Get the facts about OCWD
Misinformation has been circulating regarding the Orange County Water District (OCWD) activities in and around the Santa Ana River, which serves as both a flood control channel and a source of groundwater replenishment. Here are the facts.
The Orange County Water District is conducting approved maintenance within and adjacent to the Santa Ana River. Before work began, OCWD notified the California Department of Fish and Wildlife, which acknowledged receipt and approved the work to proceed.
OCWD biologists conducted multiple surveys before maintenance began, and no active bird nests were identified. Biologists are also continuing to monitor the work areas in person while maintenance is underway.
The maintenance includes removing non-native vegetation while retaining native vegetation. Crews are currently working along the river, with additional maintenance planned over approximately the next three months.
This work is being completed in preparation for the upcoming rain season and supports OCWD’s ongoing efforts to safely manage river flows and maximize the capture of Santa Ana River water into the groundwater basin, an important local source of drinking water for Orange County. This preparation is particularly important as Southern California enters the rain season amid a strengthening El Niño.
The Orange County Water District owns approximately 1,500 acres of land in Anaheim and Orange. Within these lands, OCWD manages vegetation to support groundwater recharge and carries out environmental preservation efforts that protect and maintain habitat for native plants and wildlife. Mechanical and hand removal are OCWD’s preferred vegetation management methods, including the use of heavy equipment such as bulldozers. This equipment is used mainly to remove material that builds up over time, blocks the ground’s surface, and prevents water from soaking into the groundwater basin.
OCWD uses low-ground-pressure bulldozers equipped with wide tracks that distribute the equipment’s weight over a larger surface area, helping minimize ground pressure and reduce the potential for soil compaction.
Removing accumulated material, along with some vegetation, is part of the ongoing maintenance needed to keep water moving through the recharge facilities and replenishing the groundwater supply. Research has documented how maintenance and the removal of accumulated material in river channels can improve water infiltration rates.
During maintenance activities, OCWD takes steps to protect habitat, wildlife, and water quality. These measures include biological surveys, oversight by qualified biologists, and regular equipment inspections and maintenance to prevent leaks or discharges.
Research articles about sediment removal improving percolation:
- Maximizing infiltration rates by removing suspended solids: results of demonstration testing of riverbed filtration in Orange County, California
- Clogging behaviour and management in two full-scale infiltration schemes: A treated wastewater basin and a surface-water weir in Australia
- Application of physical clogging models to Managed Aquifer Recharge: a review of modelling approaches from engineering fields
- Artificial recharge of groundwater: hydrogeology and engineering
- Assessment of clogging of managed aquifer recharge in a semi-arid region
When OCWD equipment moves through the Santa Ana River during routine maintenance, it can stir up insects, fish and other food. Birds such as egrets and herons often follow closely to take advantage of these newly available food sources.
Similar behavior has been documented around the world, where birds follow agricultural equipment, lawnmowers and other machinery to find insects and other food uncovered along the way.
OCWD has been a good steward of the Santa Ana River Watershed and the environment it supports for decades. The District implements programs and projects to protect the habitat, endangered species and the river water itself, and employs four full-time biologists to oversee its operations. These efforts include bringing an endangered bird, the least Bell’s vireo, back from the brink of extinction and helping the vireo to flourish within the Santa Ana River Watershed, restoring habitat for the Santa Ana sucker fish, and creating nesting areas for other endangered, threatened and sensitive bird species.
The Santa Ana River is a critical part of Orange County’s flood-control system. For many decades, the river has been dammed, channelized, and modified to reduce flood risk and protect life and property in a highly developed area. Before these flood-control facilities were built, Orange County experienced major floods that caused loss of life and significant property damage. Today, the U.S. Army Corps of Engineers and the County of Orange work closely to manage and maintain river facilities that help reduce flood risk and protect surrounding communities.
Between Weir Canyon Road and Riverview Golf Course, the Santa Ana River is an engineered flood-control channel with an earthen bottom, rock-protected banks and structures designed to stabilize the riverbed and convey floodwaters. River flows can vary significantly, from about 600 gallons per second during lower-flow periods to approximately 37,000 gallons per second or more during higher-flow conditions, depending on storm conditions and releases from Prado Dam.
Vegetation and sediment can reduce the amount of water the channel can safely carry by obstructing flows, accumulating in the channel, or redirecting water toward banks and levees. The U.S. Army Corps of Engineers’ Lower Santa Ana River Operation, Maintenance, Repair, Replacement, and Rehabilitation Manual directs that channels be kept clear of “debris, weeds, and wild growth.” Its inspection guidance also identifies vegetation that impairs flow capacity, and sediment deposits stabilized by vegetation that reduce capacity or redirect flows, as conditions requiring maintenance.
OCWD does not spray herbicides, including glyphosate (the active ingredient found in some Roundup products), in Orange County waterways, on their banks, or at the top of the slope bounding the waterway. Herbicides used for District operations are sprayed directly onto active weeds within landscaped areas and weeds growing along fence lines, sides of roads, and dirt areas. Vegetation management is crucial for OCWD to maintain water supply, maximize groundwater recharge, prevent catastrophic wildfires, maintain flood control infrastructure, and protect endangered species habitats. Glyphosate-containing herbicides are available to the public over the counter and are used in residential, commercial, agricultural, and other settings.
