A sign posted in 2022 at Indian Creek Reservoir warns visitors of toxins produced by blue-green algae.
Photo by Kurt Hildebrand.
An algal bloom has prompted posting parts of Indian Creek Reservoir in Alpine County as dangerous.
“Localized areas of the lake were tested to confirm that the lake is being impacted by Harmful Algal Blooms,” according to the Lahontan Regional Water Quality Control Board. “The lake is posted with a lakewide recreational advisory of “danger” to alert lake users of the elevated risk.”
Warm conditions tend to encourage poisonous algae growth in several Sierra lakes. Crowley Lake in southern Mono County was also subject to a danger warning.
The board is urging anglers and recreational users to stay out of, not let pets drink from or eat fish caught from the water.
Visitors shouldn’t use the water for drinking or cooking, as neither filtering nor boiling will make it safe.
Do not use this water for drinking or cooking. Boiling or filtering will not make the water safe.
Indian Creek Reservoir is routinely monitored by South Tahoe Public Utility District.
On Aug. 22, staff observed a harmful algal bloom with a spilled paint appearance. Monitoring results confirmed toxins are present at a danger level threshold at all three of the areas monitored. The advisory has been issued for the entire lake.
Cyanobacteria is a group of organisms that form harmful algal blooms, can produce potent toxins. Dermatoxins can cause skin inflammation, which can cause itching skin and rashes, as well as gastrointestinal distress, headaches, agitation and weakness, or abnormal breathing if 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 and brown.
Advisory signs to notify recreational users of the bloom have been posted.
