A local effort is underway to build an inventory of smaller wells, but it is slow going.

For the first time, thanks to mandates from the state’s Sustainable Groundwater Management Act (SGMA), a local effort to collect reliable data on small, private wells in the Salinas Valley groundwater basin is underway.

The effort, run by the Monterey County Water Resources Agency (MCWRA) in partnership with the Salinas Valley Basin Groundwater Sustainability Agency (SVBGSA), aims to fill a major data gap under SGMA by building an inventory of these wells to assess their vulnerability and create drought contingency plans.

“We are not asking rural residents to report the extractions,” says Piret Harmon, general manager of SVBGSA. “Because the hydrogeology is quite complex, it makes a big difference where exactly and how deep they are, how old they are, because that’s the only way we can truly understand where we need to focus our efforts in assuring everyone has sustainable groundwater.”

Big picture, residential groundwater use is relatively small; agriculture accounts for 90 percent of groundwater use in Monterey County. Many private, smaller wells are shallow and disconnected from larger water systems, making them more vulnerable during droughts.

While the data is critical for identifying areas of concern that may require specific emergency planning or new infrastructure, a challenge has been getting people to register.

“We think right now, about 5 percent of the people who we were hoping to have registered have registered with us,” says Amy Woodrow, senior hydrologist with MCWRA. The deadline was extended from Jan. 31 to March 31 due to low initial registration. (Registration is free; call (831) 755-4860 or visit svbgsa.org/gmp.)

Officials estimate thousands of wells will need to be registered, although the exact number is unknown. The estimate is based on County Health Department well permits, state well-drilling records, and parcels known to not be part of a water system.