Protecting water quality and supply through vegetation management
The Orange County Water District (OCWD) owns approximately 1,500 acres of land in Anaheim and Orange, including a six-mile stretch of the Santa Ana River. 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. These activities help sustain the Orange County Groundwater Basin, which supplies about 85% of the drinking water for 2.5 million people in north and central Orange County.
How Vegetation is Managed
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. Removing this 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.
During this work, 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. Areas managed by OCWD are left undisturbed if birds are nesting. Sediment and vegetation work is generally completed before or after nesting activity is observed, allowing the land to support both groundwater recharge and wildlife.
OCWD does not spray herbicides in Orange County waterways, on their banks, or at the top of the slope bounding the waterway
Herbicides are used when needed and are applied directly onto weeds in landscaped areas, along fence lines, roadsides, and dirt or paved areas.
OCWD uses glyphosate in limited, targeted applications upstream of Prado Dam to control the spread of Arundo donax, a highly invasive, water-intensive, and extremely flammable plant that crowds out native vegetation and destroys the habitat of threatened and endangered species. It is used on Arundo that has emerged following mechanical removal. Glyphosate is absorbed into the plant and kills the root; then quickly binds to soil and is broken down by naturally occurring microbes. Glyphosate is the most effective and least disruptive method currently available to achieve long-term control while minimizing disturbance to surrounding habitat.
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 and label directions permitted by the California Department of Pesticide Regulation.
Protecting Your Water Supply
California maintains some of strictest drinking water standards in the nation. The California State Water Resources Control Board’s Division of Drinking Water regulates 14 herbicides, including glyphosate. OCWD performs water quality monitoring for more than 30 herbicides, including glyphosate. Water quality testing confirms that all sample results comply with applicable state and federal standards. Furthermore, all tests from drinking water wells have been non-detect for glyphosate.
OCWD collects water samples from approximately 1,500 locations throughout the Orange County Groundwater Basin and tests for more than 500 compounds – far more than what is required by state and federal agencies.
Residents may review their local water provider’s annual Consumer Confidence Report for detailed information about drinking water quality, testing results and compliance with state and federal standards.