As drought presses on, Castroville’s drinking water supply drops to unprecedented lows.

Before there was Hetch Hetchy, there was Castroville.

An 1896 article in San Francisco Call described an engineer’s scheme to quench the water needs of the growing San Francisco Bay Area: For $6.5 million, he’d lay steel pipe and pump “a cheap, ample and pure water supply” from the Castroville Lakes up north.

In those days, the lakes were as deep as 350 feet. They promised “a system that might solve the water problem for all time,” according to the newspaper article.

It was a literal pipe dream. Not only have those lakes since been drained, but even the stressed aquifer below Castroville is hitting unprecedented lows.

Overpumping from the Salinas Valley Groundwater Basin isn’t new. The resulting seawater intrusion was first documented in 1946, ruining farm fields in Castroville and Moss Landing, as seawater seeped in from Monterey Bay.

Seawater intrusion can destroy municipal wells, too. The Castroville Community Services District delivers water to some 7,000 families, from the same aquifer neighboring farms use. Groundwater levels at the district’s three wells are lower than ever, dropping to 30, 70 and 102 feet below sea level in early August.

“Any time they’re below sea level, the clock is ticking,” says Eric Tynan, general manager of CCSD. “Once a well starts turning [salty], the numbers don’t creep – they go straight up.”

Tynan is at work on new wells in hopes they don’t hit saltwater. One is much deeper than the existing wells, but that comes with a cost. The district will need to treat the water for naturally occurring arsenic, building a $1.2 million plant with help from a state grant. Those will likely come online by the end of this year, but CCSD still has to ride out another month or so of intensive agriculture.

To help relieve seawater intrusion, Monterey County Water Resources Agency has built several projects to provide farmers with other water sources.

But due to drought, there isn’t enough water flowing down the Salinas River to work the rubber dam in Marina, so growers resort to their wells. “Everyone puts a straw in upstream of us, and by the time it gets to Castroville, there’s nothing left to recharge the basin,” Tynan says.

He’s been meeting with North County Supervisor John Phillips and an Ocean Mist Farms official to look at potential, voluntary changes to the farm’s pumping.

The water resources agency has the authority to make farms reduce their pumping, but they probably won’t. “Last time we did,” Deputy General Manager Rob Johnson says, “we got engaged in a very large lawsuit.”