Santa Maria River Valley Groundwater Basin


In 2015, the State legislature approved an important new groundwater management law known as the Sustainable Groundwater Management Act (SGMA). DWR designated Santa Maria Basin as a high priority basin. SGMA requires that high and medium priority basins comply with the new law, with certain exceptions for certain adjudicated basins such as the Santa Maria Basin. SGMA does not apply to the portion of the Santa Maria Basin that is at issue in the litigation (“adjudicated area”) provided that certain requirements are met. The adjudicated areas cover a majority of the basin, and are managed by the Northern Cities Management Area, Nipomo Mesa Management Area, and the Santa Maria Valley Management Area. For the fringe areas, which are the non-adjudicated areas outside the adjudicated portion of the basin, the County of San Luis Obispo, the City of Arroyo, and the County of Santa Barbara formed groundwater sustainability agencies to manage the basin areas within their respective jurisdictions. The non-adjudicated basin fringe areas must comply with SGMA requirements.

As a result of DWR’s decisions on the final 2018 basin boundary modification processes in February 2019, three of the Santa Maria Basin fringe areas were removed from the basin and the Arroyo Grande Creek fringe area was established as a subbasin (see “Final Basin Boundary Modifications Release” in Recent News Section below for more details). The map below displays both the adjudicated areas exempt from SGMA, and the newly modified basin boundaries, which shows the remaining fringe areas that are subject to SGMA.

For information specific to the Arroyo Grande Subbasin, please click here.

Recent News & Announcements

Final Basin Boundary Modifications Released

The California Department of Water Resources (DWR) has released the 2018 Final Basin Boundary Modifications decisions and accompanying documents. 

Click on the following links to view the 2018 Final Basin Boundary Modifications results:

For additional information, please visit DWR’s Basin Boundary Modifications website by clicking here.


Prioritization for Modified Basins Released

On December 18, 2019, DWR announced completion of the Phase 2 Basin Prioritization, designating the Santa Maria and Arroyo Grande Subbasins as very low priority.

Click Here for Archived News & Announcements

Meeting Calendar - Agendas and Minutes

How do I get involved?

Interactive Map of Santa Maria River Valley Groundwater Basin 

Welcome to the SGMA Interactive Data Viewer for the Santa Maria Groundwater Basin! This is an interactive mapping system to help you to navigate around the Santa Maria Groundwater Basin by panning, zooming, or searching for a specific parcel or street address that you would like to locate. There are different map layers that can be shown and superimposed in this interactive mapping system such as boundaries of groundwater basins, cities, roads, SGMA eligible entities, and others by checking the layer names indicated on the left panel layer menu. To search and locate a specific APN or street address on the map:

  1. Enter either the nine-digit parcel number (APN) including hyphens or the complete street address in the “Search...” bar on the upper right hand corner of the map screen and then click on the search button to locate it. The APN or street address that you just entered will appear on the left panel and a location marker will show up on the map to identify the location.
  2. Click on the APN or street address name shown on the left panel layer menu will zoom in to the specified location for a close-up look

Sign up for the SGMA Mailing List

Click here to subscribe to the SGMA email notification list!