Canyon Lake to receive 19th dose of alum

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 April 10 through April 14. Alum binds with phosphorus in the lake water, drops the nutrient to the lake bottom, and thereby reduces algae growth in the lake.

The lake will remain open during the entire treatment process. Recreational users will experience little disruption during treatment application and implementation.

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 19th Canyon Lake alum application that has taken place.

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.

The treatment schedule is as follows (subject to change):

  • Monday, April 10: Main body from 7 a.m. to 4 p.m. p.m.
  • Tuesday, April 11: Main body from 7 a.m. to 4 p.m. 
  • Wednesday, April 12: Main boat ramp to the west end of East Bay from 7 a.m. to 4 p.m. 
  • Thursday, April 13: East Bay from 7 a.m. to 4 p.m.
  • Friday, April 14: North ski area and clean up from 7 a.m. to 4 p.m.

For more information, contact Mark Norton at Lake Elsinore & San Jacinto Watershed Authority at 951-354-4221 or [email protected]. For daily operation updates, visit


Social Media

Explore More


Get The Latest Updates

Subscribe To Our Weekly Newsletter

No spam, notifications only about local news stories. 

On Key

Related Posts