180/400 Foot Aquifer Subbasin

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 its 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 must be submitted to DWR with a Periodic Evaluation that explains and supports the changes. SVBGSA and partner GSAs prepared the 180/400 GSP Amendment 1 in 2022 and submitted in 2025 to align the plan with the Salinas Valley GSPs adopted in 2022. In response to DWR’s required revisions to the sustainability goals, SVBGSA and partner GSAs are preparing GSP Amendments for submittal with the 2027 Periodic Evaluations. The 180/400 GSP Amendment 2 will replace Amendment 1. For more information on the 2027 Salinas Valley GSP Amendments and Periodic Evaluations, see the Fact Sheet.