Lake Oroville, Malibu's main water source, is 99% full Play

California's largest water reservoir — the one that supplies Malibu with most of our water — is 99 percent full this year.

Lake Oroville is the state's second-largest reservoir and a key component of California's water system. The massive reservoir sits behind America's tallest dam 450 miles north of Malibu, at the head end of a system of rivers, canals and pipes that supply 27 million Californians with most of their water.

And the full reservoir comes in a water year where practically no snow fell. Lake Oroville is still slowly rising, with just two feet to go to fill entirely.

When Oroville is full, it's a good year for water supplies. When it's low, water restrictions are a near certainty.

Only three years ago, Lake Oroville was in terrible shape — just 22 percent full. There had been three years of drought in northern California.

But now, four years of heavy winter rains — rain but no snow.

Oroville Dam is 770 feet high, taller than the Washington Monument.