San Antonio Creek Water Availability Active
Located in Santa Barbara County, California, the San Antonio Creek Groundwater Basin is a rural agricultural area that is reliant on local water supplies, predominantly groundwater. Because of the growth of irrigated agriculture in the area, water demands have increased significantly, taxing local groundwater supplies. Groundwater resources are also used to supply local inhabitants, as well as parts of Vandenberg Air Force Base (VAFB).
Santa Barbara County, VAFB, and the U.S. Geological Survey are working together to better understand the water resources and demands in the San Antonio Creek Groundwater Basin. The cooperative study, referred to as the San Antonio Creek Groundwater Availability Project, seeks to help stakeholders plan for future water use by providing data that will help assess the quantity and quality of the area’s water supply, and by establishing tools to allow stakeholders to effectively utilize the available water resources.
Surface-Water Monitoring
Historical water budgets for the San Antonio Creek Valley have indicated that infiltration from streamflow during ephemeral winter runoff events is a major source of recharge to the groundwater system (Martin, 1984). Similarly, groundwater discharge to Barka Slough is the major natural discharge from the basin and is critical for maintaining riparian wetland habitat supporting endangered species. For these reasons, as part of a comprehensive hydrologic investigation, it is important to make field measurements that can be used to determine independent estimates surface water movement throughout the basin and estimates of groundwater/surface water interactions.
Groundwater Monitoring
Groundwater is the main source of water in the San Antonio Creek Valley. Demand for groundwater in the predominantly rural valley has increased significantly because of the establishment of extensive irrigated agriculture on formerly non-irrigated land. Groundwater withdrawals have resulted in measured water-level declines ranging from 35 to more than 100 feet since the 1950s. There is concern by many stakeholders that continued water-level declines may have negative impacts on groundwater supply. To plan for future use, it will be important to evaluate the quantity and quality of the groundwater in the valley and establish tools to allow stakeholders to make informed management decisions.
Water Chemistry
Historical water-chemistry data will be used in conjunction with data collected as part of this study. Water chemistry samples will be collected from monitoring wells installed as part of this study, including two multiple-well monitoring sites (monitoring different depths in the aquifer) and eight shallow monitoring wells. Samples will also be collected from about 15 existing wells (locations to be determined). These samples will be analyzed for chemical and isotopic constituents to help evaluate the regional source(s), flowpath(s), and age(s) of water from wells. This information will be used to help characterize the groundwater-flow system and document differences in water chemistry, both areally and vertically within the basin.
Interactive Map
In order to understand the integrated hydrologic system, many different types of data are being gathered from both the surface water and groundwater system. Learn about these data types and explore them with the interactive map.
Geologic & Hydrologic Models
An integrated hydrologic model will be developed as part of this study to more accurately assess and simulate the integrated surface water and groundwater system in San Antonio Creek Valley. The analysis of this integrated system will be done by refining the geohydrologic framework of the valley, as well as developing new recharge and hydrologic models.
Below are publications associated with the San Antonio Creek Valley.
Simulation of groundwater and surface-water resources of the San Antonio Creek Valley watershed, Santa Barbara County, California
Hydrogeologic characterization of the San Antonio Creek Valley watershed, Santa Barbara County, California
Groundwater quality in the South Coast Range Coastal groundwater basins, California
Status and understanding of groundwater quality in the South Coast Range-Coastal study unit, 2008: California GAMA Priority Basin Project
Digital tabulation of stratigraphic data from oil and gas wells in the Santa Maria Basin and surrounding areas, central California coast
Groundwater-quality data in the South Coast Range-Coastal study unit, 2008: Results from the California GAMA Program
Development and calibration of a two-dimensional digital model for the analysis of the ground-water flow system in the San Antonio Creek Valley, Santa Barbara County, California
Appraisal of ground-water resources in the San Antonio Creek Valley, Santa Barbara County, California
Geology and ground water of San Antonio Creek Valley, Santa Barbara County, California
Below are partners associated with this project.
- Overview
Located in Santa Barbara County, California, the San Antonio Creek Groundwater Basin is a rural agricultural area that is reliant on local water supplies, predominantly groundwater. Because of the growth of irrigated agriculture in the area, water demands have increased significantly, taxing local groundwater supplies. Groundwater resources are also used to supply local inhabitants, as well as parts of Vandenberg Air Force Base (VAFB).
Santa Barbara County, VAFB, and the U.S. Geological Survey are working together to better understand the water resources and demands in the San Antonio Creek Groundwater Basin. The cooperative study, referred to as the San Antonio Creek Groundwater Availability Project, seeks to help stakeholders plan for future water use by providing data that will help assess the quantity and quality of the area’s water supply, and by establishing tools to allow stakeholders to effectively utilize the available water resources.
Surface-Water Monitoring
Historical water budgets for the San Antonio Creek Valley have indicated that infiltration from streamflow during ephemeral winter runoff events is a major source of recharge to the groundwater system (Martin, 1984). Similarly, groundwater discharge to Barka Slough is the major natural discharge from the basin and is critical for maintaining riparian wetland habitat supporting endangered species. For these reasons, as part of a comprehensive hydrologic investigation, it is important to make field measurements that can be used to determine independent estimates surface water movement throughout the basin and estimates of groundwater/surface water interactions.
