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 Implementation Committee meets every month on the first Thursday at 1 p.m. Get meeting information.
Key Documents:
- The Groundwater Sustainability Plan (GSP) was submitted to the Department of Water Resources (DWR) on January 23, 2020.
- GSP Amendment 1 (updates original 2020 GSP) was drafted in 2022 to align with the other Salinas Valley Basin GSPs, and will be submitted in January 2025 together with 2025 Periodic Evaluation
- GSP Amendment 1 Appendices
SVBGSA has supported partner agencies to begin improvements to the Castroville Seawater Intrusion Project to increase the use of recycled and surface water for irrigation in the seawater-intruded area. SVBGSA is also undertaking feasibility studies to assess options for addressing seawater intrusion.
SVBGSA is undertaking feasibility studies to address seawater intrusion including:
SVBGSA is also studying the Deep Aquifers.
The complete document can be downloaded here:
A GSP 5-Year Evaluation under California’s Sustainable Groundwater Management Act (SGMA) is a periodic review conducted by Groundwater Sustainability Agencies to assess the effectiveness and progress of their groundwater management efforts. The first 5-year evaluations for critically overdrafted basins like the 180/400-Foot Aquifer Subbasin were due to DWR in January 2025, as noted in the Executive Summary. SVBGSA Board received the GSP 5-Year Evaluation at their meeting on January 9, 2025, and the report has been submitted.
Key findings and the associated sections include:
- A summary of how most data gaps have been filled and monitoring networks expanded.
- New data and models update the basin’s understanding of aquifers, groundwater conditions, and water budgets.
- A summary of groundwater conditions over the past 5 years
- A description of work underway to conduct feasibility studies and develop a plan for reaching groundwater sustainability.
- During this 5-year evaluation period, the GSAs have ramped up outreach, engagement, and coordination, both with stakeholders and partner agencies
Appendixes
- 3A. Groundwater Elevation 5-Year and 20-Year Linear Regressions for RMS Wells
- 3B. New Deep Aquifers RMS Data and SMC Development
- 3C. Analysis of Relationship Between Seawater Intrusion, Groundwater Elevations, and Extraction
- 3D. Annual Groundwater Quality Regulatory Limit Exceedances from 2017 to 2023
- 3E. Subsidence Analysis
- 5A. HCM Update Data, Methods, and Results
- 5B. GDE Identification and a GDE Monitoring Standard Operating Procedures (SOP)
- 5C. Updated Water Budgets
- 6A. Changes to RMS Monitoring Networks
- ES-A. Resolution No. 2022-16
- ES-A. Assessment
- ES-B. Resolution No. 2022-16
Annual Reports are a progress tracking tool that document current groundwater conditions for each water year and summarize GSP implementation progress made that year.
- 180/400-Ft Aquifer Subbasin Water Year 2023 Annual Report (PDF)
- 180/400-Ft Aquifer Subbasin Water Year 2022 Annual Report (PDF)
- 180/400-Ft Aquifer Subbasin Water Year 2022 Annual Report Dashboard (PDF)
- 180/400-Ft Aquifer Subbasin Water Year 2021 Annual Report (PDF)
- 180/400-Ft Aquifer Subbasin Water Year 2020 Annual Report (PDF)
- 180/400-Ft Aquifer Subbasin Water Year 2019 Annual Report (PDF)