Did winter storms replenish California’s depleted groundwater supplies? Here’s what data shows.
Winter storms have filled California’s reservoirs and built up a colossal Sierra snowpack that’s nearly twice its normal size for this time of year. But years of dry conditions have created problems far beneath the Earth’s surface that aren’t as easily addressed. Groundwater — found in underground layers containing sand, soil and rock — is crucial for drinking water and sustaining farms. During drought years, 60% of California’s annual water supply comes from groundwater. … The chart below shows how water on the surface and underground have changed over the years in California’s Central Valley — an agricultural hub that has seen some of the state’s most pressing issues related to groundwater. Compared with 2004, the amount of water on and below the ground in 2022 has dropped by nearly 55 cubic kilometers.