Notice of Preparation of Environmental Impact Report (EIR). Public comment period ends July 2, 2007

Perris Dam Project Overview

The Department of Water Resources (DWR) has identified potential seismic safety risks in a section of the foundation of Perris Dam. There is no imminent threat to life or property. However, in the interest of ensuring the maximum public safety for those using and living downstream of the lake, the state has taken precautions such as lowering the lake’s water level.

Following an independent expert analysis, DWR is moving ahead with its plans to repair Perris Dam. The independent consulting board released its findings to DWR, owner of the dam, the Division of Safety and Dams, which regulates the safety and integrity of California dams, and the Metropolitan Water District of Southern California (MWD), the principal user of water from Lake Perris.

DWR has thoroughly evaluated the best and most feasible repair options to address the seismic concerns at Perris Dam. The finalized repair plan includes upgrading the dam by replacing the foundation material and reinforcing it with a stability berm placed on top of the improved foundation. This will allow the lake to return to its previous maximum operating pool elevation after construction. Other aspects of the repair plan include constructing a new outlet tower and emergency outlet release facility.

Construction is estimated to begin in the fall of 2008. Dam completion is expected by fall 2010. All projects concerning the Perris Dam are anticipated to be complete by fall 2012.

Lake Perris is located in northern Riverside County, and is the southernmost State Water Project Facility and the southern terminus of the East Branch of the California aqueduct. The Lake Perris State Recreation Area is one of the state’s most popular recreation destinations, with an average attendance of 1.1 million visitors.

If you have comments, questions, or would like to receive current updates regarding the Perris Dam remediation project please contact DWR at perrisdam@water.ca.gov.