An aerial view of Big Bear Lake. It is a blue bird day and green pine forests surround the blue lake.

Lake Safety - Algae Information

Posted: 07/12/22

The Big Bear Lake Visitor Center occasionally gets questions about blue-green algae and algal blooms in Big Bear Lake. Please see below for the latest information from the Big Bear Municipal Water District (BBMWD) regarding the 2022 summer season. For further questions, please refer to their algae information page or call 909-866-5796.

From the BBMWD -

"Blue-Green Algae is in fact not an algae at all, it is a bacteria (cyanobacteria). This type of bacteria is found in many lakes, ponds, and reservoirs across the world. They are usually present in low numbers, but can become very abundant in warm, shallow, undisturbed surface water that receives a lot of sunlight. When this occurs, they can form “blooms” that discolor the water or produce floating mats or scums on the surface. Although blue-green algae blooms can create nuisance conditions and undesirable water quality, most are not toxic.

So what is a toxic bloom? Some forms of blue-green algae produce toxins, when these toxic blooms die and decay some toxins may be released into the water. When a body of water contains enough of these toxins to pose a risk to humans, animals, and the environment, they are referred to as harmful algae blooms (HABs). Currently, the east side of the Lake off of Stanfield cutoff is labeled as an area to use caution. If Big Bear Lake has a bloom that is considered toxic, the District will make sure to educate the public and post signs in the affected area. If signs are posted, please abide by them.

The time of concern is only during hot summer months and if concerned, swim another day or not at all. The District recommends that if the water looks questionable, simply look for cleaner, bluer water. If in doubt, stay out! If you believe you or your pet were in water of concern, feel free to wash yourself and/or pet off at our washing station at our East Public Launch Ramp facility or at home. Pets are more susceptible to algal cells that are ingested while trying to cool down on a hot summer day by taking a swim in the Lake. Some pets tend to drink large amounts of lake water while playing, or maybe they clean themselves off after a day out in the water. That’s why it’s always a good idea to rinse yourself and your pet off after getting in any body of water.

For the latest updates check our website, which is updated as water quality changes. Another useful website to check is The latest testing results have been added to this post below."