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The Dry Garden: Diverting winter rains from the streets to our flower beds

November 11, 2009 |  6:30 am


It stands to reason that some of the most progressive environmentalists in Los Angeles work for the Department of Public Works’ Bureau of Sanitation. They are the front line between what we discard and the environment.

Last week we looked at their fight to triage our system for recycling food scraps. This week the subject is their battle to capture rainfall before it enters L.A.’s massive storm drain system.

The bureau, along with a leading Southland water agency, the state Legislature and environmental nonprofit groups such as TreePeople and the Green LA Coalition are all moving to make harvesting rainwater as routine as recycling.

Rain shouldn’t be a pollutant, but as the Los Angeles Basin was steadily developed during the last century, the fields and meadows where the water used to infiltrate into the aquifer was steadily paved. 

So, when it rained, it flooded. By the 1930s the U.S. Army Corps of Engineers began building what is now 1,500 miles of pipes and 100 miles of open channels to catch the water that flowed from our roofs and driveways into the streets and storm drains. This runoff was then fed into the Los Angeles River and Ballona Creek.

To channel that water better, the river and creek also were paved.

The result: On dry days, the Bureau of Sanitation reckons that 100 million gallons of runoff from sprinklers, car washing and the like fall untreated into the Pacific Ocean.

When it rains, that figure skyrockets to more like 10 billion gallons with each one-inch shower. When a typical rain year is over, 120 billion gallons, or enough water to serve a million households a year, will have swept through Greater L.A.’s streets into the Pacific.

Were it fresh water that we were discharging, it would be merely wasteful. But the minute that rain leaves our gutters, downspouts and driveways for the street, it begins picking up motor oil, candy wrappers, dog feces and cigarette butts. By the time it reaches the ocean, fresh rainfall is toxic crud.

Capturing rain is by no means simple, but a sea change in attitude has taken place. As L.A. Board of Public Works Commissioner Paula Daniels likes to say, whereas the 20st century goal was to get rid of water as fast as possible, the challenge of the 21st century is to keep it.


The chronology bears this out. In 2004, Los Angeles voters passed Proposition O, a $500-million bond to clean up the city’s water courses. The screens that began appearing over storm drain openings were part of that initiative. To follow what it’s doing, click here.

Among local water authorities, the Inland Empire Utilities Agency is leading the charge to capture, treat and use storm water as part of its overall water supply.

Among cities, it is no surprise that the ones downstream have led the way. Santa Monica has long required new or significantly remodeled buildings to have rain-capturing percolation pits. This year it began experimental programs capturing street runoff.

Santa Monica’s frustration with the running gutters of its giant neighbor upstream may lessen soon.

“We hope to have a new low-impact development ordinance to the City Council in January,” Los Angeles’ Watershed Protection Program analyst, Joyce Amaro, says. “It’s maybe a little ambitious, but that’s the goal.”

This ordinance will apply to new buildings. But it does not take a construction program to act. For the great mass of us in existing houses, it has never been easier to find out what we can do. Virtually every city in Los Angeles County has a storm water outreach officer. Last month, Los Angeles even expanded its outreach to Facebook with a page for fans of storm water. Free trinkets such as totes and T-shirts are offered, but the eco-dog stuff is no joke. It’s all about poop-scooping.

BallonaCreek To capture rain from private homes, Los Angeles has just concluded a trial giveaway of 600 rain barrels in the Ballona Creek area. Most of the big hardware stores also carry them for about $100.

But another effective measure costs less than $10: Simply attaching downspout diverters to redirect rain from driveways and paved surfaces to garden beds. TreePeople has how-to guides for every kind of installation, from large cistern installations to simple gutter pipe attachments. The group also has a number of demonstration gardens.

In Orange County, a new rain garden with a 4,000-gallon underground cistern just opened at the Shipley Nature Center. This not only captures rain but recirculates it as a stream for wildlife. Friends of Shipley ambassador Stephen Engel invites anyone interested for a tour. He says the idea could be adopted to a private garden for a couple of thousand dollars.

The momentum to standardize rainwater capture statewide is also building. In October, as Gov. Arnold Schwarzenegger vetoed hundreds of bills in a battle with the Legislature over water and prison policy, one of the bills the he did sign was the Stormwater Resources Planning Act.

Unlike Proposition O, it does not bring new money to the effort to capture storm water. But it is designed to improve investment of existing public funds and to rationalize the patchwork of programs across the Southland into a more coherent policy.

It is the first bill that TreePeople has sponsored since its formation in the 1973. When asked why, TreePeople’s urban systems group manager Deborah Weinstein answered simply: “We want to see a rain barrel become as common as a recycling bin.”

-- Emily Green

Green's column on drought-tolerant gardening appears here weekly. She also blogs on water issues at www.chanceofrain.com.

Photos, from top: Raindrops accumulate on a spider web; an egret cruises Ballona Creek. Credits, from top: Ricardo DeAratanha / Los Angeles Times; Luis Sinco / Los Angeles Times