Five years ago, environmentalist Andy Lipkis took a group of bureaucrats to a bungalow in South Los Angeles and faked a rainstorm.
As officials huddled under umbrellas, fire hoses bombarded the roof with hundreds of gallons of water in a matter of minutes. But instead of flowing into the street, every drop coming off the little house was caught and put to use.
A cistern connected to the roof collected enough moisture to help water the backyard for weeks. Hedges in the front absorbed water flowing toward the street, directing it back into the ground. A tiny metal grate captured the oil-tainted runoff that trickled down the driveway and deposited it in a tank that filtered it clean before releasing it into the earth.
It was just one bungalow in a city of thousands. But Lipkis, 48, head of the group TreePeople, argued that what his audience was witnessing could be done everywhere in Los Angeles -- not only to save water, but to prevent flooding and stop filthy runoff from polluting the ocean.
The officials were so impressed that they are now attempting to duplicate the feat on a larger scale -- catching and reusing rainfall in a 4.4-square-mile residential and industrial area of Sun Valley in the San Fernando Valley.
It won't be cheap, but Lipkis and a growing number of official converts believe the approach could turn out to be a major step toward two important goals -- conserving precious water in an arid metropolis and cleaning the region's beaches -- and in the process, challenging the odd logic of water use in the city.
To quench Los Angeles' legendary thirst, hugely expensive man-made rivers pipe in water from hundreds of miles away. Today, the city imports roughly 85% of its water. Yet to prevent flash floods, the city pays again to convert natural streams into concrete storm drains that shuttle the same precious fluid out of town as swiftly as possible when it rains.
With roughly 70% of Los Angeles covered by structures or pavement, such a large amount of motor oil, chemicals and waste washes down drains and out to sea that the city repeatedly violates the Clean Water Act. It is under a federal court order to stop the pollution soon, which could cost taxpayers tens of millions of dollars in cleanup fees if an alternative to mass treatment is not found.
For years, environmental activists have argued that a different approach to how the city handles rainwater could accomplish those cleanup goals at a far lower price and produce drinking water at the same time. With the Sun Valley project, they will get a chance to see if their theories actually work.
"It's a very important project, not only for Southern California, but for the entire country," said David Beckman, a senior attorney with the Natural Resources Defense Council.
Lipkis' 1998 house-dousing captivated Carl Blum, then deputy director of the county Public Works Department. Before he retired in 2000, Blum saw to it that one of the last parts of the city still prone to major flooding became a testing ground.
"Essentially, we are putting in a forest instead of a storm drain," Lipkis said. "The implications are huge for the future of L.A."
The project involves planting thousands of trees, turning old gravel pits into small lakes, and installing underground tanks to collect the rain that falls on hundreds of driveways, parking lots and rooftops.
Supporters say the Sun Valley experiment makes far more sense than diverting storm water into a drain that sluices it into the ocean -- the county's original plan for coping with the area's frequent flooding.
By directing the water into the ground, the project should also help recharge subterranean water supplies, reduce ocean pollution and return natural beauty to a community called neglected by neighborhood leaders.
The largely Latino working-class area is home to numerous trash dumps, auto dismantlers and recyclers, many of which sit alongside apartment houses and single-family homes.
The Sun Valley plan will cost in excess of $100 million, more than twice as much as the storm drain, and take at least a decade -- and possibly twice as long -- to complete.
Although the county, which is spearheading the project, has pledged $42 million and other state and local agencies are promising support, the project has not been fully financed.
Nonetheless, supporters say the benefits will greatly outweigh the costs.
"We started to say: 'If this works in one house, would it work on a whole block? An entire neighborhood?' " said Vik Bapna, the county official in charge of the Sun Valley project.
"We started to look at the technical aspects and determined that, yes, it was feasible. We looked at the financial aspects, the political aspects, and determined, yes, it was all feasible."
Sun Valley was built without storm drains, and it floods so frequently that television news crews routinely head there to film dramatic scenes of high water after rainstorms.