Current Status of Lake Elsinore

August 30, 2018 – Cyanobacteria Toxins Elevated, Precautions Urged

On Wednesday, August 22 the State Water Quality Control Board conducted water sampling for Cyanobacteria (blue-green algae) toxins in seven locations on Lake Elsinore. All samples indicated high levels of microcystins that exceeded the recommended danger trigger threshold. Per the State Water Quality Control Board’s recommendations, the City has posted the State’s danger signs at 27 locations around the lake.

Currently, Lake Elsinore remains open to all recreational uses including boating, fishing, kayaking and more. Harmful algae blooms and related toxins are primarily harmful through ingestion. Therefore, visitors are encouraged to use discretion while recreating on Lake Elsinore and the following precautions are recommended based on the State’s Voluntary Statewide Guidance for Blue-Green Algae Blooms:

  • DO NOT SWIM OR WADE near algae and/or scum.
  • After coming in contact with the water, RINSE OFF WITH FRESH WATER as soon as possible.
  • KEEP CHILDREN AWAY from algae in the water and on the shore.
  • Warn young children NOT TO SWALLOW any lake water, whether or not you see signs of algae.
  • DO NOT DRINK the water or use it for cooking.
  • DO NOT LET PETS OR LIVESTOCK drink the water or ingest scum on the shoreline.
  • For fish, THROW AWAY GUTS AND CLEAN FILLETS with tap water or bottled water before cooking. COOK THOROUGHLY.
  • If you or your pet get sick after going in the water, contact your doctor or veterinarian.

Possible symptoms for human exposure to Cyanobacteria toxins may include sore throat or congestion; coughing, wheezing, or difficulty breathing; red or itchy skin or rash; earache or irritated eyes; diarrhea or vomiting; agitation; headache; and/or abdominal pain. Read more.

Animals can experience symptoms within minutes to days following exposure to the cyanobacterial toxins. Symptoms they might experience include vomiting, diarrhea, weakness, difficulty breathing, seizures, or death. In 2017, there were 18 reported dog deaths from suspected HAB-related exposures in California. Read more.

Lake Elsinore is Southern California’s largest natural, freshwater lake. At 3,000 acres, the lake evaporates quickly with the lake level falling by more than two and a half feet per year. The lake remains well below its optimal lake level and remains extremely vulnerable to algae blooms during the hot summer months.

To ensure the safety of visitors to Lake Elsinore, permanent ‘Caution’ signs have been placed all around the lake regarding the risks of blue-green algae. 

Blue-green algae is present in most freshwater and marine aquatic ecosystems. Excessive growth of blue-green algae can lead to these types of algae blooms, which can be harmful. Blue-green algae (cyanobacteria) can release harmful toxins as the algae die off. Historically, Lake Elsinore has experienced algae blooms, which are very common during the summer months when temperatures increase. Algae blooms are common in other natural waterbodies around the country. As the algae die off, toxins can be produced. Concerns regarding blue-green algae have been on the rise throughout the Country.

Information on the City’s website will be updated appropriately. Updates regarding Lake Elsinore can be found at

For more information, please contact Nicole Dailey at (951) 674-3124 ext. 314 or

Helpful Harmful Algae Bloom (HAB) Links

HAB Incidents Reports Map

HAB Data Viewer

State Water Quality Control Board Frequently Asked Questions (FAQs)  

What Does A Cyanobacteria Bloom Look Like

About Lake Elsinore's Health 

Lake Elsinore is Southern California’s Largest Natural, Freshwater Lake. Faced with a historic drought, extremely low water levels, higher temperatures, and an abundance of shad, the City has become increasingly concerned about the health of the lake and the vitality of the fishery.

In 2015, in an effort to be proactive and prepared, the City partnered with the Lake Elsinore & San Jacinto Watersheds Authority (LESJWA) launched Lake Watch 2015 to create awareness and engage the community, local and regional resource agencies and private businesses to take part in our efforts to prepare for and address the vulnerability of Lake Elsinore.

