Water is a precious resource in Arizona, making it crucial to have a diverse water resource mix. This diversity provides flexibility in delivering water to customers, shareholders and municipalities.
SRP’s water portfolio
Our water portfolio consists of surface water stored in reservoirs and underground recharge facilities as well as groundwater pumped from wells, all of which contribute to a more secure water future for the Valley.
Wells
There are more than 270 wells in SRP’s system. We regularly adjust water pumping based on lake levels to maintain a proper balance among our water storage systems.
Groundwater recharge
Another contributor to our water resource mix is groundwater from two underground storage facilities, the Granite Reef Underground Storage Project (GRUSP) and the New River-Agua Fria River Underground Storage Project (NAUSP).
These storage sites store the water in an aquifer, a porous layer of underground rock that can hold and release water when it’s needed. During wet years, extra water is stored underground and acts as somewhat of a “savings account.” During dry years, SRP can withdraw this stored water and continue to meet water needs.
Fun fact: Combined, our underground storage facilities can recharge nearly 20 billion gallons per year.
Surface water in reservoirs
Surface water stored in our reservoirs is our primary source of water and also happens to be our most renewable method of water storage. Water from the Salt and Verde rivers, as well as from East Clear Creek, flows over our watershed, making its way to our seven reservoirs. Together, these reservoirs can hold up to nearly 750 billion gallons of water.
One of the most vital reservoirs in our system is Theodore Roosevelt Lake. This reservoir alone can hold 1.6 million acre-feet of water, making it responsible for delivering over half of the Valley’s yearly water supply.
Water releases and runoff
To manage reservoir capacity and maintain dam safety, we occasionally release water from our reservoirs. Our reservoirs may reach capacity after a winter with heavy snow that melts quickly during a warmer rainstorm or when temperatures rise in the spring. During a water release, dam operators at the reservoir open gates and valves, which allow the water to flow down the river channel. Depending on the quantity released, these water releases can result in temporary road closures where roadways enter washes. In instances of heavy water releases on the Salt River from Roosevelt, the water flow produces renewable hydropower 24/7, which is called run-of-river generation.
In advance of water releases, SRP works with municipality partners to promote safety in areas that will be affected. There is an established notification procedure in place to provide information to local government entities, emergency managers and other agencies to ensure public safety at all levels of a water release.