Groundwater Info Center
B118 Interim Update 2016 Data
View Basin Boundaries and Download Basin Boundary GIS Data

Basin boundaries, basins subject to critical conditions of overdraft, and basin priorities can be viewed through the following online tools:

Basin Boundary Assessment Tool:

Groundwater Information Center Interactive Mapping Application (GICIMA):

Water Management Planning Tool:

Bulletin 118 Basin Boundaries (2016) GIS Shapefile and metadata available by clicking here.

2016 Updates to Bulletin 118 Basin Boundary Descriptions

Bulletin 118 Update 2003 provided online descriptions of California’s groundwater basins and subbasins.  The basin descriptions included available information on narrative descriptions of basin boundaries, summaries of the hydrologic and hydrogeologic setting, groundwater storage capacity and water budget, groundwater level and quality trends, well yields, basin management, and references.  The full 2003 basin descriptions have not been updated for B-118 Interim Update 2016.  However, DWR developed a new procedure for basin descriptions as part of its basin boundary modification process, implemented in 2016.  As a result, all basins that had boundary modifications in 2016 have revised basin boundary descriptions, which can be viewed below.  The basin boundary descriptions contained in the 2003 basin descriptions are no longer valid for the basins with revised boundaries.

DWR will be updating basin description information as GSAs implement their GSPs, and new and additional information becomes available.

Basins and Subbasins with revised (2016) basin boundary descriptions (click on basin number to open PDF document):

Basin Number Basin Name
1-002.01 Klamath River Valley – Tulelake
5-021.51 Sacramento Valley – Corning
5-021.52 Sacramento Valley – Colusa
5-021.60 Sacramento Valley – North Yuba
5-021.64 Sacramento Valley – North American
5-021.67 Sacramento Valley – Yolo
5-022.01 San Joaquin Valley – Easter San Joaquin
2-009.01 Santa Clara Valley – Niles Cone
3-001 Santa Cruz Mid-County
3-002.01 Corralitos – Pajaro Valley
3-002.02 Corralitos – Purisima Highlands
3-003.01 Gilroy-Hollister Valley – Llagas Area
3-004.01 Salinas Valley - 180/400 Foot Aquifer
3-004.06 Salinas Valley – Paso Robles Area
3-004.08 Salinas Valley – Seaside
3-004.10 Salinas Valley – Monterey
3-004.11 Salina Valley – Atascadero Area
3-027 Santa Margarita
5-022.05 San Joaquin Valley – Chowchilla
5-022.06 San Joaquin Valley – Madera
5-022.07 San Joaquin Valley – Delta-Mendota
5-022.08 San Joaquin Valley – Kings
5-022.09 San Joaquin Valley – Westside
5-022.10 San Joaquin Valley – Pleasant Valley
5-022.12 San Joaquin Valley – Tulare Lake
5-022.13 San Joaquin Valley – Tule
5-022.14 San Joaquin Valley – Kern
5-022.17 San Joaquin Valley – Kettleman Plain
5-022.18 San Joaquin Valley – White Wolf
3-014 San Antonio Creek Valley
3-053 Foothill
4-002 Ojai Valley
4-003.01 Ventura River Valley – Upper Ventura River
4-004.02 Santa Clara River Valley – Oxnard
4-004.07 Santa Clara River Valley – Santa Clara River Valley East
4-006 Pleasant Valley
4-008 Las Posas Valley
6-012.01 Owens Valley
6-012.02 Owens Valley – Fish Slough
7-024.01 Borrego Valley – Borrego Springs
7-024.02 Borrego Valley – Ocotillo Wells
8-001 Coastal Plain of Orange County
8-002.01 Upper Santa Ana Valley – Chino
8-002.03 Upper Santa Ana Valley – Riverside-Arlington
8-002.04 Upper Santa Ana Valley – Rialto-Colton
8-002.06 Upper Santa Ana Valley – Bunker Hill
8-002.07 Upper Santa Ana Valley – Yucaipa
8-004.01 Elsinore – Elsinore Valley
8-004.02 Elsinore – Bedford-Coldwater
8-005 San Jacinto
9-007 San Luis Rey Valley
9-033 Coastal Plain of San Diego