Silverwood Lake Algal Bloom: Public Urged to Avoid Water Contact

SACRAMENTO, Calif. – The Department of Water Resources (DWR) is urging the public to avoid contact with water at Silverwood Lake’s Cleghorn Beach in San Bernardino County until further notice due to blue-green algae (cyanobacteria).

Boating is allowed, but swimming and other water-contact recreation and sporting activities are not considered safe at Cleghorn Beach due to potential adverse health effects. Sawpit Beach remains at caution level. For more information on caution and warning level advisories, go to Harmful Algal Bloom website under Advisory Signs.

Advisories are based on the potential health risks from algae. Exposure to toxic blue-green algae, also known as cyanobacteria, can cause eye irritation, allergic skin rash, mouth ulcers, vomiting, diarrhea, and cold- and flu-like symptoms. Pets can be especially susceptible because they tend to drink while in the water and lick their fur afterwards. Keep pets away from the water.

Bloom conditions can change rapidly, and wind and waves may move or concentrate the bloom into different regions of the reservoir. The algal bloom can accumulate into mats, scum, or form foam at the surface and along the shoreline, and range in color from blue, green, white, or brown.

This aerial looks southeast toward Silverwood Lake nestled in the San Bernardino National Forest, formed by the 249 foot high Cedar Springs Dam. The reservoir provides regulatory and emergency storage, and helps firm deliveries to users along the East Branch Aqueduct of the California State Water Project. It also provides recreation, and assures continuity of discharges through Devil Canyon Powerplant. Photo taken May 9, 2014.
Florence Low / California Department of Water Resources

State guidelines on cyanobacteria and harmful algal blooms recommend the following precautions be taken in waters impacted by blue-green algae:

  • Do not let pets and livestock drink the water, swim through algal blooms, scum, or mats, or lick their fur after going in the water. Rinse pets in clean water to remove algae from fur.
  • Avoid wading, swimming, or jet or water skiing in water containing algae blooms, scum, or mats.
  • Do not drink, cook, or wash dishes with untreated surface water from these areas under any circumstances. Common water purification techniques such as camping filters, tablets, and boiling do not remove toxins.
  • Do not eat fish or shellfish from this water.
  • Get medical treatment immediately if you think that you, a family member, friend, pet, or livestock might have been poisoned by blue-green algae toxins. Be sure to alert medical professionals to the possible contact with blue-green algae. Also, make sure to contact the local county public health department.

For more information, visit:

  • California Department of Public Health
  • State Water Resources Control Board
  • CA Office of Environmental Health Hazard Assessment
  • US Environmental Protection Agency: CyanoHAB website
  • Centers for Disease Control and Prevention

Simone Graham – Editor High Desert Gazette

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