Drought-ravaged L.A. looking to 'sponge up' every bit of rainwater

03/20/2015 04:39 EDT | Updated 05/20/2015 05:59 EDT
A tow truck lifts a trashed car off the street. A shopping cart lies abandoned in the alley.

This area of Los Angeles is what economists might call "economically disadvantaged." But one block in the heart of this struggling neighbourhood has gone through a $27-million retrofit.

Now, on this block, instead of channelling the rainwater run-off to the sea, the city is collecting it.

For a state that is in the midst of a massive three-year drought, and a city that has already begun water rationing, this is, almost literally, a godsend.

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In the past, every time it rained, says Nancy Steele, the city was wasting precious water it didn't even use.

The executive director of the Council for Watershed Health, Steele helped plan the Elmer Avenue Neighbourhood Retrofit, and she points to what looks like a normal storm drain.

"There's no bottom," she says, in the retrofitted one.

"A normal storm drain would be all concrete. It would direct the water into the storm drain system, which would take the water into, in our case, the L.A. River."

But this new, retrofit storm drain has no concrete bottom and so it allows the water to dribble and percolate.

"So that provides the storage underneath the street for the water to flow through and then slowly soak into the ground."

Another part of the retrofit are the shallow ditches near the sidewalk, called bioswales. They act as filters to clean the water before it re-enters the aquifer.

"It's basically just a dip in the property that allows the water to slow down and piddle and percolate," Steele says.

"The plants that are in the bioswale are not only climate-appropriate plants that do well here, but they also help keep the soil fertile. They enrich it, so the water can soak in."

Even the sidewalks themselves are permeable, allowing the water to pool underground instead of just running off into storm drains.

Steele says these methods capture just over 10 million U.S. gallons of water every year. 

"What that means is that there's enough water captured through the street to provide drinking water for about twice that many households," she says.

"So about 24 houses on this street could provide enough drinking water for 50 to 60 households each year."

Steele believes this concept would work not just in Los Angeles or across California, but in any of the growing number of cities around the world that are running out of water. 

"You can design these projects anywhere," she says. "They're eminently scaleable."

Raining money

Wing Tam of the Los Angeles Department of Public Works says there are a handful of similar projects scattered across the city.

He's hoping the $1-billion US drought emergency plan announced on Thursday by California Gov. Jerry Brown will allow them to build even more of these projects.

"We have probably over 100 of these green street projects standing by and ready to move forward as soon as the funding becomes available," Tam says.

So far, however, landscaping programs have had mixed success in L.A.

An incentive that pays people to replace their lawns with drought-friendly vegetation — cash for grass, it's been called — has only been used by about a tenth of one per cent of homeowners.

"Let's face it," says Chris Solek of the Council for Watershed Health, "people like green lawns, people like traditional landscaping and that is something that's very hard to change."

Steele's argument, however, is that if people won't change, then you have to change the city. In this case, from a giant umbrella to a sponge.