Definitions (Glossary)

Definitions are from California Code of Regulations, Title 23. Waters, as referenced in the Sustainable Groundwater Management Act and Groundwater Sustainability Plan Emergency Regulations. 

acre-foot (af) means the volume of water that would cover 1 acre to a depth of 1 foot; equal to 43,560 cubic feet or 325,851 gallons. An acre-foot of water is considered enough water to meet the needs of two families of four for one year. 

Basin Prioritization is the classification of groundwater basins based on a variety of factors identified in statute, such as population and the number of water wells in a basin (see Water Code § 10933). DWR was first directed to prioritize basins as part of the Groundwater Monitoring legislation adopted in 2009, which established the order in which DWR would evaluate basins to determine whether monitoring provided sufficient information to demonstrate seasonal and long‐term trends in groundwater elevations, as required by that law.  DWR created the California Statewide Groundwater Elevation Monitoring (CASGEM) Program in response to the Groundwater Monitoring legislation, and released the CASGEM prioritization of basins in 2014. The Sustainable Groundwater Management Act (SGMA), which became effective in 2015, required DWR to prioritize basins for purposes of SGMA shortly after the law took effect (see Water Code § 10722.4). DWR implemented the 2014 CASGEM Basin Prioritization as the initial SGMA Basin Prioritization in 2015. 

Basin means a groundwater basin or subbasin identified and defined in Bulletin 118 or as modified pursuant to Chapter 3 (commencing with §10722). 

Basin Boundary Modification (BBM) means a change to the boundary of a basin or subbasin. The Sustainable Groundwater Management Act (SGMA) established a process for local agencies to ask the Department of Water Resources (DWR) to revise the boundaries of existing groundwater basins or subbasins, including establishing new subbasins. 

Basin Setting means the information about the physical setting, characteristics, and current conditions of the basin as described by the Agency in the hydrogeologic conceptual model, the groundwater conditions, and the water budget, pursuant to Subarticle 2 of Article 5.

Best Available Science means the use of sufficient and credible information and data, specific to the decision being made and the time frame available for making that decision, that is consistent with scientific and engineering professional standards of practice. 

Best Management Practice means a practice, or combination of practices, that are designed to achieve sustainable groundwater management and have been determined to be technologically and economically effective, practicable, and based on best available science. 

Bulletin 118 means the DWR report entitled “California’s Groundwater: Bulletin 118” updated in 2003, as it may be subsequently updated or revised in accordance with §12924.

Coordination Agreement means a legal agreement adopted between two or more groundwater sustainability agencies intending to develop and implement multiple Plans to ensure that the Plans are developed and implemented utilizing the same data and methodologies, and that elements of the Plans necessary to achieve the sustainability goal for the basin are based upon consistent interpretations of the basin setting. 

Data Gap means a lack of information that significantly affects the understanding of the basin setting or evaluation of the efficacy of Plan implementation and could limit the ability to assess whether a basin is being sustainably managed. 

De Minimis Extractor means a person who extracts, for domestic purposes, two acre-feet or less per year. 

Governing Body means the legislative body of a Groundwater Sustainability Agency (GSA). 

Groundwater means water beneath the surface of the earth within the zone below the water table in which the soil is completely saturated with water, but does not include water that flows in known and definite channels. 

Groundwater Recharge or “Recharge” means the augmentation of groundwater, by natural or artificial means.