The winter of 2017 was a gift in many ways. Not only did it bring desperately needed water to California and end a statewide drought emergency, it highlighted the need to build more surface water storage projects like Temperance Flat on the San Joaquin River.
California’s investment in water infrastructure has not kept up with the ever-growing demand for water supply. Many aging facilities don’t have the capacity necessary to keep up with our state’s population growth. Friant Dam and Millerton Lake are too small to capture runoff from the massive watershed above it. As a result, millions of acre-feet of water washed out to sea during the spring thaw even though California was still technically in a drought.
Building a bigger storage system to capture the San Joaquin River’s flows in wet years is only one of the many benefits of Temperance Flat. Once built, Temperance Flat will also enhance flood protection downstream.
In 1997, Friant Dam was tested when a historic storm sent floodwaters raging down the San Joaquin. Friant Dam spilled at record levels and caused millions of dollars in damage while putting lives at risk. Temperance Flat will significantly improve flood protection for the communities down river while capturing and storing the excess flows.
Users of the project, including environmental and resource interests, will be able to purchase a storage account of water and use it however and whenever it is needed.
From an environmental perspective, Temperance Flat will directly and positively impact the San Joaquin River. At its inception, Friant was the only major dam in California not designed to send the water it stores down the river channel it blocks. Instead, two holes in the dam were constructed to send water south through the Friant-Kern Canal and north to the Madera Canal for agricultural and urban uses.
Temperance Flat will nearly triple storage capacity above Friant Dam and deliver water from the San Joaquin River to farms on the west side, ensuring higher and more reliable flows, and restoring the San Joaquin River back to the levels and flows that once occurred naturally.
Another key benefit of Temperance Flat is its location. Located south of the fragile Delta ecosystem, supplies from Temperance Flat could be called upon during times of water emergencies.
The most unique aspect of the project is the water storage account system the Temperance Flat designers have created. Users of the project, including environmental and resource interests, will be able to purchase a storage account of water and use it however and whenever it is needed.
Environmental resource managers will have the flexibility to operate water in Temperance Flat and access that water in dry years in order to protect natural resources – free from political pressure or external forces.
Finally, Temperance Flat will play a key role in groundwater recharge. With California’s new Sustainable Groundwater Management Act in place, getting water back into the severely over-drafted aquifers is critical.
Water behind Temperance Flat could be delivered to Central Valley water basins, bringing water levels back to sustainable levels for the future. Restoring groundwater supplies is critically important for disadvantaged communities that have suffered undrinkable groundwater for years, a condition which has been exacerbated throughout our recent drought.
The Temperance Flat Dam project will help meet California’s urban, rural, agricultural, and environmental water needs today and for generations to come. It is time for California to invest in water infrastructure to meet the crisis of today and prepare for tomorrow.
Dr. Joaquin Arambula represents the 31st District in the Assembly. This opinion was co-authored by seven lawmakers representing Valley districts: Assemblymembers Frank Bigelow, Adam Gray, Devon Mathis, Heath Flora, Jim Patterson and Rudy Salas; and state Sen. Anthony Canella.