The fight against seawater intrusion in the Salinas Valley Groundwater Basin is about to get a lot more real.
On Nov. 14, Monterey County Water Resources Agency Senior Hydrologist Howard Franklin presented six different recommendations to the County Board of Supervisors that aim to help slow or halt the intrusion, which has advanced in alarming ways over the last few years.
The stakes are high, and hard to overstate: Advancing seawater intrusion, in which seawater fills in underground aquifers when freshwater is pumped, threatens water supplies in the lower Salinas Valley, putting many millions – if not billions – of dollars’ worth of agricultural operations at risk, as well the municipal water supplies of Salinas and Marina.
Those threats were first made clear in a presentation Franklin gave on July 11 to the county supervisors and the Water Resources Agency board of directors. He showed data revealing the extent of seawater intrusion in 2015 – the most recent year for which the county has crunched the data – showing that not only had the intrusion advanced since 2014, but confirmed a new, troubling phenomenon.
The 2015 intrusion maps showed two “islands” of seawater intrusion in the 400-foot aquifer, named for its depth, that were not contiguous to the primary affected area.
On Nov. 14, Franklin outlined his recommendations to the supervisors. Most notably, they included a moratorium on new wells in the 400-foot aquifer in the “area of impact” – an area stretching from the coast to nearly as far east as Highway 101 in North Salinas – as well as a moratorium on new wells in the “deep aquifer,” an ancient water source 900-feet-plus deep that hydrologists say is recharging only due to leakage from overlying aquifers. That deeper aquifer, which extends roughly as far inland as Chualar, has increasingly become a water source for growers in the impact area as their shallower wells are affected by seawater.
Franklin was clear, however, that even if the recommendations are implemented, it would not likely reverse the intrusion in his lifetime.
“What we’re really talking about here today is protection,” Franklin said, “about halting or slowing further advancement. If we don’t take some action soon, we’re going to lose most of the 400[-foot aquifer] in the area of impact that isn’t already intruded by seawater.”
All the supervisors were on board with all six recommendations, and they asked Franklin to bring back an ordinance to enact the moratoriums on new wells as soon as possible. “It’s obviously a matter of urgency, especially for those of us in my district,” said Supervisor John Phillips, who represents North County.
“Seawater intrusion is relentless and it’s moving down the valley,” Supervisor Jane Parker said. “I hope we do pursue all of [the recommendations].”
Monterey County Counsel Charles McKee says his staff will work on determining which agency has authority to enact the recommendations. (There may be overlap with the newly formed Salinas Valley Groundwater Sustainability Agency, which adds a layer of complexity.) He plans to present on the options to enact Franklin’s recommendations – and who can legally implement them – on Dec. 12.