With an eye toward the future, Marina Coast Water District looks to reduce dependence on groundwater.

Since its inception, the Marina Coast Water District has relied on groundwater for its water supply, the majority of which comes from the deep aquifer, an ancient, finite water supply believed to be more than 20,000 years old.

But with the ever-advancing threat of seawater intrusion, an increase in agricultural wells pumping from the deep aquifer, and to fulfill contractual obligations with the Fort Ord Reuse Authority, Marina Coast is looking to further augment its water supply and increase its water security.

On July 16, the Marina Coast board will consider approving a contract for a year-long study of the district’s options to increase its water supply by at least 973 acre-feet, which would fulfill its obligations under the FORA Base Reuse Plan to provide at least 2,400 acre-feet of additional water to its supply (Marina Coast already has 1,427 acre feet of recycled water in the works through an agreement with FORA and Monterey One Water as part of the Pure Water Monterey project.)

But it’s not just contracts motivating Marina Coast.

“How do we ensure we have adequate protections and a diversified portfolio?” says MCWD General Manager Keith Van Der Maaten. “Groundwater is there until it’s not. You don’t want to wait until that day – you want to have a plan ahead of time.”

Add to that, Van Der Maaten says, it’s important that if California American Water’s proposed slant well project in Marina “comes online and starts to ruin the groundwater, we have a plan.” (The question of whether Cal Am’s project would ruin groundwater will likely be determined in court.)

The study will look at the feasibility and costs and benefits of a range of options, including desalination, an expansion of Pure Water Monterey, stormwater capture, and conservation.

The most intriguing option that will be examined is a series of intake wells set far back from the coast that would pump brackish water from seawater-intruded areas, while at the same time injecting freshwater – less, however, than is being pumped from the wells – to form a below-ground freshwater barrier that would stave off further seawater intrusion.

Van Der Maaten has familiarity with the technology because the water district he worked for previously in San Juan Capistrano owned such a facility, and produced water at $1,200 per acre-foot, well below the cost of desal, which is more like $4,000-$5,000 per acre-foot.

Whether such an project would be feasible in Marina – a source would have to be secured for the freshwater injections – remains an open question, but the district is not ruling out any options.

“We’re trying to open it up, and not predetermine the outcome of the process,” says Patrick Breen, Marina Coast’s water resources manager. “Whether Cal Am’s project goes forward might influence where we go with things.”

As for the timing on the study, Breen says the process will require several public meetings and workshops.

“There’s a huge interest in this and how we’re going about what we’re doing,” Breen says. “We’re trying to err on the side of taking our time, and hopefully come up with the best solution.”