The City started its Lake Watch efforts to get prepared and regularly inform the community about the health and concerns of our most valuable asset - Lake Elsinore. While the City and the Elsinore Valley Municipal Water District each spend more than $750,000 per year to add 5 million gallons of recycled water to the lake each day, it is not enough to offset evaporation. In 2016, lake's water level declined to its lowest levels since early 1993 and was extremely vulnerable to algae blooms and subsequent fish kills. At this time, we suffered our first detected blue-green algae bloom.

In 2017, storms helped to replenish the lake and the water quality greatly improved. However, 2018 was amongst one of our driest years on record and the lake levels have once again declined well below the optimal level of 1240’. Ultimately, the lake needs more rain and the City remains diligent in monitoring the lake's health and working toward long-term options to improve the overall health of Lake Elsinore. 

Algae & Algae Blooms 

Algae are large photosynthetic organisms and are normal habitats of large bodies of water like a lake. Algae are very important to both freshwater and marine environments and most species are harmless under normal circumstances. Cyanobacteria are known as “blue-green algae” are actually bacteria and not a form of Algae. Algae and Cyanobacteria have very similar characteristics with the difference that certain Cyanobacteria toxins can be harmful to the environment, animals and human health.

Algae blooms occur when the algae grow at rapid speeds than normal causing dense accumulations in the water. Algae blooms are normal occurrences in bodies of water. They can become harmful when there is excessive growth. As the cyanobacteria die off, harmful toxins can be produced known as cyanotoxins Concerns regarding blue-green algae have been on the rise throughout the Country and California including Pyramid Lake, Discovery Bay, Lake Elsinore, and Silverwood Lake. 

Read more on Algae Blooms 

Fish Kills 

In 2015, a fish survey conducted on behalf of LESJWA found that Lake Elsinore’s fishery is imbalanced due to an overpopulation of Threadfin Shad. Shad are small, highly sensitive fish that hinder the water quality by eating microscopic zooplankton, which consume algae. With Shad feeding on the zooplankton in the lake, there will likely be an algae bloom thus reducing dissolved oxygen. Such conditions, ultimately lead to the demise of this delicate fish. It is nature’s way to rebalance the fish population and improve the overall health and quality of the lake.

Since 2000, the City and LEJSWA in coordination with its partner agencies have greatly improved water quality and wildlife habitats in Lake Elsinore, as well as in the surrounding watershed. Successful projects to date include the following:

  • Lake Elsinore Wetlands Enhancement Project
  • Lake Elsinore Carp Removal
  • Island Wells Pump Station Improvements
  • Striped Bass Stocking
  • Lake Elsinore Destratification & Mixing System
  • Recycled Water Nutrient Removal & Conveyance Pipeline
  • Lake Habitat Improvements

Despite these efforts, Lake Elsinore is a natural lake. Recent conditions have created a poor ecological condition for the lake that is difficult to sustain. A fish kill is one of Nature’s ways of rebalancing the food chain. While there is no indication currently that an event is imminent, the probability is high. 

In 2015 and 2018, Lake Elsinore did suffer a moderate fish kill. The City remains prepared and regularly monitors the dissolved oxygen in the lake for signs of concern.

Lake Watch

Lake Elsinore is an extremely complex, unique water body. It is a show lake that struggles due to increasing temperatures, recent algae blooms, and declining dissolved oxygen levels during the hotter months. Unfortunately, there is little the City or LESJWA can do to improve its current condition without a stable and reliable water level of above 1240'. 

Lake Watch is focused on ensuring the City, regional partners and the community is ready and prepared for any potential concerns related to the vulnerability of Lake Elsinore including declining lake levels, algae blooms and the potential of a fish kill.  

As part of Lake Watch, the City of Lake Elsinore and LESJWA asks the community and visitors to monitor the lake and notify the City should you notice anything abnormal including algae blooms or dead fish floating in the lake or washed up on shore.

To report, please call 951-674-3124 ext. 204, email or message the City at