Proposed pipeline between two South County reservoirs could supply the Peninsula.

Lake Nacimiento, nicknamed “the dragon” because of its shape, isn’t deep enough to hold all the water that flows into it. Water officials are now beginning to see that as an opportunity.


Nacimiento fills up three times faster than Lake San Antonio, located a few miles to its north in South County. In the rainy season, extra Nacimiento water is released into the Salinas River for flood control. 


With an 11,000-to-14,000-foot pipeline (or “interlake tunnel”) connecting the two reservoirs, that excess would instead be diverted to San Antonio, which has more than enough capacity to store it. Proponents of the pipeline say it would reduce flood risk along the Salinas River, help prevent seawater intrusion and boost Salinas Valley’s water supply in the dry season. 


The pipeline would also keep lake levels higher in the summer. That’s the goal of the Nacimiento Regional Water Management Advisory Committee (NRWMAC), representing lake-area homeowners and recreational users. 


“They were releasing a bunch of rainwater that was just going to the ocean. Well, that’s a waste,” says NRWMAC President Mark Nielsen. “We needed a big tank to store the extra water in. And the big tank is Lake San Antonio.”


Carmel Mayor Jason Burnett, vice-chair of the Monterey Peninsula Regional Water Authority, asks if the Peninsula could help fund the tunnel project in exchange for a fraction of the water it produces. The water could be transported west using a pipeline already in the planning stages for another project.


“I DON’T WANT IT TO BE SEEN AS THE PENINSULA TRYING TO TAKE SALINAS VALLEY WATER.”


“It’s only going to work if it makes sense for Salinas Valley,” he adds. “I don’t want it to be seen as the Peninsula trying to take some of the Salinas Valley water unless Salinas Valley sees it in their interest.”


Nancy Isakson, president of the Salinas Valley Water Coalition, likes the pipeline’s potential to provide more water for Salinas Valley. But she’s not at all keen on the idea of selling some of it to the Peninsula.


“If I even walked out this door and mentioned it, I’d be shot,” she says. “There’s no way the majority of [the Salinas Valley agricultural community] would get behind it.”


California American Water’s Monterey district is facing a state order to cut back 70 percent of Carmel River pumping by the end of 2016. The quest to replace 10,500 acre-feet of water per year has focused on a proposed $400 million seawater desalination project.


The annual flood-control releases from Nacimiento averaged 53,000 acre-feet per year from 1991-2005, according to a NRWMAC report.


Cal Am spokeswoman Catherine Bowie says company officials are aware of the tunnel idea, but do not believe it could be built before the 2016 deadline. 


The interlake pipeline was included in a 1991 Monterey County Water Resources Agency (MCWRA) list of 34 potential projects to deal with Salinas Valley seawater intrusion. Two decades later, the project has resurfaced as part of MCWRA’s Integrated Regional Water Management Program, a wish-list for the next round of Proposition 84 money available in 2015.


“This is a really good project, and it has multiple benefits for multiple stakeholders,” MCWRA Assistant General Manager Robert Johnson says.


In the meantime, NRWMAC needs funding to further analyze the pipeline idea. Nielsen says the project cost could range from $40 million to $90 million. 


He sees promise in Burnett’s interest. “If the Peninsula could pay for it and they need the water,” he says, “maybe there’s a win for everybody.”