OCWD uses glyphosate in areas behind Prado Dam in Corona to kill Arundo donax, a highly invasive and water-guzzling plant that crowds out native vegetation and destroys the habitat of threatened and endangered species. Removing Arundo allows native plants and animals to flourish. Management of Arundo and other invasive vegetation is required under permits and agreements with the U.S. Fish and Wildlife Service, the U.S. Army Corps of Engineers, and the California Department of Fish and Wildlife. Glyphosate is always applied in accordance with all applicable state and federal regulations.
Learn more about how OCWD’s manages vegetation to protect water supply.
In consultation with the Division of Drinking Water at the State Water Resources Control Board, OCWD has collected and analyzed more than 1,800 water samples for glyphosate from drinking water wells throughout the Orange County Groundwater Basin since 1990, and they have all been non-detect for glyphosate.
In addition, OCWD maintains a water quality monitoring program around the Santa Ana River. Monitoring wells in this program have been tested for over 30 years, and all water samples taken by OCWD have been non-detect for glyphosate.
On a quarterly basis, OCWD tests Santa Ana River water for glyphosate. From over 230 river water samples collected over the past 30 years, only one sample collected in 2016 showed any detection of glyphosate. This detection was well below the Environmental Protection Agency regulatory limit or Maximum Contaminant Level (MCL) for drinking water. For reference, the current State and Federal MCL for glyphosate is 0.7 parts per million.
OCWD monitors groundwater from approximately 1,500 locations collecting around 9,000 groundwater samples annually, and testing for more than 500 compounds – far more than what is required by state and federal agencies. Water pumped from the Orange County Groundwater Basin meets all state and federal drinking water standards. Additionally, OCWD provides water quality data to its 19 cities and retail water agencies who produce an annual Consumer Confidence Report (CCR) that details the results of the extensive water quality tests done by OCWD on groundwater wells and the water distribution system.
Learn more about OCWD’s water quality programs and practices.
OCWD manages a six-mile stretch of the Santa Ana River and operates in an additional 2.5-mile stretch owned by the Orange County Flood Control District.
OCWD fills the Orange County Groundwater Basin using a variety of sources, including highly purified recycled water, Santa Ana River water, rainfall, and imported water. On average, Santa Ana River water provides about 45% of OCWD’s annual groundwater recharge. If less stormwater is captured for recharge, that water supply would need to be replaced with purchased water, which is more costly and requires more energy to transport, increasing the associated carbon footprint.
More than two dozen recharge facilities operated by OCWD receive water, which is naturally filtered as it percolates into the basin’s aquifers. OCWD’s long history of active management and investment in the local groundwater basin has not only sustained the basin but tripled its annual yield while providing high-quality water for much of central and northern Orange County.
OCWD is a separate entity from the County of Orange. The District is governed by the Orange County Water District Act created by the California State Legislature via Senate Bill 1201 which was signed into law on June 14, 1933. OCWD’s District Act guides the policy decisions made by the District’s 10-member Board of Directors and informs OCWD’s day-to-day operations. Groundwater quality is a key component of OCWD’s District Act, and OCWD takes numerous actions throughout the Orange County Groundwater Basin to improve water quality.
OCWD’s District Act allows the District to construct, operate and maintain machinery, facilities, property and water resources needed to replenish the Orange County Groundwater Basin, protect water quality and support the region’s water supply.
OCWD is a not-for-profit public agency that provides water on a wholesale basis to 19 retail water agencies. They depend on the District to manage and protect the basin so they can pump groundwater to serve their customers. This helps reduce the need for retail water agencies to purchase more expensive imported water, supporting a more affordable water supply for Orange County.
District operations have oversight from many local, state and federal regulatory agencies such as: California Department of Fish and Wildlife, U.S. Fish and Wildlife Service, U.S. Environmental Protection Agency, Santa Ana Regional Water Quality Control Board, California State Water Resources Control Board, and Department of Toxic Substances Control. OCWD’s actions in the Santa Ana River are carefully coordinated with these agencies.
Learn more about the mission of OCWD.
Learn more about OCWD’s board of directors and service area.
For more than 90 years, the Orange County Water District has invested in groundwater recharge, water recycling, water quality, stormwater capture, and infrastructure. Today, OCWD manages approximately $2 billion in operational assets that support the reliability of the Orange County Groundwater Basin.
OCWD uses T- and L-shaped levees, inflatable rubber dams and valves to direct river water across the riverbed and into recharge facilities, helping increase groundwater recharge. The levees also provide nesting and roosting habitat for numerous types of waterfowl.
OCWD employs operational monitoring and security measures intended to protect its facilities, systems, infrastructure, and water supply. Ongoing maintenance, technology upgrades, security monitoring, and emergency preparedness support OCWD’s ability to identify and respond to operational risks and emerging threats while serving 2.5 million people.
The Orange County Water District works closely with the California Department of Fish and Wildlife (CDFW) as part of its ongoing regulatory coordination regarding activities within the Santa Ana River. That coordination has continued following CDFW’s Notice of Violation, with OCWD and CDFW meeting on multiple occasions to discuss the matter and exchange relevant information.
OCWD continues to notify and coordinate with CDFW regarding work in the river and is also continuing discussions with the agency regarding the existing permit and its application to ongoing activities. OCWD values its longstanding working relationship with CDFW and remains committed to meeting its regulatory obligations through a constructive and transparent process.