Santa Ana River Basin - Riverside Levees Rehabilitation Project
Project Description
This U.S. Army Corps of Engineers (USACE) led Santa Ana River Basin- Riverside Levees Rehabilitation Project will rehabilitate damaged portions of the Federally constructed Riverside Levee 1 (West levee) and Riverside Levee 2 (East levee), collectively the "Riverside Levees," which are part of the Santa Ana River levee system. Approximately 9,000 feet of the West levee will be rehabilitated starting from Market Street and continue southwesterly downstream to just past Capary Road. Approximately 4,000 feet of the East levee will be rehabilitated starting from the County line and continue southwesterly downstream to approximately Columbia Avenue. This project also includes a short reach of the East levee between Market Street and State Route 60. Levee rehabilitation will include replacing and grouting the existing levee rock slope protection, as well as extending the rock slope protection (see Exhibits 1 & 2 below)
Exhibit 1 – Riverside Levees Exhibit
Exhibit 2 – Levee Cross Section
Project Purpose, Need and Benefits
The purpose of the Santa Ana River levee system is to reduce the potential for Santa Ana River flows to break out of the channel and flood adjacent properties. The levees range from 15 ft. to 22 ft. in height above the elevation of the riverbed. The levees were originally designed in the 1950’s to convey a flow of approximately 195,000 cubic ft. per second (cfs), well in excess of the estimated 100- year flow of 140,000 cfs.
A series of storms from December 2010 to January 2011 resulted in substantial flows in the Santa Ana River and damaged portions of the Santa Ana River levee system. Inspections performed by the Riverside County Flood Control and Water Conservation District and USACE in June 2011 identified damages to the Riverside Levees, including intermittent erosion at the toe of the riverward slope and the erosion of several groins on both banks of the river. Most of the damage was to the groins, which act as rock brake pads to slow the flow of water near the levee.
The rehabilitation of Riverside Levees is authorized by Public Law 84-99. Public Law 84-99 authorizes USACE to assist local governments with the rehabilitation of Federal and non-Federal flood risk management projects damaged by flooding.
The Riverside Levees rehabilitation project will not only restore but enhance the levees to ensure they continue to protect approximately $1.5 billion of infrastructure. The project will ensure flood protection for more than 4,300 structures, of which more than 4,000 are residential structures in the Riverside and Jurupa Valley areas. A summary of the structures being protected by Santa Ana River levee system is provided in Table 1 and Figure 1 below. In addition to protecting property, the rehabilitation project will provide additional scour protection and integrity to the Riverside Levees.
Figure 1: Location of Structures being protected by the Riverside Levees Project
Table 1: Summary of Structures protected by the Riverside Levees Project
Project Status and Outreach to Those Experiencing Homelessness Within the Santa Ana River Construction Area