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Remediation Projects

Perris Lake

Outlet Tower Improvements

DWR completed a seismic stability analysis of the outlet tower located at the southeast corner of the lake and determined the tower itself is stable; however improvements to the access bridge seats and tower controls are needed. The effort to implement the Outlet Tower Improvements will occur in three separate contracts with all work currently scheduled for completion in 2021:

  • Design and construct a retrofit to the outlet tower bridge seats to meet the current seismic requirements. Design is approximately 60% complete and construction is scheduled to commence by mid-2018 and complete in late 2019.
  • Design and procure a second reservoir emergency outlet control slide gate and new control equipment. Design initiated in July 2017 and the estimated equipment delivery date is August 2020.
  • Design and construct modifications to the existing emergency outlet control structure to house the new slide gate and the new control equipment. In addition, DWR will refurbish the existing slide gate, procure and install new standby engine generator, replace the existing flow measuring equipment, and relining of a portion of the outlet piping. This work is currently scheduled to start in January 2018 and complete by mid-2021.

Emergency Release Facility

A standard feature of all regulated dams is a means to empty the reservoir in a controlled manner. This feature would only be activated if there was ever a threat of an imminent dam failure. The emergency outlet control structure is located near the southeast end of the dam.

Due to the slope of the land, the current emergency outlet directs water to the southwest and across the Ramona Expressway. From this direction the water naturally flows toward the Perris Valley Channel, a flood control facility operated and maintained by the Riverside County Flood Control and Water Conservation District. This flow direction would pose a risk to the residential homes that are now standing on the farmland that was located southwest of the dam when the dam was first constructed.

The proposed Emergency Release Facility Project (ERF) would reduce the damage that would be caused to life and property resulting from an emergency release by directing the water northwest through a system of levees and channels. That system is designed to run parallel to the Ramona Expressway and send water directly into the Perris Valley Channel.

Draft Environmental Impact Report

An Emergency Release Facility Draft Environmental Impact Report (DEIR) was released between September and October 2016. Subsequent to the public review period in late 2016, DWR initiated an effort to amend the DEIR to clarify issues raised during the public comment period. The amended DEIR is anticipated to recirculate in September 2017.

A printed copy of the DEIR will also be made available at the Office of Planning and Research, Riverside County Library, Perris Branch (163 E. San Jacinto Ave., Perris, CA 92570), and Moreno Valley Public Library (25480 Alessandro Blvd., Moreno Valley, CA 92553). A copy of the DEIR will be posted to DWR’s Perris Dam Remediation Program page when it is available.

Once released, comments to the recirculated DEIR can be submitted to Tom Barnes.

Preliminary Design of the ERF was suspended in early 2017 due to the redirection of design resources following the spillway incident at Lake Oroville. Final design will resume in 2018 with construction anticipated to occur between 2020 and 2022.