San Antonio Creek Valley
- Basin Name
- San Antonio Creek Valley
- Basin Number
- SGMA Basin Priority
- Critically Overdrafted
- Hydrologic Region Name
- Central Coast Hydrologic Region
- Santa Barbara
Located in California’s Central Coast hydrologic region, the San Antonio Creek Valley is 67,437 acres in size. This Medium priority basin is home to an estimated 2,168.00 people (2010 value), which have been at a rate of 24.53. San Antonio Creek Valley is a(n) basin with approximately 281 wells, of which approximately 9 are water supply wells. Groundwater accounts for approximately 97.60 percent of the basin’s water supply.
2014: CASGEM Basin Prioritization: high
Revised basin boundary description
2018: Basin prioritization: medium.Comments:
- Groundwater withdrawals have resulted in measured water-level declines ranging from 35 to more than 100 feet since the 1950s.” Source: USGS 1) The cause of the westward water quality degradation has been thought to be the accumulation of lower quality water from agricultural return flow and the dissolution of soluble minerals (Hutchinson, 1980). The highest TDS concentration (3,780 mg/l) was found in the extreme western end of the Valley and westward of the Barka Slough; the lowest concentration (263 mg/l) was found at the extreme eastern end. Analyses compiled for samples taken between 1958 and 1978 indicate that groundwater quality remained fairly stable during that period. Analyses of water sampled in 1993 for several wells show only slight increases since the previous study. There is evidence that poor quality connate waters exist within fracture zones of the bedrock and that this water might be induced into overlying strata, especially west of Barka Slough. There is no evidence of seawater intrusion in the basin, nor is the basin considered susceptible to seawater intrusion due to the consolidated rock that separates the basin from the ocean. Source: Santa Barbara County Groundwater Report 2011
2018 Final Basin Prioritization: Basin status remains unchanged at medium priority.