Proposed Changes to Water Quality Targets for Lake Elsinore

Post Date:05/01/2019 2:21 PM

Since 2004, Lake Elsinore has been deemed an impaired waterbody by the California State Water Resource Control Board. The impairment or Lake Elsinore and Canyon Lake is due, in part, to excessive algae growth caused by excessive concentrations of nutrients. The Federal Clean Water Act Section 303(d) requires that States must identify waters that do not meet water quality standards and develop a Total Maximum Daily Load (TMDL) to address the pollutants causing impairment. In 2004, the Santa Ana Regional Water Quality Control Board adopted TMDLs (2004 TMDLs) for nutrients in the Lakes that established Numeric Targets for nutrients and algae in both Lakes, Load Allocations for sources of nutrients discharged to the Lakes and an Implementation Plan.

In the case of Lake Elsinore, the key pollutants or nutrients are phosphorus and nitrogen. These nutrients encourage and lead to excessive algae growth, which contributes to poor water quality, low dissolved oxygen levels and, ultimately, fish die offs. These excessive nutrients are typically introduced into the Lake through many different avenues, such as runoff from streets, vacant land, and homes. To address these concerns, TMDLs establish a maximum level of pollutants in which the State, City and entire watershed must follow in order to meet water quality standards.

On Friday, May 3rd, the California Santa Ana Regional Water Quality Control Board will host a public workshop to accept public comments and to consider amendments to the Basin Plan to incorporate revised TMDLs for nutrients in Lake Elsinore and Canyon Lake. The TMDL Technical Document is a regulatory document that our city and the cities upstream must follow.

There have been significant improvements in the water quality in both Lakes due to the implementation of nutrient load reduction and sediment nutrient flux reduction projects, by watershed stakeholders, since the adoption of the 2004 TMDLs. However, additional nutrient load reductions are needed to ensure the beneficial uses of the Lakes are protected and excessive nutrient and algae concentrations are further reduced.

Therefore, since December 2015, the Lake Elsinore and Canyon Lake Task Force began developing the Total Maximum Daily Load (TMDL) Technical Document to support the revision of the 2004-adopted LECL Nutrient TMDLs.  The Regional Water Quality Control Board is in the midst of its formal process of peer reviewing the TMDLs through scientific research and public hearings. Thus, public participation is important and we would appreciate our residents to voice their opinions or concerns and provide testimonies that will further add to this discussion. Written and oral testimonies will be accepted and should be submitted to Ken Thesien at

Public Scoping Workshop: 

Friday, May 3, 2019 at 9 a.m.

City of Loma Linda Council Chambers

25541 Barton Street

Loma Linda, CA

A live webcast of the meeting will be available to view online:

More Information:  

Notice of Public Workshop:

All Nutrient TMDL drafts and revisions:

Lake Elsinore & San Jacinto Watersheds Authority 

Press Release: Nutrient Revision to Total Maximum Daily Loads 

View TMDL Technical Report: Revision to the Lake Elsinore and Canyon Lake Nutrient TMDLs



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