Lake Watch
Lake Watch
Lake Elsinore is an extremely complex, unique water body. It is a shallow lake that struggles due to increasing temperatures, algae blooms, and declining dissolved oxygen levels during the hotter months. 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.
Lake Watch - Current State of Lake Elsinore
Update as of January 2, 2026
Based on recent lab results from lake water sampling, the City of Lake Elsinore is announcing that there is no advisory at this time.
Harmful Algae Blooms (HABs) can be highly mobile in a water body and may or may not be visible. As a result, lake users should always practice healthy water habits:
- Avoid algae and scum in the water and on shore.
- Keep an eye on children and pets.
- If you think a HAB is present, do not let pets and other animals go into or drink the water, or eat scum and algal accumulations on the shore
- Don’t drink the water or use it for cooking
- Wash yourself, your family, and your pets with clean water after water play
The City will continue to test the water on a monthly or bi-weekly basis at this time and will post regular updates on the lake conditions as lab results are received.
Launch Pointe RV Resort and the boat launch at Launch Pointe are open for business. Launch Pointe advises all visitors of the current status of the lake. Lake Use Pass Holders will be notified should the terms of their passes be amended.
Lake Level
Lake elevations are expressed in feet above mean sea level. Visit our Guide to How Various Lake Elevations Affect the Lake and Recreation (PDF), to learn more.
View the Current Lake Level website.
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.
Find out more about cyanobacteria (i.e. harmful algae blooms)
FAQs regarding posted signs related to algae blooms
Filamentous Algae
Since April 2024, there has been a noticeable increase in the presence of filamentous algae within Lake Elsinore. Our marine biologists believe that this surge in filamentous algae could be attributed to the recent enhancement in water quality, facilitating greater sunlight penetration to the lake bottom.
Filamentous algae are a common issue in lakes and other freshwater bodies, often leading to aesthetic degradation, ecological imbalance, and water quality deterioration. These algae form dense mats on the water surface, impeding recreational activities, disrupting aquatic ecosystems, and causing undesirable odors.
Filamentous algae, also known as "pond scum," are characterized by their thread-like appearance, forming long strands that intertwine to create mats on the water surface. They thrive in nutrient-rich environments, particularly those with elevated levels of phosphorus and nitrogen. These nutrients often originate from runoff containing fertilizers, sewage, or agricultural waste, fueling the rapid growth of filamentous algae populations.
The growth of filamentous algae can have detrimental effects on lake ecosystems. Dense mats of algae block sunlight from penetrating the water, hindering photosynthesis and suppressing the growth of beneficial aquatic plants. This reduction in plant life diminishes habitat complexity, disrupts food chains, and impairs fish and wildlife populations. Additionally, as filamentous algae die off and decompose, they consume dissolved oxygen, leading to hypoxic conditions that further stress aquatic organisms.
Phoslock
The City is presently in the planning phase of implementing Phoslock to mitigate algae blooms in Lake Elsinore. We aim to initiate our Phoslock pilot project by June 2024, as part of our proactive approach to address the challenges posed by excessive algal growth.
Phoslock is a chemical used to mitigate the growth of algae in lakes. It functions by binding with dissolved phosphorus in the water column, effectively reducing its availability for algal growth. Phoslock is composed of lanthanum-modified bentonite clay granules, which have a high affinity for phosphorus ions. Upon application, Phoslock forms a layer on the lake bottom, where it gradually releases lanthanum ions to sequester phosphorus from the water.
Phoslock specifically targets dissolved phosphorus, the primary nutrient fueling filamentous algae growth, thereby directly addressing the root cause of algal blooms. Phoslock is non-toxic and biodegradable, posing minimal risk to aquatic organisms and ecosystems. By reducing phosphorus levels, Phoslock helps restore water clarity, promote beneficial plant growth, and enhance overall lake aesthetics and recreational value.
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
- Lake Elsinore Fisheries Management Report
Despite these efforts, Lake Elsinore is a natural lake. 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 always high during the hot summer months.
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.
Read the latest Lake Elsinore Fisheries Management Report, published in September 2020
Read press release announcing completed Lake Elsinore Fisheries Management Report
- How often and where are lake samples collected for testing?
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During periods of “Danger” advisory levels, testing occurs on a weekly basis. When toxins are at lower levels testing occurs on a bi-weekly or monthly basis.
- Who collects the samples and conducts the testing?
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The City contracts with WSP Environment & Infrastructure for sampling. WSP prepares, packages, and overnights the samples to Greenwater Labs in Florida. Test results are usually received within 3-5 business days of the collection date. Testing is primarily for microcystin, the most common type of cyanotoxin in Lake Elsinore. Other toxins might be assessed depending on current lake conditions.
- Are boats allowed on the lake when a “Danger” advisory is in effect?
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Lake users are advised to stay out of the water and to not engage in any recreation activities when toxin levels are at a “Danger” advisory level.
- At what advisory level is it safe to swim, jet ski, ski/wakeboard, or engage in other activities that result in contact with the water?
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Lake users are advised to not contact the water at the “Danger” or “Warning” advisory levels. Swimming is allowed at the “Caution” level but water should not be ingested.
- Is it safe to eat fish caught when an advisory is posted?
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Fish caught in the lake should not be eaten when a “Danger” advisory is present. During a “Warning” or “Caution” advisory fish should be cleaned and guts thrown away and fillets should be cleaned with tap water or bottled water before cooking.
- When is it safe for pets to go in the water?
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Pets should not go into or drink the water any time an advisory of any level is posted.
- What is the City of Lake Elsinore doing to reduce toxins from algae?
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The City, partner agencies, and lake scientists are continually looking at methods and researching treatment options. In a recent study, four treatments were tested and analyzed in enclosed study areas near the Launch Pointe public beach. A final report of that study, which included chemical and microbial strategies, will be released by mid-2023. The City has also applied for a grant and federal funding to conduct a pilot study that utilizes a technology to physically remove algae from the lake with a harvesting system. Award notices for that funding should be released in July 2023.
- Is the LEAMS system operating and is it helping to reduce toxic algae blooms?
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The Lake Elsinore Aeration and Mixing System (LEAMS) is operational. However, the consensus amongst the scientific community is that the system is nearing the end of its useful life and that the system has a minimal effect on reducing toxic algae blooms. The City and Elsinore Valley Municipal Water District are continually monitoring the system and are currently exploring options for upgrading, repurposing, or replacing the system.
- Why aren’t alum, copper sulfate, or other algaecide treatments applied to Lake Elsinore?
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These treatments have been considered and researched and could possibly be part of the mix of treatments. However, it is generally agreed upon that there isn’t one treatment that will serve as a “silver bullet” to eliminate toxic algae blooms in Lake Elsinore due to the size and complexities of the lake. These treatments are considered as short-term solutions and would need to be applied regularly at a high volume and cost due to the size of the lake (3,000 acres).