On May 9, staff from the Salinas Valley Basin Groundwater Sustainability Agency presented its board a long-awaited study about the so-called Deep Aquifers, which have been increasingly mined in recent years as seawater intrusion marches inland toward the city of Salinas.
The problem is, those aquifers – which in the report are defined as being below a layer of clay separating them from the 400-foot deep aquifer – aren’t recharging.
The report states: “Isotopic analysis indicates the areas sampled have received no recharge [from surface] water since at least 1953.”
Taken as a whole, the nearly 150-page report is a bombshell.
“Despite chronic groundwater elevation declines in most Deep Aquifers wells, well installations continued.” It goes on to conclude that “groundwater conditions of the Deep Aquifers continue to degrade,” and that “seawater intrusion and subsidence pose severe economic risk if declining groundwater elevation trends are not reversed.”
Even though the risks had long been known, or least suspected, the County of Monterey for years approved new agricultural wells ministerially, and only in 2018 did the Board of Supervisors pass a moratorium on drilling new wells into the Deep Aquifers for agriculture, with the exception of replacement wells.
That came after growers drilled deep wells on the former Armstrong Ranch property north of Marina and have since been pumping all they need from the finite water resource that is also a critical water supply source for Marina Coast Water District’s service area, which extends as far south as some parts of Seaside and even Del Rey Oaks, and as far east as East Garrison.
The SVBGSA was created in response to the state’s Sustainable Groundwater Management Act passed in 2014. The law requires that sustainability be achieved by 2042.
Sarah Hardgrave, SVBGSA’s deputy general manager, says the study provides the “scientific basis” to inform decision makers, and that right now, the agency is working mainly on two potential plans to bring the northern valley’s aquifers into balance: One is extracting brackish water near the coast and treating it, and the other is creating additional diversions from the Salinas River and injecting water in an aquifer storage and recovery project like the one the Monterey Peninsula Water Management District pioneered locally in the 2000s – essentially, an underground reservoir.
Who will pay for all of that? That’s a question the SVBGSA is now wrestling with, and if history is a teacher, it will be argued about for years to come.
Landwatch Monterey County, an anti-sprawl nonprofit that often weighs in on water issues, sent a letter to the Board of Supervisors May 6 stating, “In view of the GSA’s dilatory approach to taking needed action, especially if that action limits new wells or pumping, the County can and should use its authority over well permitting and its authority to regulate groundwater pumping to implement the no net increase rule, immediately.”