Groundwater Monitoring
Groundwater is the main source of water in the San Antonio Creek Valley. Demand for groundwater in the predominantly rural valley has increased significantly because of the establishment of extensive irrigated agriculture on formerly non-irrigated land. Groundwater withdrawals have resulted in measured water-level declines ranging from 35 to more than 100 feet since the 1950s. There is concern by many stakeholders that continued water-level declines may have negative impacts on groundwater supply. To plan for future use, it will be important to evaluate the quantity and quality of the groundwater in the valley and establish tools to allow stakeholders to make informed management decisions.
Water Chemistry
Historical water-chemistry data will be used in conjunction with data collected as part of this study. Water chemistry samples will be collected from monitoring wells installed as part of this study, including two multiple-well monitoring sites (monitoring different depths in the aquifer) and eight shallow monitoring wells. Samples will also be collected from about 15 existing wells (locations to be determined). These samples will be analyzed for chemical and isotopic constituents to help evaluate the regional source(s), flowpath(s), and age(s) of water from wells. This information will be used to help characterize the groundwater-flow system and document differences in water chemistry, both areally and vertically within the basin.
Interactive Map
In order to understand the integrated hydrologic system, many different types of data are being gathered from both the surface water and groundwater system. Learn about these data types and explore them with the interactive map.
Geologic & Hydrologic Models
An integrated hydrologic model will be developed as part of this study to more accurately assess and simulate the integrated surface water and groundwater system in San Antonio Creek Valley. The analysis of this integrated system will be done by refining the geohydrologic framework of the valley, as well as developing new recharge and hydrologic models.
- Publications
Below are publications associated with the San Antonio Creek Valley.
Simulation of groundwater and surface-water resources of the San Antonio Creek Valley watershed, Santa Barbara County, California
In the San Antonio Creek Valley watershed (SACVW), western Santa Barbara County, California, groundwater is the primary source of water for agricultural irrigation, the town of Los Alamos, and supplemental water to Vandenberg Space Force Base (VSFB). Groundwater pumpage has increased since the 1970s as non-irrigated agricultural land has been converted to irrigated land and as local pumping for muAuthorsLinda R. Woolfenden, John A. Engott, Joshua Larsen, Geoffrey CromwellHydrogeologic characterization of the San Antonio Creek Valley watershed, Santa Barbara County, California
The San Antonio Creek Valley watershed (SACVW) is located in western Santa Barbara County, about 15 miles south of Santa Maria and 55 miles north of Santa Barbara, California. The SACVW is about 135 square miles and encompasses the San Antonio Creek Valley groundwater basin; the SACVW is separated from adjacent groundwater basins by the Casmalia and Solomon Hills to the north, and the Purisima HilAuthorsGeoffrey Cromwell, Donald S. Sweetkind, Jill N. Densmore, John A. Engott, Whitney A. Seymour, Joshua Larsen, Christopher P. Ely, Christina L. Stamos, Claudia C. FauntGroundwater quality in the South Coast Range Coastal groundwater basins, California
Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project (PBP) of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality informationAuthorsCarmen A. Burton, Kenneth BelitzStatus and understanding of groundwater quality in the South Coast Range-Coastal study unit, 2008: California GAMA Priority Basin Project
Groundwater quality in the South Coast Range–Coastal (SCRC) study unit was investigated from May through November 2008 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in the Southern Coast Range hydrologic province and includes parts of Santa Barbara and San Luis Obispo Counties. The GAMA Priority Basin Project isAuthorsCarmen A. Burton, Michael Land, Kenneth BelitzDigital tabulation of stratigraphic data from oil and gas wells in the Santa Maria Basin and surrounding areas, central California coast
Stratigraphic information from 694 oil and gas exploration wells from the onshore Santa Maria basin and surrounding areas are herein compiled in digital form from reports that were released originally in paper form. The Santa Maria basin is located within the southwesternmost part of the Coast Ranges and north of the western Transverse Ranges on the central California coast. Knowledge of the locatAuthorsDonald S. Sweetkind, Marilyn E. Tennyson, Victoria E. Langenheim, Lauren E. ShumakerGroundwater-quality data in the South Coast Range-Coastal study unit, 2008: Results from the California GAMA Program
Groundwater quality in the approximately 766-square-mile South Coast Range–Coastal (SCRC) study unit was investigated from May to December 2008, as part of the Priority Basins Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basins Project was developed in response to legislative mandates (Supplemental Report of the 1999 Budget Act 1999-00 Fiscal Year;AuthorsTimothy M. Mathany, Carmen A. Burton, Michael Land, Kenneth BelitzDevelopment and calibration of a two-dimensional digital model for the analysis of the ground-water flow system in the San Antonio Creek Valley, Santa Barbara County, California
A two-dimensional finite-difference model was used to simulate ground-water flow conditions in San Antonio Creek valley. The model was calibrated to simulate steady-state conditions as approximated by ground-water conditions in 1943 and transient conditions during the period 1944-77. The transmissivity of the aquifer and the vertical hydraulic conductivity of the confining bed underlying Barka SloAuthorsPeter MartinAppraisal of ground-water resources in the San Antonio Creek Valley, Santa Barbara County, California
A nearly threefold increase in demand for water in the 154-square-mile San Antonio Creek valley in California during the period 1958-77 has increased the potential for overdraft on the ground-water basin. The hydrologic budget for this period showed a perennial yield of about 9,800 acre-feet per year and an annual ground-water discharge of about 11,400 acre-feet per year, comprising net pumpage ofAuthorsC. B. HutchinsonGeology and ground water of San Antonio Creek Valley, Santa Barbara County, California
No abstract available.AuthorsK. S. Muir - Partners
Below are partners associated with this project.