Welcome to the Kern County Subbasin Groundwater Sustainability Agencies’ Website.
Groundwater is a vital resource for our community’s health, economy, public safety, and future. Through collaboration, innovation, and science-based solutions, the Kern County Subbasin’s 20 Groundwater Sustainability Agencies (GSAs) are working together to ensure local compliance with the Sustainable Groundwater Management Act (SGMA) and safeguard this critical resource for current and future generations.
This website provides updates, access to important documents (like the Groundwater Sustainability Plans), and opportunities for public engagement. We invite you to explore our plans, attend meetings, and share your input as we collaborate toward a sustainable water future.
About the Kern County Subbasin
Location & Overview
The Kern County Subbasin (DWR Basin No. 5-022.14) is the largest groundwater subbasin in California, spanning approximately 2,834 square miles (1,782,321 acres). Located in the southern San Joaquin Valley Groundwater Basin and the Tulare Lake Hydrologic Region, it is entirely within Kern County (composing 34% of the County) and borders four neighboring subbasins:
- Tulare Lake Subbasin (North)
- Tule Subbasin (North)
- Kettleman Plain Subbasin (North)
- White Wolf Subbasin (South)
Sustainable Groundwater Management Act (SGMA) Compliance
Enacted in 2014, SGMA mandates sustainable groundwater management through local Groundwater Sustainability Agencies (GSAs). These agencies develop and implement Groundwater Sustainability Plans (GSPs) with key components, including:
✅ Sustainability Goals
✅ Hydrogeologic Conceptual Model (HCM)
✅ Water Budget Analysis
✅ Sustainable Management Criteria (SMCs)
✅ Monitoring Networks (groundwater levels, groundwater quality, subsidence, interconnected surface water)
✅ Projects & Management Actions (P/MAs)
✅ Stakeholder Engagement
Groundwater Sustainability Agencies (GSAs)
The 20 GSAs coordinating management in the Kern County Subbasin include the following:
| GSA | Website | GSA Map (PENDING) | GSP Coverage |
| Arvin GSA | https://aewsd.org/water/sgma/ | Kern Subbasin GSP | |
| Buena Vista GSA | https://bvh2o.com/ | Kern Subbasin GSP plus supplemental blue pages pertaining to conditions and characteristics unique to the GSA | |
| Cawelo Water District GSA | https://www.cawelowd.org/ | Kern Subbasin GSP | |
| Greenfield County Water District GSA | https://greenfieldwater.specialdistrict.org/ | Kern Subbasin GSP | |
| Henry Miller Water District GSA | https://www.wakc.com/whos-who/henry-miller-water-district/ | Kern Subbasin GSP plus supplemental blue pages pertaining to conditions and characteristics unique to the GSA | |
| Kern Non-Districted Land Authority GSA | https://kndla.org/ | Kern Subbasin GSP | |
| Kern River GSA | http://www.kernrivergsa.org/ | Kern Subbasin GSP | |
| Kern Water Bank GSA | https://www.kwb.org/ | Kern Subbasin GSP | |
| Kern-Tulare Water District GSA | https://kern-tulare.com/index.php/sgma | Kern Subbasin GSP plus supplemental blue pages pertaining to conditions and characteristics unique to the GSA | |
| North Kern Water Storage District GSA | https://www.northkernwsd.com/sustainable-groundwater-management-act/ | Kern Subbasin GSP | |
| Olcese Water District GSA | https://olcesewaterdistrict.org/sgma/ | Kern Subbasin GSP plus supplemental blue pages pertaining to conditions and characteristics unique to the GSA | |
| Pioneer GSA | https://www.kcwa.com/ | Kern Subbasin GSP | |
| Rosedale Rio-Bravo Water Storage District GSA | https://www.rrbwsd.com/ | Kern Subbasin GSP | |
| Semitropic Water Storage District GSA | https://apps.geiconsultants.com/semitropicgcp/ | Kern Subbasin GSP plus supplemental blue pages pertaining to conditions and characteristics unique to the GSA | |
| Shafter-Wasco Irrigation District GSA | https://www.swid.org/sgma/ | Kern Subbasin GSP | |
| Southern San Joaquin Municipal Utility District | https://www.ssjmud.org/ | Kern Subbasin GSP | |
| Tejon-Castac Water District GSA | https://www.tejoncastacwd.com/ | Kern Subbasin GSP | |
| West Kern Water District GSA | https://wkwd.org/ | Kern Subbasin GSP | |
| Westside District Water Authority GSA | https://www.westsidedwa.org/about-westside-district-water-authority-gsa | Kern Subbasin GSP plus supplemental blue pages pertaining to conditions and characteristics unique to the GSA | |
| Wheeler-Ridge Maricopa GSA | https://wrmwsd.com/ | Kern Subbasin GSP |
Land Use & Communities
The subbasin features a diverse mix of land uses, with agriculture, native and idle land, urban, suburban, and rural communities, and industrial oilfields covering the landscape. The largest population center is Bakersfield, a mid-sized city surrounded by unincorporated suburban areas. Smaller towns and rural communities are also scattered throughout the region.
Primary Land Use Breakdown
- Active Agriculture: 657,000 acres (36.2%)
- Native Land: 600,000 acres (33.1%)
- Idle Agriculture: 256,000 acres (14.1%)
- Urban, Suburban & Rural Communities: 149,000 acres (8.2%)
- Industrial Oil Fields: 91,000 acres (5.0%)
- Other Uses: 62,000 acres (3.4%)
A comprehensive, multisource dataset is maintained to track land use changes across the subbasin.
Water Sources & Management
The Kern County Subbasin relies on a combination of surface water, groundwater, and imported supplies to meet its water needs. Key features include:
- The Kern River, originating in the Sierra Nevada, is the primary natural surface water source.
- Imported water supplies makeup a critical water source, with many GSAs in the Kern County Subbasin having access to State Water Project or Central Valley Project surface water supplies.
- An extensive network of canals and conveyance systems distributes water for agricultural, municipal, and industrial use.
Historical Challenges & Modern Solutions
- Groundwater overdraft was first identified in the 1940s, leading to declining water levels.
- Local water districts were formed to secure Kern River rights and facilitate SWP (State Water Project) and CVP (Central Valley Project) contracts.
- Conjunctive use programs allow stored surface water from wet years to replenish groundwater supplies during droughts.
- Water banking, recovery, exchange projects, and use of recycled water optimize available resources.
Public Data & Transparency
The Kern Subbasin Data Management System provides open access to:
📊 Groundwater sustainability reports
📈 Real-time monitoring data (levels, quality, subsidence)
📑 GSP documents & compliance updates
