local county public
To report a bloom, do one of the following:
• Fill out the Bloom Report form on the HABs Portal:
• Email: [email protected]
• Call the HABs hotline: 1-844-729-6466 (toll free)
• Contact your County Public Health Office