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GREENING

Channeling the raindrops

April 13, 2006|Emily Green | Times Staff Writer

MY frontyard looked like a storybook American home -- a lavender-lined front walk, two oaks, grass paths, a driveway to the side -- but it was a textbook polluter. The gutter fed directly to the concrete driveway. This swept rain straight from the gutter, onto the driveway, into the street.

Rain, it turns out, is only pure until it hits the street. The minute it rolls off our properties, it becomes what engineers call storm water -- a toxic soup of water, pesticides, fertilizers, motor oil, cigarette butts, fast-food wrappers, batteries and dog droppings. During a rainy day, as much as 10 billion gallons of this urban concoction floods out of 65 outfalls into the Santa Monica and San Pedro bays, says Joyce Amaro from the City of Los Angeles Stormwater Program.It could not be a more complete perversion of the natural cycle, in which April showers feed lakes and springs, and are absorbed into the groundwater supply, or as the watery intelligentsia prefer, the aquifer.

I had been gardening in central Los Angeles and going swimming at Santa Monica beaches for six years before I made the connection. It was July 2004. I was standing before Garden/garden, a pair of test gardens that landscape designer Susanne Jett and City of Santa Monica Water Resources specialist Bob Galbreath had created to demonstrate the difference between a conventional frontyard with lawn, roses and concrete paving and a conservationist model with native plants and plumbed to capture rainfall. Jett began talking about something called "percolation pits," Galbreath about how keeping rain on the property could capture the water in its pure state, feed plants and help save our coastline. I took notes, nodded appreciatively, went home and put my head in my hands.

And so 2005 became the year of chasing rain. As Southern California received 37 inches of rainfall -- the second heaviest drenching in more than a century -- and more than 20,000 gallons of rainfall poured off the front pitch of my roof alone, I began digging trenches to direct the water from the downspout, away from the driveway in channels around flowerbeds. This captured some water but also created a mud channel, adding soil to the runoff. When the skies cleared, the network of trenches amounted to a snaking, tripping hazard.

I studied the layout of Garden/garden to see if I could adapt it to my home. Its methods were so efficient that in a winter month, Galbreath's and Jett's model garden used 1 gallon of water, the conventional one next to it 8,000. "Eight thousand to 1 isn't a bad ratio," said Galbreath.

But it wouldn't work for me: Its methods are perfect for unplanted sites but challenging for existing gardens with established trees. The water feeds through downspouts into submerged percolation pits. I had already planted oaks where the pits would theoretically go and their root zones would be badly damaged.

Other solutions recommended by the city of Santa Monica, the environmental group TreePeople and the Los Angeles storm water programs were interesting but not quite right either. Cisterns -- tanks by the downspouts -- were ugly, held only a fraction of what rolled off the roof, and I worried about mosquitoes. Basic advice to buy extensions for the drain pipes and redirect gutter water into planted areas was good and I used it in the backyard. Out front, however, the impromptu trenches were a mess.

One solution would have been to break up the driveway, creating a permeable quilt of broken stone. Or maybe the twin strips of concrete that garden designers call a "Hollywood drive"? No, the car could be moved to the street, the rainwater couldn't. The driveway had to go. While I was at it, the front walk could also be broken up into a water-permeable path of pavers.

This required a landscaper. I chose Nick Tan, a specialist in native landscapes at the Eagle Rock company Urban Organics. I know Nick and thought his work the perfect mix of groovy and profound. My commission: zero runoff, near zero irrigation. He suggested terracing built around a dry streambed that could fill, and then gradually absorb the water.

On the first day, Nick showed up with a friend, another landscaper, Marco Barrantes, who has a master's degree in planning from UC Berkeley and a unique flair for turning broken concrete into dry-stone terracing. They began by renting a jackhammer and a compressor so that it had the power to break but not shatter the concrete. They then sorted out reusable slabs of concrete from the rubble, and scraped up the latter to take to the dump. The viable pieces were laid out like a huge jigsaw puzzle so that they could be reused in dry-stone walls and new pathways.

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