Driving down Raymond Avenue, over the Riverside freeway, and continuing until it became East Street in Anaheim, I noticed a large fenced in area which reminded me of a dried-up lakebed, with a brown wooden sign that closely resembled the one near the Fullerton and Brea Dams. Looking closer, I realized that this was a sign for the Raymond Basin, a flood basin owned by the Orange County Flood Control District (OCFCD), and designed for water conservation and flood control. Mild winters and long hot summers are what Southern Californians are now used to. Seldom is there any measurable rainfall from May through September. Since Southern California has received less rain than usual for this time of year, I thought it would be interesting to do further research into the Raymond Basin and the OCFCD.

Raymond Basin. Photo by Emerson Little

Built for Water Conservation

The Raymond Basin was first constructed in 1953 as a water conservation basin. By 1954, the Orange County Flood Control District had purchased the land, and in 1959, made improvements to transform it into a dual-use basin. It functions as “both a water conservation basin and a flood control retarding basin” according to information posted by the OCFCD on a fenced corner of the present-day basin. The wooden sign placed by the basin’s gates says that it was completed in 1962. Subsequent improvements to the basin, as recently as 1990, have transformed it into what we see today.

The basin is capable of storing up to 370 acre-feet of water at any given time. An acre foot of water is the approximate amount of water a family of four uses in one year’s time. Currently, the OCFCD uses the basin to assist in preventing flooding the downstream community by storing a portion of high flood flows within two sub-basins. The sub-basins are divided by a flow-by channel (Carbon Creek Channel) which runs down the middle of the facility and uses tow side-weir spillways (located near Balsam Avenue) to direct high flood flows into each sub-basin. The flood flows are stored in the basins until the depth of the water in the bypass channel recedes. Then, small pipes convey the retained water back to the channel. Any water left in the basins percolates into the groundwater aquifer below. When I walked by, the east basin had a tiny spot of mud surrounded by dry, cracked dirt, while the west basin had a large algae covered section with a shallow amount of water. Near the algae water, a small group of birds had congregated.

The OCFCD uses the basin to recharge the groundwater aquifer within the Orange County Forebay Area. Water from the Santa Ana River, the State Water Project, or the Colorado River Project may be diverted from Anaheim Lakes, or Warner and Miller Basins upstream, down Carbon Creek Channel to the Raymond Basin. It’s there that the water is stored and allowed to percolate into the earth, recharging the groundwater aquifer below. When it’s clean, the Raymond Basin can percolate up to ten feet of water a day. However, over time, between six to eight months, the bottom two or three inches of soil on the basin bed may become clogged with silt and biological material, reducing the percolation rate to almost zero. Therefore, it’s important to frequently clean the basin’s bed in order to maintain its ability to percolate water.

Raymond Basin wooden sign. Photo by Emerson Little

A History of Flooding in Orange County

Orange County has an interesting history of floods. According to A Brief History of the Orange County Flood Control District, by the American Society of Civil Engineers, before 1825, the flood outwash of the Santa Ana River meandered from the canyon across the Coastal Plain and merged with the San Gabriel River before entering the ocean at Anaheim Bay (near what is now the City of Seal Beach). As a consequence of the flood of 1825, the river mouth of the Santa Ana was diverted several miles southeasterly and what is now known as Balboa Peninsula was formed by river sedimentation. The flood of 1862 was Orange County’s largest, when the river raged out of control. According to a Los Angeles Times article from January 1995, “the destruction was not great, only because the area was so sparsely populated. In the center of Anaheim, four miles from the Santa Ana River, water stood four feet deep. The flood brought from the mountain and canyons great rafts of driftwood, which were scattered over the plain below the city and furnished fuel for the people of the city for several years.”

Flood Control Measures

Orange County was established in 1889 when the State Legislature separated it from Los Angeles County, and flooding was not new to the inhabitants of the area. Early organized attempts to control floodwaters in Orange County were primarily by agricultural groups who constructed and maintained ditches from diversion dams in the streams to irrigate their farms. Early efforts were largely focused on the Santa Ana River, and the works constructed were temporary, with most being accomplished by individuals or by localized protection districts. From 1850 to 1930, there were 15 years where major floods happened. Out of these flood years, the ones in 1862, 1884, and 1916 were the largest and the most destructive (both in terms of property damage and loss of life). It wasn’t until after the Flood of 1916 that flood protection began to receive more attention in Orange County.

According to A Brief History of the Orange County Flood Control District, “by 1927, Orange County had developed into a highly agricultural area with the subsequent amount of urban development. With the county developed to this extent, it became economically feasible to expend funds for flood protection.” On April 2, 1927, Paul Bailey, the State Engineer at the time and a prominent consulting engineer living in Orange County, filed a report with the California Governor and the State Legislature on the water problems of San Bernardino, Riverside, and Orange Counties. The consulting Engineering Committee working with Bailey at the time was J.B. Lippincott for Orange County, A.L. Sonderegger for Riverside County, and George S. Hinckley for San Bernardino County. On May 23, 1927, the Orange County Flood Control was formed and approved by the State Legislature.

Protecting Life and Property

Today, the OCFCD’s main duties include control of flood and storm waters of the county, and of streams flowing into the area, such as the Santa Ana River and San Juan Creek. Other duties include mitigating the effects of tides and waves and protecting the harbors, waterways, public highways and other properties in the county from these waters. The facilities constructed by the Orange County Flood Control District, such as the Raymond Basin, have prevented a great deal of losses to life and property that would have otherwise been harmed by flooding. By constructing flood control facilities at the same time as new development, the OCFCD has made residential and commercial developments in the county more secure from flooding.

To view my video about the Raymond Basin click HERE.