State water managers say California's springtime snowpack is nearly double its normal levels following five years of historic drought.
They say all the snow is beginning to melt, increasing the risk of flooding for communities downstream.
The California Department of Water Resources on Monday conducted its final snowpack survey of the state's wet season. The snow holds more water than compared to several past years.
The measurement comes well into spring, when the weather warms and snow melts, rushing downhill into canals and reservoirs.
Forecasters with the National Oceanic and Atmospheric Administration expect the Merced River in Yosemite National Park to go about a foot over its banks on Wednesday.
The mountain snow provides roughly a third of California's water supplies.