In order to gain a better understanding of recharge projects in California and its role in groundwater management, Water in the West researchers obtained all available grant applications that were submitted to DWR for the four recharge-related grant programs listed above. This new study evaluated more than 100 grant applications filed over the past 14 years. The applications were all for funding that would go either partly or entirely to recharge projects.
Based on the grant applications obtained by Water in the West, the anticipated annual recharge capacity of funded projects is 306,727 acre-feet per year. However, if we consider both the awarded and declined recharge applications studied, the recharge potential is closer to 785,000 acre-feet per year.
Both the higher and lower numbers are likely to be underestimates since only 30% of the Proposition 13 applications considered by DWR were available for analysis (57 out of 190).
Out of 136 recharge-related grant applications reviewed by Water in the West, 78 were awarded.
The 78 awarded projects we studied were awarded at different funding levels. This map shows all grant proposals sized by their requested budget and shaded by granted percentages, including unfunded applications (0%). The number of unfunded and partially funded applications is evidence of unfulfilled need for recharge across the state.
Funded projects were concentrated in the Central Valley and in southern California – areas with groundwater basins that have been identified by the Department of Water Resources as higher priority and having a greater need.
The overlap of recharge projects with overdrafted groundwater basins suggests that there is capacity for recharge in many areas and there is interest in using recharge as a tool to address local needs and concerns.
There was considerable diversity in the purpose of the recharge-related projects submitted for grant funding. Some recharge projects would help replenish local groundwater supplies during wet years, so that it can be utilized during dry periods (i.e. conjunctive use and/or groundwater banking) while others would help mitigate land subsidence.
Some projects requested funding to buy and regrade land for recharge ponds. Others wanted to establish a groundwater bank. Some projects appeared to frame recharge as an ancillary benefit to maintenance work like dredging silt from reservoirs.