After Monday’s rains in the Bay Area, it may be difficult to focus on the fact that climate change is threatening deeper and more frequent droughts. But water managers in the South Bay just struck a deal that will add a huge amount to their storage by expanding the San Luis Reservoir in Merced County.
Just off Highway 152, between I-5 and the town of Gilroy, is the San Luis Reservoir, the fifth largest reservoir in California, and it is entirely man-made. The chances that it could be built today are highly unlikely, but the fact that it already exists provides a huge opportunity for additional water storage for the southern Bay Area.
But in 1962 it was just a dry valley surrounded by rolling hills. Just then, a young, ambitious President John F. Kennedy arrived to show what it takes to lead a fast-growing country into the future.
“In another 40 years, there will be 300 million people in this country. Many of them will live in California,” Kennedy told a crowd of people at the site. “In many ways, California’s growth problems and conservation problems are the same kinds of problems facing our country. It’s a pleasure for me to come here and help revitalize this valley to further progress,” he said. , while the audience laughed.
With that, he pushed a plunger, detonating dynamite in an explosive groundbreaking for the construction of the 350-foot dam that would create the San Luis Reservoir. That’s how they did it back then. And since then, the water supply created has benefited from the South Bay to the Central Valley. But Kennedy’s predictions about population growth were correct, and now water demand is once again a challenge for the state.
“We need to be resilient to drought. We need to adapt to climate change. We need water as these drier times arrive,” said Aaron Baker, Chief Operating Officer of Santa Clara Valley Water.
He said they have reached an agreement with seven other agencies to pay nearly $1 billion to raise the dam level of the reservoir by 10 feet. That may not sound like much, but given the size of San Luis, this equates to 130,000 hectares, enough for about 260,000 households per year. Of that, almost half – 60,000 hectares – will go to Valley Water.
“Sixty thousand acres is quite a bit of water,” Baker said. “If we want to put it in the Anderson Reservoir, our local reservoir is currently about 90,000 acres. This will be 2/3 of the Anderson Reservoir.”
Because Santa Clara Valley Water will receive the majority of the water storage, they will pay the largest cost, approximately $430 million. The eight participating water agencies planned to meet with federal officials in Washington, D.C., on Wednesday to commemorate the agreement they reached. But it only happens because of what they did in 1962.
“This is an existing reservoir,” Baker said. “All the plumbing is already in place. Valley Water is already receiving deliveries from this reservoir, and many others are receiving deliveries from this reservoir. So the amount of infrastructure that has to deal with this kind of thing is really just a dam increase.”
For that reason, the San Luis project has not faced the same roadblocks from environmental groups as others. And because the dam is currently undergoing federal seismic safety construction, dam elevation can be coordinated with that activity. But it won’t be a quick fix.
“It’s going to take some time,” Baker warned. “Right now we need to make sure we work with the existing ‘Safety of Dams’ project. And so it is now estimated that construction will be completed around 2032.”
The dam construction project, like the reservoir itself, is a forward-looking idea – recognizing that it is the vision of people from the past that people in the present rely on every day.
John Ramos
