Pacific Swell

Southern California environment news and trends

Drought boosts interest in stormwater capture and reuse in LA

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A week after it was proposed, a nearly $700 million package of drought relief measures passed the state legislature Thursday and is on its way to Gov. Jerry Brown. A huge chunk of the money in the bill is earmarked for new projects to capture and store water from storms like those hitting California now.

So it’s worth pointing out what Southern California has done and has yet to do when it comes to managing stormwater.

Regional stormwater systems must meet certain federal Clean Water Act standards to operate. “Both permits create extremely strong opportunities to encourage stormwater capture to increase water supplies,” says Noah Garrison, a lawyer with the Natural Resources Defense Council.

“Urban pollution flows to storm drains and then is dumped into local waterways, tainting rivers and beaches with metals, nutrients, ammonia, bacteria, toxins, and pesticides,” writes Garrison, in a report entitled Rooftops to Rivers.

In the greater L.A. region, these rules require “new development and significant redevelopment, and in some circumstances existing development, to use green infrastructure practices” to control rainstorms of three-quarters of an inch or more.

The City of Los Angeles has also developed its own ordinance promoting stormwater capture. In recent years,  L.A. City Public Works, the L.A. Department of Water and Power, and the county flood control district and other local agencies have worked together to demonstrate how retrofitting concrete-and-asphalt city landscapes can save and clean up water.

In Panorama City, The River Project’s Melanie Winter admires the way the storm has filled swales dug into a formerly-concrete Woodman Avenue median. The River Project, the Department of Water and Power, and the L.A. Department of Public Work Bureau of Sanitation developed the project as part of a watershed plan for the Tujunga-Pacoima area.

Along the swales, a dirt walking path is framed with 27,000 square-feet of native and drought tolerant landscape and 99 new street trees. This is storm water capture in action. ​
 
“There’s 120 acres of this adjacent neighborhood that drains to this median. It would have otherwise gone to gutters and storm drains along the way.”
 
Water that otherwise would have been polluted runoff now stays here, replenishing the local groundwater. It nurtures trees and vegetation that act as lungs for the city and offer food to animals and bees that spread pollen. People have started using the new path as a running trail.​ Where concrete median compounded the urban heat island effect, the dirt path reduces it. 

Winter says this kind of low-impact development makes the city healthier. She calls it urban acupuncture.
 
“Urban acupuncture is little strategic interventions that in aggregate can make a massive difference here in los angeles.”

Another needle in the chi of Los Angeles is not far away in Sun Valley. The Elmer Avenue Green Street absorbs runoff from 37 acres of foothills, as it flows through a catch basin into infiltration galleries dug under the street itself.

Council for Watershed Health Senior Scientist Kristie Morris regularly tests water quality in the system. Thursday she was there to get a base line to compare with samples after this weekend’s storm.

“We’ve got a 4-inch storm apparently moving through, through Sunday so we hope to quantify the amount of water we’re capturing from that and look at the water quality benefits as well,” she says. Elmer Avenue captured 59 acre-feet of water in a recent year, she said – that’s equivalent to the amount of water 2 to 3 average households use a year.

 

These projects are among dozens of similar efforts around L.A. According to the LA Department of Public Works Bureau of Sanitation, together they can capture at least 20-thousand acre feet of water a year. You could fill a Rose Bowl 77 times with that.
 

It's ​unclear what money the city will get from the drought relief package to create more projects like these. But Adel Hagekhalil, with the Bureau of Sanitation can name a few  places he’d like it to go.

At the top of the list is a 46-acre gravel pit in Sun Valley that he sees being transformed into a wetland park. The Strathern Wetlands Park is a collaboration between the Los Angeles County Flood Control District, the City of Los Angeles, and the Sun Valley Stakeholders Group. 
 
“I think we’ve done some great things for limited funding, there’s more that can be done,” he says.
 
Hagekhalil says the new drought legislation is a good signal from Sacramento that protecting and enhancing local water supplies is important.

“I’m glad that there’s a lot of heightened recognition about the challenges we’re facing,” he says. “Challenges bring opportunity.”

Hagekhalil says rain, too, is an opportunity – and he’s glad L.A.'s stormwater capture projects are actually seeing runoff to capture during this relatively dry season.

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