Storms feed systems set up to capture rainwater

LOS ANGELES (AP) — As Californians tally the damage from recent storms, some are taking stock of the rainwater captured by cisterns, catches, wells and underground basins — many built in recent years to provide relief to a state locked in decades of drought.

The banked rainwater is a rare bright spot from downpours that killed at least 20 people, crumbled hillsides and damaged thousands of homes.

Los Angeles County, which has 88 cities and 10 million people, collected enough water from the storms to supply roughly 800,000 people for a year, said Mark Pestrella, director of the Los Angeles County Public Works department.

In the four years since Californians approved a measure to invest hundreds of millions of dollars each year to build small and medium-sized infrastructure projects that collect rainwater, experts say progress has been gradual, but not insignificant.

In Santa Monica, a new water project captured nearly 2 million gallons of runoff that once treated gets used for plumbing, irrigation or pumped back into the city's aquifer.

Sunny Wang, water resources manager for the city, said the project will eventually save an average of about 40 million gallons per year.

The vast majority of rainwater in California's cities eventually flows into the ocean. In Los Angeles, a complex system of dams and paved flood control channels steer water away from roads and buildings and out to sea as fast as possible. The century-old infrastructure was designed to prevent urban flooding.

From the concrete-lined Los Angeles River alone, which starts in the San Fernando Valley and ends in the ocean in Long Beach, 58,000 acre-feet of stormwater was sent out to sea during the recent storms, said Kerjon Lee, spokesman for the Los Angeles County Department of Public Works. That's about 20% of Nevada's allotment from the Colorado River each year.

"It's a big number we're capturing, but it's a small percentage of the watershed," Wang said. "Billions of gallons of stormwater enter Santa Monica Bay each year, so 40 million sounds like a lot but it's just a first step towards more investments we need to make."

Santa Monica says its Sustainable Water Infrastructure Project is the first of its kind in California. Most people would hardly know it exists.

Hidden under a newly paved parking lot next to a county courthouse, the wastewater treatment plant filters and purifies sewage and runoff simultaneously to produce water that exceeds state and federal drinking water regulations.

County officials say the water being saved matters — not just to bolster water supplies but also to prevent contaminants picked up by rainwater from flowing into the Pacific Ocean.

Pestrella, the county's public works chief, said the stormwater captured over the past few weeks could be enough to prevent the Metropolitan Water District of Southern California, which supplies major population centers including Los Angeles and San Diego, from imposing the strictest water restrictions next spring and summer.

To escape the drought, Pestrella added, "we need at least three years of this kind of rain."

Most of Los Angeles' water isn't from its own watershed, but from a vast storage and delivery system that carries snowmelt from the Sierra Nevada range in Northern California and the Colorado River to the east.