Drinking Water: Groundwater Availability, Challenges and Solutions

In Southern California, groundwater plays a major role in providing a sustainable drinking water source for millions of people. The percentage of tap water that a person receives from groundwater supplies varies throughout the Southern California region. Some homes receive 100 percent of water from a groundwater source, while others get a blend of both local groundwater and imported water from Northern California, the Colorado River or a blend. Curious where your water comes from? Check your water agency’s consumer confidence (water quality) report to find out the specific source of the water that gets delivered to your home.

In 2014, the state of California passed the Sustainable Groundwater Management Act to mandate the management of groundwater basins throughout the state. Southern California groundwater basins are managed to ensure that water supplies are appropriately monitored. While in Southern California the basins have been managed for years prior, it was not until 2014 that central and Northern California were also required to follow suit and manage their groundwater basins. Because of the Act, all groundwater basins in California are now required to be managed, however there are still complexities associated with groundwater management.

Lake Drying Up

“The challenge in managing groundwater supplies is that the state doesn’t know exactly how much groundwater we have available, how much is used and this poses a potential for over drafting of the groundwater basins,” shares Dr. Behrooz Mortazavi, P.E., principal at Water Resources Engineers, Inc. and advisor to the Hemet – San Jacinto Watermaster.

The Chino Basin, one of Southern California’s largest can hold roughly 5,000,000 acre-feet of water. One acre-foot of water is enough to fill a football field with one foot of water in depth. Located in the Santa Ana Watershed, the basin is located in parts of Los Angeles, Riverside and San Bernardino Counties. Our area is also home to the Santa Margarita River Watershed, San Bernardino Basin, Cucamonga Basin and the Warren Valley Basin.

“Groundwater has been used to support life in the Chino Basin since the early days of settlement, and was the major supply supporting the booming agriculture industry throughout the 20th century,” states Peter Kavounas, P.E., general manager for the Chino Basin Watermaster. “As the region continues to grow, the paving of land surface for roads, homes and industry, will continue to diminish the amount of recharge to all groundwater basins.”

California groundwater basins are primarily managed by what is known as a, “watermaster.” The watermaster is responsible for ensuring that water is correctly allocated based on rights determined by judicial rulings. The Hemet-San Jacinto Watermaster is made up of four representatives from municipal water agencies and one from a private organization. According to the California Department of Water Resources, the Watermaster program assigns an unbiased, qualified person to determine water allocations, thereby reducing water rights court litigation, civil lawsuits, and law enforcement workload. It also helps prevent the waste or unreasonable use of water. The watermaster is not responsible for water quality, but solely for the availability and management of the allocation, however California’s monitoring and management of water quality is of high priority. However, stricter regulatory limits the access and availability to groundwater.

Filling up a glass with drinking water from kitchen tap

Along the Santa Ana River, public water agencies, as well as joint powers authorities, such as the Santa Ana Watershed Project Authority (SAWPA), develop projects to increase groundwater availability. The Inland Empire Brine Line is an example of a project that protects the quality of groundwater basins in the Inland Empire and Orange County. The Brine Line is able to remove salts from the wastewater of manufacturing facilities, as well as other processes. Removing salt from the wastewater discharge protects wildlife and water that percolates into local groundwater basins.

As California’s drought continues, groundwater supplies will continue to diminish. Protecting local groundwater will rely heavily on seeking solutions to store, treat and reuse existing supplies. Public water agencies within the boundaries of the Santa Ana River Watershed have already made strides in creating water supplies through groundwater desalination and the reuse of recycled. The critical step to securing groundwater availability in times or little snow and rainfall will be to maximize existing supplies by through treatment and reuse.