Two key water studies launched this month

Two major studies that directly effect the quality and cost of the Tri-Valley’s drinking water got underway this month.

In Sacramento, the Newsom Administration formally announced it will pursue a single large tunnel to move Sacramento River water south from Sacramento to the Banks pumping station near Tracy. The single-tunnel approach differs from the twin tunnels that former Gov. Jerry Brown pushed for the eight years of his term and could not get moving forward. Prior Gov. Arnold Schwarzenegger had re-initiated Delta studies during his terms.

Meanwhile the Livermore Valley’s wholesale water and flood control agency, Zone 7, launched a $1 million study on improving the valley’s water supply in partnership with the cities of Pleasanton and Livermore and the Dublin San Ramon Services District. The agencies will split the cost. The analysis will include the Delta Conveyance as well as treating and re-using sewage effluent, the expansion of Los Vaqueros Reservoir south of Brentwood, and a potential desalination plant in the west Delta.

It will also consider participation in the proposed Sites Reservoir, which would be off-stream near Maxwell with water pumped in during high winter flows and then released in place of cold water from Lake Shasta during the warmer months. That’s how the giant San Luis Reservoir operates south of the Delta near Los Banos. Sites would allow Shasta water to be preserved for key times for salmon runs that need the colder water to spawn. Sadly, even though state voters passed $3 billion in a 2014 bond for storage, no money has been allocated to Sites despite its win-win-win from fish, policy and operations standpoints.

Both projects are critical for the valley’s future water supply. I suspect the local study will show some advantages for diversifying the water sources. In a normal year, 80 percent of the water used locally comes through the Delta pumps and flows in the South Bay Aqueduct through the valley. You can see the branch cross under Interstate 580 as you climb the Altamont Pass.

That dependence on Delta conveyed water is why the Zone 7 board has previously voted in favor of participating in the project. There’s lot of hype and hysteria around the Delta, but there’s little question that the current system is not working. Water supplies are limited, fish populations (particularly the Delta Smelt) have crashed although salmon runs have been up and down because of the drought.

It’s important to remember that the State Water Project always included a Delta conveyance. The current system of diverting Sacramento River water south through Delta channels disrupts the east-west flow and makes the river run north to south. A tunnel would allow the Delta at some times to flow naturally although it’s likely that the tunnel will be use in tandem with the cross-Delta channels. The newly launched Delta study will help determine the uses. More than 27 million people drink water from the Delta, including almost 3 million in the valley, the Fremont area and the South Bay..

So, stay tuned to see if this project, that has been going for 13 or more years, ever gets off the drawing board,