Silverwood Lake Algal Bloom Reduces to Caution Level at Cleghorn Beach


Photo of Silverwood Lake

Silverwood Lake

SACRAMENTO, Calif. Today, the Department of Water Resources (DWR) lowered a warning advisory that had been in effect since October 16 at Silverwood Lake’s Cleghorn Beach in San Bernardino County. Water contact is now allowed, but DWR urges all recreational users to exercise caution and avoid direct contact with blue-green algae.

DWR reduced the advisory from warning to caution at Cleghorn Beach and caution to no advisory at Sawpit Beach after detecting a reduced amount of microcystins. Boating and other water-contact recreation and sporting activities are now allowed. For more information on caution 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.


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:



For more information, follow us on Twitter or Facebook and read our news releases and DWR updates.