CA winter storms could spell flooding this spring

Written by Danielle Chiriguayo, produced by Marcelle Hutchins

A home covered with snow is located near Lake Tahoe, California, which has seen record levels of snow this winter, March 24, 2023. Photo by REUTERS/Fred Greaves.

After months of heavy storms, California’s mountains now have some of the largest snowpacks on record. It’s welcoming news for reservoirs statewide that remain below their historical average. But it’s also raising concern over how fast the snow could melt and the flooding that comes with it. 

“It’s a hell of a lot of snow,” says Jeffrey Mount, senior fellow at Public Policy Institute of California Water Policy Center. The snowpack currently sits at 237% of average, which is a water equivalent of 61 inches. There’s even enough snow on the eastern Sierra Nevadas that is more water than the southern coast uses in a year. 

Once the snow melts, some will flow down into the Tulare Basin in the Central Valley. Mount says the area, which dried up in recent years, typically refills once every generation after a period of intensive storms.  

“We had it in 1997. We had it in 1983. We had it in 1969. And we had it in 1952. They were big rebirths. Nature called its lake home in all those years simply because there's just no place to put the water in. There's so much water going into that hole in the ground.” 

But another area also has flood managers worried — the San Joaquin River, where snowmelt from the central Sierra Nevadas flows. 

“It's got pretty crummy levees along it, and a lot of poor communities are parked along it. So people are really worried that that snow melt, if it comes fast enough, is going to really cause some trouble there.” 

Now, Mount says there’s an increased urgency to beef up water management during wet years, focusing on groundwater.

“This doesn't mean we're building a bunch of dams throughout California, Our biggest empty reservoir is in the ground. And it's more than three times the space that we have in our dams. So we need to have strategies that put more water in the ground during these very wet years.” 



  • Jeffrey Mount - senior fellow at Public Policy Institute of California Water Policy Center; professor emeritus, Department of Earth and Planetary Sciences, UC Davis


Marisa Lagos