As of Wednesday, California’s two largest reservoirs, Shasta and Oroville, are more than 90% full, a significant reversal from the summer and fall of 2014, when the state was locked in severe drought. Folsom Lake is filled to about 86% capacity.

After four dry winters, storms have helped replenish these Northern California reservoirs with rain and runoff from the state’s relatively healthy snowpack. California’s complex water delivery system helps move the water from the northern part of the state, where most of the rain and snow falls, to the southern part of the state, where much of the population resides.