Managing our water supply


Sustainably Managing Our Water Supply

The one thing we can rely on when it comes to our forecast is California’s predictably unpredictable climate. This means we need to be prepared for any type of season and think long-term about how best to meet our community’s long-term water supply needs, while still delivering on Tri-Valley’s immediate needs.

We do this through a multi-strategy approach to water reliability.


Cracked dry ground surrounded by dry grass

The process begins with annual and ongoing forecasting. In partnership with the California Department of Water Resources (DWR) State Water Project, climatologists make scientific predictions about what kind of weather year we will have.

We then look at how this will impact Zone 7 and the Tri-Valley’s water resources to make decisions about how we can meet our community’s needs with our available resources.


Groundwater Recharge

Aerial view of the Delta river, surrounded by green landscape

In rainy years, local streams and surrounding habitats receive natural moisture that helps fill our groundwater basin. In addition to natural recharge, as part of our commitment to sustainably manage the basin, we also take advantage of wet years by artificially recharging the basin with imported water to prepare for dry years and protect the overall health of the basin.


Aerial view of San Luis Reservoir with mountains surrounding the reservoir

Stored or “banked” water is an exchange system we have with our neighbors and the State Water Project. Zone 7 has “storage space” in San Luis Reservoir and in Kern County’s Semitropic and Cawelo water storage districts. We use part of our stored water from San Luis Reservoir, our most readily available State Water Project source, to supplement our local water supply annually.

When we need to “cash-out” our banked water, we take the additional water from our imported State Water Project sources. Each year, we must decide if, and how much, we must use from our stored accounts in the Kern County banking programs to augment our allocation and natural supplies.


Front Yard of a home featuring native bushes and flowers

In particularly dry years, we have called on our community to conserve – and the Tri-Valley has answered that call. In fact, we have done a great job of changing our water-wasting habits and those savings have continued in non-drought years.

Now is the time for us to prepare for the next level of conservation. Outdoor water savings offer our best opportunities for managing this precious resource. Check out our conservation section to learn more about how you can be water wise.

Future storage and supply projects

The Agency’s 2019 Water Supply Evaluation Update confirmed the need for new water supplies to maintain Zone 7’s commitment to water reliability. Several projects are in the study or planning phases to determine the best way to achieve the needed supplies in the future. These projects include the Sites Reservoir Project, the Delta Conveyance Project, the Los Vaqueros Expansion Project, Potable Reuse and the Bay Area Regional Desalination Project. These projects are all in varying states of planning or initial study. They vary in benefit to the Tri-Valley water supply system. Some provide new water supplies, some storage opportunities for increased resiliency and some provide alternate conveyance for increased operational flexibility. To meet the future demands of the Tri-Valley, Zone 7 must consider a combination of these projects. The costs and benefits of each is being carefully evaluated. To stay updated on our participation in these projects, please sign up for our monthly enewsletter.

Sites reservoir Project

Zone 7 Water Agency is currently participating in the Sites Reservoir Project, a planned off-stream reservoir in Northern California. The Sites Project Authority is pursuing a water right permit from the State Water Resources Control Board, which will provide them legal authority to divert water within certain conditions, for a specific purpose, and for use within a specified area. The Sites Project Authority will be the State designated steward of the water right for the Sites Reservoir Project.

Information on the Sites Reservoir Project’s water right application can be found here:

Additional information on the Sites Reservoir Project can be found here:

Los Vaqueros Reservoir