Like a savings account, water banking provides the Southern Nevada Water Authority (SNWA) the ability to store water for the future. Through various programs and agreements, the Water Authority "banks" water as a reserve supply.
Banked water resources are key to meeting water demands during a shortage and providing interim supplies while other resources are being developed. The Water Authority has banked more than 1.8 million acre-feet for future use—the equivalent of eight years' worth of water resources—across three water banking projects in Arizona, California, the Southern Nevada Water Bank, and Lake Mead (in the form of Intentionally Created Surplus).
Arizona Water Bank
The SNWA has stored approximately 601,000 acre-feet of Colorado River water underground in Arizona's aquifers for our future use.
For the Water Authority to recover this water, Arizona will utilize the banked water and forgo use of a like amount of Colorado River water from Lake Mead. The Water Authority will then divert the water from facilities at Lake Mead. SNWA can recover up to 40,000 acre-feet per year during any supply condition and may recover up to 60,000 acre-feet per year during a declared shortage.
California Water Bank
Between 2004 and 2012, the SNWA entered into various agreements that allow it to store Nevada's unused Colorado River water in California. As of 2017, Nevada has banked more than 330,000 acre-feet of water in California and can recover up to 30,000 acre-feet per year during normal and shortage conditions, subject to agreement terms.
Southern Nevada Water Bank
Beginning in 1987, the Las Vegas Valley Water District and later the City of North Las Vegas — both Southern Nevada Water Authority member agencies — began pumping treated Colorado River water into the valley's primary groundwater aquifer in years when Nevada's Colorado River allocation exceeded demand.
As of 2017, the Water Authority has accumulated approximately 336,000 acre-feet of water stored in the Las Vegas Valley aquifer for future use through an agreement with the Las Vegas Valley Water District.
The Water Authority may recover up to 20,000 acre-feet per year under this agreement in any water supply condition.
If not used in the year created, Intentionally Created Surplus credits are stored in Lake Mead and can be used in the future, subject to contract and system conditions.
As of the end of 2017, the Water Authority has approximately 582,000 acre feet stored in Lake Mead.