Lake Users Advised to Avoid Water Contact at Red Lake and Indian
Creek Reservoir Again in 2020
Public Health Advisory – September 27, 2020 – The Alpine County Health Department has been working with The Lahontan Regional Water Quality Control Board, California Department of Fish and Wildlife (Red Lake), South Tahoe Public Utility District (Indian Creek Reservoir), and the Alpine Watershed Group (AWG) in determining that there are levels of toxin associated with blooms of blue-green algae in multiple lakes in Alpine County that are toxic to animals and humans.
Levels at Red Lake have been determined to be well above the “DANGER” level. Levels at Indian
Creek Reservoir have triggered a “WARNING” alert. Both lakes have been posted with the
appropriate warning signs in effect until further notice. Ongoing testing will be conducted on a regular
basis. My prediction (always risky but based on evidence!) is that conditions will get worse before
they get better.
Potential symptoms in dogs following exposure to blue-green algae toxins can include lethargy,
difficulty breathing, salivation, vomiting, urination, diarrhea, or convulsions leading to death. The
unexplained death of a dog after contact with contaminated water is often a sentinel event which
alerts officials to the potential of a toxic bloom. People can experience eye irritation, skin rash, mouth
ulcers, vomiting, diarrhea, and cold or flu-like symptoms, with impacts to the liver. Dogs and children
are most likely to be affected because of their smaller body size and tendency to stay in the water for
longer periods. While there is no antidote for exposures, persons should see their physician and
those with pets which may have been exposed should go to their veterinarian for supportive care.
Livestock who are drinking contaminated water can also suffer fatal consequences.
Blue-green algae (known as cyanobacteria) can be naturally present in any body of fresh water. It
looks like green, blue-green, white or brown scum, foam or mats floating on the water. Warmer air
and water temperatures, high nutrient levels, and slow and stagnant water can cause cyanobacteria
to multiply at an excessive rate and turn in to a harmful algae bloom (HAB). When HABs are present,
the algal scum can be a variety of colors such as fluorescent blue, green white, red or brown. Blooms
can have more than one color present and may look like thick paint floating on the water and give off
a foul odor. HABs may move to different locations of the lake by wind or wave. If you see signs of a
HAB, such as discolored, pea-green water, surface scum, floating algae, stay out of the water.
The State Water Board and the nine Regional Water Boards (known as the Water Boards), in
partnership with other programs and agencies, are actively supporting and coordinating a statewide
HAB incident response with many publicly available resources. In 2018, the Water Boards received
190 voluntary reports of HABs from across the state. To learn how to stay safe around HABs, report a
bloom and more, visit the CA HABs Portal: http://www.mywaterquality.ca.gov/habs/
A popular fishing destination, Red Lake is in Alpine County off Highway 88 near Carson Pass. Visit
the State Water Board Twitter page to see a map and pictures of the cyanobacteria bloom. The
current algal bloom is impacting the entire lake but is most pronounced along the southeast shoreline.
The harmful algal bloom, or HABs, appears as bright pea-green, discolored water with suspended
flecks of material near the surface. As the bloom continues to grow, cyanobacteria colonies may
become larger and form a thick film or scum on the water surface. Bloom conditions in the lake can
change rapidly, as the flow of surface water and wind may mix, move, or concentrate the bloom into
different areas of the lake. The bloom is being tracked by the Lahontan Water Board and Alpine
Watershed Group, which are coordinating to monitor water quality and the occurrence of harmful
algal blooms in Alpine County recreational lakes, including Red Lake. The levels on 9/15/20 were well
above the trigger for a “DANGER” Action Trigger.
Indian Creek Reservoir:
Levels at Indian Creek Reservoir are above the 0.8 µg/L “Caution” Action Trigger level established for
posting signs at recreational waters for the protection of human health. South Tahoe Public Utility
District (STPUD), who manages the property, posted caution signs at Indian Creek Reservoir to warn
lake users to stay away from algae and scum in the water. Testing has revealed that levels are high
enough to trigger a “Warning” Action.
Round Lake – Eldorado National Forest
On 9/11 the CA HABs report also named Round Lake as a area of concern and issued warnings to keep and Dogs and Kids away from Algae along the shoe lines.