Groundwater terminology can be technical and complex. This glossary defines key terms and acronyms used throughout the site and in SGMA-related documents, ensuring visitors can understand the language of sustainability.

Acre-foot – The amount of water needed to cover one acre of land one foot deep (about 326,000 gallons).

Alternative Submittal – A plan submitted to the California Department of Water Resources as an alternative to a standard Groundwater Sustainability Plan (GSP). SCGA’s 2017 Alternative Submittal demonstrated existing local groundwater management systems that met SGMA requirements.

Aquifer – A natural underground layer of rock or sediment that holds groundwater.

BMOs (Basin Management Objectives) – Locally defined goals for maintaining or improving groundwater conditions in the basin. BMOs may cover groundwater levels, water quality, or storage capacity, and serve as triggers for management responses if thresholds are not met.

Basin/Subbasin – A groundwater area defined by natural or jurisdictional boundaries. SCGA manages the South American Subbasin (SASb).

CASGEM – California Statewide Groundwater Elevation Monitoring program. SCGA’s monitoring wells are part of this network.

GSA (Groundwater Sustainability Agency) – A local agency authorized to manage groundwater under SGMA.

GSP (Groundwater Sustainability Plan) – A long-term planning document that lays out how a GSA will achieve sustainable groundwater use.

HydroDMS – A data management system used by SCGA to store, analyze, and visualize groundwater level and quality data. HydroDMS supports GSP implementation by generating maps, reports, and time-series data to track BMOs.

JPA (Joint Powers Agreement) – The legal document that formally created SCGA in 2006. The JPA outlines the agency’s structure, authority, and funding responsibilities. It was amended in 2022 to reflect updates in governance and SGMA responsibilities.

Monitoring Network – A system of wells and sensors used to track groundwater levels, quality, and conditions over time.

Overdraft – When more groundwater is withdrawn than is naturally or artificially recharged.

Recharge – The process of water soaking into the ground to replenish an aquifer.

Rules of Procedure – A set of formal guidelines adopted by the SCGA Board to govern meetings, officer elections, board conduct, committee appointments, and other procedural matters.

SASb (South American Subbasin) – The groundwater subbasin located in Sacramento County that SCGA manages under SGMA. It is part of the larger Sacramento Valley Groundwater Basin.

SGMA (Sustainable Groundwater Management Act) – The California law that requires sustainable groundwater use and created the framework for GSPs.

Sustainability Indicators – Six metrics required under SGMA to track groundwater basin health, including groundwater levels, quality, storage, seawater intrusion, land subsidence, and depletion of interconnected surface water.