LOS ANGELES (AP) — As Californians tally the damage from recent storms, some are taking stock of the stormwater collected from cisterns, sumps, wells and underground basins — many built in recent years to provide relief to a state that has been locked in decades of drought.
The collected rainwater is a rare bright spot of downpours that have killed at least 20 people, crumbled hillsides and damaged thousands of homes.
Los Angeles County, which has 88 cities and 10 million residents, collected enough water from the storms to provide water for about 800,000 people for a year, said Mark Pestrella, director of the Los Angeles County Public Works Department.
In the four years since Californians passed a measure to invest hundreds of millions of dollars each year in building small and medium infrastructure projects that harvest stormwater, progress has been gradual, but not insignificant, experts say.
In Santa Monica, a new water project has captured nearly 2 million gallons (7,600 cubic meters) of runoff that, once treated, is used for plumbing, irrigation or pumped back into the city’s aquifer.
Sunny Wang, the city’s water manager, said the project will eventually save an average of about 40 million gallons (151,000 cubic meters) per year.
The vast majority of rainwater in California’s cities eventually drains into the ocean. In Los Angeles, a complex system of dams and paved flood channels directs water away from roads and buildings and out to sea as quickly as possible. The age-old infrastructure is designed to prevent urban flooding.
The concrete-lined Los Angeles River alone, which begins in the San Fernando Valley and ends in the ocean in Long Beach, sent 18,000 acres of rainwater out to sea during the recent storms, said Kerjon Lee, a Los Angeles spokesman. River. Angeles County Department of Public Works. That’s about 20% of Nevada’s allotment to the Colorado River each year.
“It’s a large number that we’re capturing, but it’s a small percentage of the watershed,” Wang said. “Billions of gallons of rainwater enter the Santa Monica Bay every year, so 40 million sounds like a lot, but it’s just a first step toward more investment we need to make.”
Santa Monica says the 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 simultaneously filters and treats sewage and runoff to produce water that exceeds state and federal drinking water regulations.
County officials say the water saved matters — not only to strengthen the water supply, but also to prevent pollutants picked up by rainwater from flowing into the Pacific Ocean.
Pestrella, the county’s public works chief, said stormwater collected in recent weeks could be enough to prevent Southern California’s Metropolitan Water District, which supplies major population centers such as Los Angeles and San Diego, from flooding next spring. imposes the strictest water restrictions. and summer.
To escape the drought, Pestrella added, “we need at least three years of this kind of rain.”
Most of Los Angeles’ water does not come from its own watershed, but from a massive storage and delivery system that transports snowmelt from Northern California’s Sierra Nevada Mountains and the Colorado River to the east.
County officials say the government has invested $400 million from the nationwide effort to increase local water supplies through stormwater harvesting in more than 100 regional projects, most of them new, in the past two years. Officials expect the projects in Southern California to be completed within eight years and said they could provide enough water for an additional 500,000 people in Los Angeles County.
The county’s long-term goal — over the next 30 years — is to collect 300,000 acre-feet of collected stormwater, or enough to serve up to 900,000 households annually.
Bruce Reznik, executive director of the nonprofit environmental organization Los Angeles Waterkeeper, called scaling up stormwater harvesting projects in Los Angeles “a race against time,” due to the state’s drought and overstretched water resources. He said a slow permitting process is partly to blame.
“We’re starting to make progress, but we clearly need to do better,” Reznik said. “People have become more and more serious in recent years.”
Earvin “Magic” Johnson Park is located in the Willowbrook area of South Los Angeles on a former oil storage field that was later partially developed into a housing project. Now, the 104-acre park with two lakes, a playground, exercise equipment, and community center also collect storm runoff.
The renovation was completed in 2021. For most people walking around the lakes, the park is just a nice place to walk. Ducks circle the lake in pairs while Canadian geese honk from a small island.
“It’s safe, fairly peaceful, and it’s just beautiful,” said Barbara Washington Prudhomme, a retired mail carrier.
She was unaware of the park’s other benefits — that a small building near the lake recycled nasty rainwater collected from storm drains that would have flowed out to sea and used it to fill the lake or irrigate the grass when needed.
When she was told about the park’s design, which allows it to collect and discharge up to 4 million gallons (about 15,000 cubic meters) per storm, she was impressed.
“That’s a good system when it works,” she said.
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Naishadham reported from Washington, DC
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