180-400ft Aquifer Subbasin Map

Situated in the northern region of Monterey County, the 180/400-foot Aquifer Subbasin encompasses Castroville, Salinas and Gonzales. Most of the subbasin has a layered aquifer system with three aquifers separated by aquitards. The upper two aquifers have seawater intrusion, which is why the state categorized the subbasin as critically overdrafted and requires earlier implementation of SGMA.

The 180/400-Foot Aquifer Subbasin Committee meets on the first Thursday of even months at 1 p.m. Get meeting information.

Groundwater Sustainability Plan:

Groundwater Sustainability Plans provide a long-term framework for managing groundwater in accordance with California’s Sustainable Groundwater Management Act (SGMA). The 180/400 Subbasin GSP describes groundwater conditions, establishes measurable sustainability goals, and identifies the projects and management actions needed to achieve and maintain groundwater sustainability.

As needed, a GSA may amend a GSP.  A GSP Amendment formally revises an adopted GSP when changes are needed to its management approach, sustainability criteria, projects, management actions, or other core elements. Amendments require specific public notice and adoption procedures and must be submitted to DWR with a Periodic Evaluation explaining and supporting the changes.

Draft 180/400 Foot Aquifer Subbasin GSP Amendment 2

Periodic Evaluations are comprehensive assessments of GSP implementation prepared at least once every five years. They evaluate whether implementation is meeting interim milestones and remains on track to achieve the groundwater sustainability goal. They also consider new information, changes in groundwater conditions, monitoring improvements, and whether revisions to the GSP may be warranted.

Annual Reports provide a yearly update on groundwater conditions and GSP implementation. They summarize monitoring data from the previous water year, evaluate conditions in relation to the GSP’s sustainability criteria, and report progress on projects, management actions, and efforts to address data gaps. Annual Reports are submitted to the California Department of Water Resources (DWR) by April 1 each year.