Paul Devereux is the General Manager at Reclamation District 1000, which manages the levees in Natomas. He says the snowpack in the mountains is about 175% of average, and all that water is going to have to come through Sacramento Valley reservoirs and waterways sooner or later.
"If we either have a very warm storm that comes in April or May or we spike to unusually high temperatures early in the season then it's going to come down too quickly and obviously the operators of the reservoirs will have to be releasing water to make space for that runoff coming in," Devereux said.
Devereux says an early snowmelt shouldn't cause flooding in
the Sacramento Valley, but may overwhelm waterways farther
south. The San Joaquin Valley's waterways have one-tenth of
Sacramento's water capacity, and the levees are made mostly of
sand.
Maurice Roos is Chief Hydrologist with the Department of Water
Resources. He says in a rainy year, when the reservoirs are full, a
late snowmelt is preferable.
"It's more manageable because you also have irrigation
demands," Roos said. "So some of the water will be
used. It also gives more time to evacuate space if we need
more space in the reservoirs."
Roos says some of the surplus water from an early snowmelt
will be used for irrigation, but most of it will flow into the
ocean and be lost.