This week, the California Water Foundation released a study evaluating the potential benefits of recharging groundwater through the flooding of agricultural lands using excess winter river flows. Titled Creating an Opportunity: Groundwater Recharge through Winter Flooding of Agricultural Land in the San Joaquin Valley, the study is focused on a portion of the east side of the San Joaquin Valley in Merced, Madera, and Fresno counties.
While excess winter flows are not available every year, the study found an average of 80,000 to 130,000 acre-feet per year can be diverted through the existing available capacities in the diversion turn-outs, conveyance, and distribution for delivery to farms. Among other findings, the study found that the proposed recharge method would reduce overdraft by 12 – 20 percent.
The study also states that expansion of such an approach across a broader geographic area, including excess winter flows from other major watersheds in the valley, such as the San Joaquin, Tuolumne, and Stanislaus rivers, would provide a significant contribution towards addressing the estimated annual overdraft. The full study can be assessed here.