Upper Santa Ana Valley – Riverside-Arlington
- Basin Name
- Upper Santa Ana Valley – Riverside-Arlington
- Basin Number
- SGMA Basin Priority
- Very Low
- Critically Overdrafted
- Adjudicated Basin
- DWR Region & POC
DWR Southern Region Office
Watermaster: San Bernardino Valley Municipal Water District
Western Municipal Water District
- Number of Wells
- Hydrologic Region Name
- South Coast Hydrologic Region
- Riverside, San Bernardino
Located in California’s South Coast hydrologic region, the Upper Santa Ana Valley – Riverside-Arlington is 56,563 acres in size. This Very Low priority basin is home to an estimated 337,000 people (2010 value), which have been at a rate of 13.95. Upper Santa Ana Valley – Riverside-Arlington is a(n) basin with approximately 685 wells, of which approximately 38 are water supply wells. Groundwater accounts for approximately 76.92 percent of the basin’s water supply.
2014: CASGEM basin prioritization – high. Comment: Water quality degradation issues known in several public supply wells.
2016: Basin boundary modified along with boundaries of Yucaipa 8-002.07, Bunker Hill 8-002.06, Rialto-Colton 8-002.04 subbasins to align with adjudicated areas
2018: Draft basin priority – high. Comment: 1) CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR 2) Hydrographs of water levels at 3 selected wells, shown on Figures 2.7 and 2.8, demonstrate water level changes over time through different hydrologic conditions. Generally, these hydrographs show increasing water levels starting around 1960 and stabilizing or declining somewhat after the 1980s. Source: Arlington Basin Groundwater Management Plan, 2011
References: Santa Ana Watershed Project Authority
2018 Final Basin Prioritization: Basin priority changed from high to very low.