Roseville injects surface water underground

Updated February 20, 2019
Roseville injects surface water underground
Thanks to Mother Nature this winter, we’ve seen near-record rainfall and a healthy snow pack. Because of significant surface water availability, we're exercising investments made more than 10 years ago by injecting available water supplies beneath the ground using surplus surface water resources through our contract with the Bureau of Reclamation Central Valley Project.

Through March 1, Roseville will work towards injecting up to 25 acre-feet of water, which is equivalent to about 8.1 million gallons of Folsom Lake water—enough to supply 56 homes for the entire year. This will allow us to test real-world injection capacity at two newer wells.

Because Folsom Reservoir serves both as a flood protection and water supply facility, operators of the reservoir release water to make room for additional rain and snow melt. Released flood water flows ultimately to the Pacific Ocean given the vast amounts of water in a short time period. With our groundwater program, we have the ability to take flood control releases from Folsom Reservoir and bank it locally in Roseville.

Known as Aquifer Storage and Recovery, we have a constellation of six groundwater wells that allow us to prepare for the future by banking water during times of plenty and extracting water when we need it. The groundwater basin acts much like a surface water reservoir. Water is stored within the pore spaces between underground sediments.

Serving as a water savings account, Roseville is literally banking and saving water underground and can use it when we need it or to further stabilize our groundwater basin, which is a key component of the Sustainable Groundwater Management Act.

Although the amount of water is small during this period, it allows us to test our wells and the groundwater system so that we are poised and ready to inject more water overtime.  In fact, we estimate that there is space equal to the volume of Folsom Lake underneath the ground available to receive this water. 

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