Rain impact on California's mega reservoirs

LAFAYETTE, Calif. - The backbones of California's water supply are the six mega reservoirs: Shasta, Oroville, Trinity, New Melones, Don Pedro and San Luis.

Back on November eighth, the state's six biggest mega reservoirs were 33% full.

In normal years they would have been 54% full, but the drought kept them low. Seven weeks later, midnight December 30th, they were up to 34% full.

As of midnight December 31st, the atmospheric river added another percent, up to 35 percent. That's an enormous gain, but still well below where they should be. 

That means that our largest dams remain 65% empty requiring many more storms to get to normal levels.

ALSO: San Francisco sees mudslides, flooded homes

"It's gonna take a lot more than this to get us out of the hole we've dug ourselves," said California State Climatologist Dr. Mike Anderson.

Water agencies, such as the South Bay's Valley Water know that, as important as local rains are, they count heavily on those mega resevoirs.

"We're way, way, way, way, way below normal for what we should be seeing this time of year," said Valley Water Spokesman Matt Keller.

ALSO: South Bay reservoir in jeopardy of flooding

At 30% full, Lake Sonoma picked up one percent overnight but would need to double that to be at normal levels.

East Bay MUD's Comanche Reservoir, at 59% full, is at normal level.

Folsom Reservoir, at 57% od actually 140% of normal, a very good sign for this snowpack fed reservoir.