Public Notice Announcement – Canyon Lake Alum Application, October 11-15, 2021

Lake Elsinore & San Jacinto Watersheds Authority (LESJWA), is informing the Canyon Lake community that doses of alum will be applied to the lake in the main body, east bay and the area north of the causeway from October 11-15, 2021. Alum binds with phosphorus in the lake water, drops the nutrient to the lake bottom and thereby reduces algae growth in the lake.  Canyon Lake water mostly comes from stormwater runoff from the upper watershed each year that has  high levels of nutrients that hurt water quality and threaten aquatic life. This dose will be the 16th Canyon Lake alum application that has taken place.

Alum, the method selected to provide the best results for Canyon Lake, has a proven track record of success and is safe to both humans and aquatic life. Drinking water quality will not be affected by any of the treatment options. Canyon Lake will remain open during the entire treatment process. Recreational users will experience little disruption during treatment application and implementation.

In order to comply with water quality regulations enforced by the State, through the local Santa Ana Regional Water Quality Control Board, the Lake Elsinore & Canyon Lake Nutrient Total Maximum Daily Load (TMDL) Task Force, a coalition of cities, the county and several other organizations led by LESJWA, provides  funding to continue alum water treatments in Canyon Lake. The TMDL Task Force evaluated several options during the CEQA process and determined that alum application provides the best option as a step to effectively treat the entire lake in a timely manner with minimal impact to Canyon Lake residents.

Alum Schedule (subject to change)

Additional Information

Mark Norton
Lake Elsinore & San Jacinto Watershed Authority
Tel: 951-354-4221
Email: MNorton@sawpa.org