Development of Six Groundwater Sustainability Plans for Salinas Valley

M&A was the lead consultant that developed the Groundwater Sustainability Plan for the 180/400-Foot Aquifer Subbasin in the Salinas Valley, which was submitted January 2020. We are managing and developing five other Salinas Valley subbasin GSPs to be submitted January 2022.


M&A is the lead consulting firm developing Groundwater Sustainability Plans (GSPs) for the six separate subbasins within the Salinas Valley Basin. We developed the GSP for the critically over-drafted 180/400-Foot Aquifer Subbasin, which was submitted in January 2020. We are working closely with the Salinas Valley Basin Groundwater Sustainability Agency (SVBGSA) by developing technical content, providing policy strategy, and coordinating with various stakeholders in the five other subbasins. The Salinas Valley Basin is primarily agricultural with an important source of surface water supply, which is managed conjunctively with groundwater pumping to meet agricultural, urban, and domestic needs. Sustainability in the Salinas Valley depends on M&A working with other water agencies and regulators to successfully integrate the surface water operations with the groundwater pumping system.


M&A leads both the technical aspects of the GSP, such as developing the hydrogeologic conceptual model, and the policy aspects such as developing sustainable management criteria and establishing the projects and actions that will achieve sustainability. Working collaboratively with the GSA and stakeholders, M&A created an approach for jointly developing all six GSPs in the Valley. The approach acknowledges the unique geologic and hydrogeologic aspects of each subbasin, while simultaneously developing unified groundwater management solutions that cross subbasin boundaries and leverage all of the water resources in the Salinas Valley. This innovative approach meets the competing objectives of obtaining stakeholder buy-in and having ample resources to solve the Valley’s groundwater problems.

The hydrologic conceptual model developed by M&A provides the hydrogeologic framework or aquifer layering and characterization of the groundwater system. This project involved evaluating and updating a previous investigation of regional and local information regarding physiography, climate, hydrogeology, groundwater levels and groundwater movement, surface water features, recharge, hydraulic properties for the aquifer units, discharge including well pumping, and groundwater salinity.

Water Policy and Economics

  • Develop sustainable management criteria

Groundwater Modeling

  • Develop the hydrologic conceptual model and groundwater budgets

Groundwater Management

  • Provide technical and regulatory advice to the GSA on SGMA requirements
  • Consider local groundwater management planning activities
  • Develop and present technical content at planning and advisory committee meetings and at GSA Board meetings
  • Develop a roadmap for GSA funding mechanisms during early SGMA implementation
  • Develop grant applications for DWR GSP development and implementation funding

Data Management Services

  • Develop a robust data management and mapping system with a web interface and data download capabilities