Roseville replenishes groundwater basin this fall and winter

Updated February 11, 2020
Roseville replenishes groundwater basin this fall and winter

Last November, both Roseville and the Sacramento Municipal Utility District (SMUD) entered into an agreement to transfer up to 6,000 acre-feet of SMUD water annually for three years. This agreement is a testament to our mutual commitment of  ensuring that regional water supplies are effectively and collaboratively managed within the local groundwater basin.

Roseville began replenishing the groundwater basin this past December, thanks to Mother Nature’s work on bringing in rain and snowfall, and will continue to do so through this month.

What is 6,000 acre-feet of water?

Roseville will replenish the basin up to 6,000 acre-feet. This equates to nearly two billion gallons of water annually, which is:

  • 40,000,000 bathtubs of water
  • 91 Bellagio Fountains
  • Water for about 20,000 households

What determines if Roseville can transfer water for groundwater replenishment?

The transfer of this water, allowed under the federal Central Valley Project Improvement Act, will be put to beneficial use using Roseville’s Aquifer Storage and Recovery program to replenish the groundwater basin and store water for later. This water transfer is contingent on various factors that will be protect against current water supply and environmental agreements:

  • Transfers can only occur during seasonal high flow periods during the months of December through February, and following critical temperature compliance season for Chinook salmon spawning in the fall.

  • The U.S. Bureau of Reclamation, operator of Folsom Dam, has ultimate decision-making power of the water transfer.

  • The actual amount of water that will be recharged is limited by the capacity of current Roseville groundwater infrastructure. Based on these infrastructure limitations, we estimate that we can recharge less than 2,000 acre-feet into the groundwater basin underlying Roseville in the first year.

 Benefits of SMUD transfer water

  • The water stays local, which allows Roseville to bank the water using its network of replenishment wells. This surface water supply will supplement groundwater resources.

  • This effort is consistent with the Water Forum agreement, which helps balance water supply and the environment in the Lower American River by using both surface water and groundwater resources.

Long-lasting opportunities for water management

With this agreement and three year pilot, Roseville and SMUD will better understand the real-world process of in-basin transfers. This is a critical step towards water supply planning in the area, particularly as the Sacramento region embarks on creating a regional groundwater bank in the near-term. Establishing a precedent now with the U.S. Bureau of Reclamation could help pave the way for other in-basin transfers that’ll help the region manage surface water and groundwater supplies in preparation for future dry years.