The October 2023 Semi-Annual Groundwater Conditions Update, from the Department of Water Resources (DWR) highlights how impactful the series of atmospheric rivers were during the Water Year 2023. Data collection through August 31, 2023, reveals a remarkable turnaround compared to 2022. Groundwater levels experienced notable improvement propelled by managed aquifer recharge and natural processes.
DWR estimates 3.8 million acre-feet of recharge capacity accumulated in Water Year 2023. Notably, over 1.2 million acre-feet resulted from permitted groundwater recharge by state agencies. Additional contributions came from floodwater recharge and various managed and natural sources. The Central Valley played a pivotal role, contributing to over 15 million acre-feet of groundwater pumping, constituting 90 percent of California’s total extractions. Extraction rates were particularly high in the Chowchilla, Kaweah, and Fillmore basins, with Kern County, Kings, and Kaweah basins extracting the greatest volumes.
While satellite data indicates a temporary decline in land subsidence rates, concern remains for future dry periods. Subsidence is anticipated to rise unless sustained efforts to reduce long-term groundwater extraction are implemented under ongoing sustainable groundwater management. The Tulare Lake Hydrologic Region experienced the most subsidence, covering approximately 2,400 square miles, followed by the San Joaquin River Region and the Sacramento River Region.
Despite fewer voluntary reports of dry domestic wells in 2023 compared to previous years, with 650 reported, the state still faces challenges. The installation of domestic and irrigation wells reached a nine-year low. Groundwater recharge projects played a central role during floods, diverting water away from vulnerable areas and replenishing groundwater basins. The focus now shifts to enhancing real-time groundwater monitoring infrastructure to fortify California’s resilience against future climatic extremes. More detailed insights will be available in the annual Groundwater Conditions Report in the spring of 2024.
Brian German
Ag News Director / AgNet West