LOS ANGELES -- California's wet winter has dumped at estimated 18 trillion gallons of rain in February alone. But much of it is simply going down the drain.
In what has become a source of much concern in a state prone to droughts and water shortages, the vast majority of rainwater in urban areas flows into storm drains and is eventually lost to the Pacific Ocean.
"When you look at the Los Angeles River being between 50 percent and 70 percent full during a storm, you realize that more water is running down the river into the ocean than what Los Angeles would use in close to a year," said Mark Gold, associate vice chancellor for environment and sustainability at the University of California, Los Angeles. "What a waste of water supply."
For Southern California, this is shaping up to be the wettest winter in years -- serving as a reminder of how much water is wasted when the skies open up.
Local agencies did step up water capture efforts after the region's most recent drought, but officials admit it's going to take time and a lot of money to save the significant amounts of rainwater now being lost.
Climatologist Bill Patzert estimates that more than 80 percent of the region's rainfall ends up diverted from urban areas in Southern California into the Pacific.
"All those trillions of gallons of rain, which sound so sweet, really end up in the ocean," he said. "There are some catchment basins, but it's been so dramatically dry for the past two decades that it's not filling them up. Roots and soil are sucking up the water and preventing it from getting to the groundwater basins."
The storms have significantly boosted the snowpack in the Sierra, which is a major source of California's water. As the snow melts, it's collected in a series of rivers, dams and reservoirs and sent to farms and cities.
Cities have been exploring what can be done to capture urban runoff.
Among the ideas being tried are slowly feeding rainwater underground, a process known as aquifer recharge, and creating more permeable surfaces where the water flows, such as removing some of the concrete around the Los Angeles River bed.