Environmental security

Why California’s droughts and floods will only get worse

The Golden State’s had a harsh winter. Between October 1 and March 3, most California weather stations across the state were reporting greater-than-normal amounts of precipitation. And the state’s snowpack has grown to be the fifth largest in 40 years, with up to 25 feet of powder in some places.

It’s needed moisture after a six-year-long drought from 2011 to 2017 and last year’s dry winter. Snowpack and reservoirs are stocked right now. But persistent rain has flooded many areas, including towns along Northern California’s Russian River. In Guerneville, residents paddled around after the river swelled to 45 feet high. Rain, floods, and mudslides have also wrecked homes and roads in areas across the state.

The dramatic shift from dry to wet this winter hints at what’s to come. Scientists predict that California’s total precipitation will remain close to constant in the future, but it will fall in a shorter window of time, with more of it as rain. The state will also experience greater variability—more very wet and more very dry years. These findings highlight the need to capture rainfall and improve aging infrastructure.