Alameda County — While a pair of reports recently completed by the Zone 7 Water Agency stated that the agency is well positioned to meet the water needs of the Tri-Valley for the next 20 years, the agency is investing in a number of projects to improve the reliability of the region's water supply.
The Delta Conveyance Project — a version of what was once known as the Twin Tunnels project — figures prominently in Zone 7’s long-term plans.
The tunnel project has had several names and gone through a number of iterations over the years, including the change from two tunnels to one. The current version of the plan will draw water from the northern reaches of the Delta and deliver it to pumping plants in Tracy via a 35-mile-long tunnel buried 150 feet below ground. The Department of Water Resources (DWR) states that its project will protect Delta-based water delivery from earthquakes and saltwater intrusion. However, environmentalists wishing to protect the Delta from saltwater intrusion and other impacts continue to express concerns.
The Tri-Valley receives a majority of its water from the Sacramento-San Joaquin Delta.
“We’re highly reliant on imported water,” explained Amparo Flores, integrated planning manager with Zone 7. “That’s how the Tri-Valley area was developed. We have a local groundwater basin, which is a huge asset. But that was overdrawn decades ago. What the State Water Project (SWP) has been able to do is bring in surface water to recharge the groundwater basin. Right now, 80 to 90% of our (water) supply comes through the Delta. That is a huge part of bolstering the reliability of the system. It's a huge issue for the Tri-Valley.”
More immediately, Flores said the agency recognizes that the existing supplies could “use some improvements in terms of reliability.”
“We have been pursuing a number of water supply projects and also infrastructure projects to bolster the reliability of our system. In the Urban Water Management Plan, we present those plans,” Flores said. “That’s essentially what it’s doing. You’re presenting your existing system and any improvements you’re planning – how you’re going to meet demands over the next 20 years.”
The DWR requires all water agencies, both retailers and wholesalers, to file an Urban Water Management Plan (UWMP) and a Water Shortage Contingency Plan (WSCP) with DWR every five years.
The UWMP takes a long-term view, while the contingency plan addresses actions taken to address short-term shortages. And while drought conditions can create short-term water supply issues, Steve Aguiar, City of Livermore interim division manager, clarified that it’s not the only threat. He noted that infrastructure failure, wildfire and earthquakes all have the ability to interrupt water service.
Geography plays a role in another of Zone 7’s most immediate concerns. Much of its water is stored south of the Tri-Valley – downstream of the agency’s customers. Getting access to that water could be difficult when it’s needed most.
“One of the challenges of the Tri-Valley water supply is that we don’t have storage upstream of us,” Flores said. “We’ve invested heavily in groundwater banks in Kern County. We have water stored there, but it’s downstream of us. That means we can only access that water through an exchange. Water has to be coming from up north. Water has to be available up north that we can take through the Delta, and somebody else takes the water downstream of us. But that water has to be delivered through the Delta.”
To resolve this issue, Zone 7 is one of 30 agencies investing in the Sites Reservoir. Located 10 miles west of the town of Maxwell in Glenn and Colusa counties, the reservoir will eventually provide an average of more than 200,000 acre-feet of water a year. An acre-foot is the amount of water needed to cover one acre in one foot of water. It is roughly equal to 326,000 gallons of water, about the volume of water used by two California households in a year. It is expected to be fully functional by 2030.
Importantly for the agency, the Sites Reservoir’s location to the north means that water stored there can be moved south through the Delta to the Tri-Valley virtually on demand. For similar reasons, the agency is also participating in the expansion of the Los Vaqueros Reservoir located between Livermore and Brentwood. That project will include the construction of a pipeline that will connect it directly to the South Bay Aqueduct.
Other projects getting attention from Zone 7 include potable water reuse and desalination. Consumer-level conservation still plays a significant role in water management.
“We should always be in the mindset of conserving water, not just here in Livermore, but in the west in general,” said Aguiar. “It’s an arid region. We import a lot of water through the State Water Project.”
A 10% voluntary reduction of water use already in place, and no end in sight for the dry hot conditions currently gripping the area.
“With this year, everybody’s talking about how special it is,” Flores said. “With a 5% (SWP) allocation, a critically dry year following a dry year coming on the heels of the last drought, we’re just getting slammed. These are conditions that are historically rare, but with climate change, we’re all bracing for these conditions that will strain our system. We’re learning a lot from how we respond to these conditions.”