The Santa Ana River Interceptor (SARI) Line is a 23-mile-long wastewater pipeline that extends from the Orange/San Bernardino County boundary just southwest of Prado Dam to the Orange County Sanitation District (OCSD) sewage treatment plant in Fountain Valley. The SARI Line serves the sewage disposal needs of Yorba Linda, east Anaheim, Orange, and portions of Garden Grove, Santa Ana and Fountain Valley. It also serves segments of Riverside and San Bernardino counties by conveying raw sewage and brine (wastewater from agriculture, commercial, industrial and other sources) to OCSD's treatment plant.
Several segments of the SARI Line lie under the Santa Ana River within Santa Ana Canyon between the Orange/San Bernardino county boundary and Weir Canyon Road. Constructed in the mid-1970s, the SARI Line was originally buried about 20 feet below the river bed. Over time, the amount of soil covering the SARI Line has eroded, leaving the pipeline virtually exposed in some locations. This condition puts nearly 4 miles of the SARI Line in jeopardy of failure during heavy rainstorms when high volumes of storm flows are released from Prado Dam. In addition, the U.S. Army Corps of Engineers has raised the level of Prado Dam by 30 feet, and has increased the discharge capacity into the Santa Ana River from 10,000 cubic feet per second to 30,000 cubic feet per second. (A cubic foot is approximately the size of the box containing a regulation-size basketball.)
As an interim measure until the SARI Line can be permanently relocated, OCSD constructed several grade stabilizers to protect the existing pipeline. However, to ensure the long-term integrity of the pipeline, protect public health and safeguard the environment, the Orange County Flood Control District, in cooperation with the Orange County Sanitation District and the Santa Ana Watershed Project Authority, is now embarking on the Santa Ana River Interceptor Relocation Project. This project will relocate and replace the SARI Mainline with a new 54-inch-diameter pipeline on the south side of the river just north of the Riverside (91) Freeway. A new 15-inch-diameter gravity sewer will be constructed along La Palma Avenue and Santa Ana River Trail to capture flows from the north side of the river. These new locations will protect the pipeline from stormwater flows in the river.