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A Concrete Plan for Nature's Way : Pacoima Wash: A $6-million project to begin next month will transform the last unimproved section of the stream bed to an efficient, if lifeless, flood control channel.


One of the last natural stream beds on the floor of the San Fernando Valley is an ugly sight.

The nearly two-mile stretch of the Pacoima Wash between the intersection of Woodman Avenue and Lassen Street south to Parthenia Street is a weedy, dusty eyesore littered with shopping carts and household trash. Apartment buildings back up to it. Graffiti mar fences along it. And in at least one place, a junkyard juts 20 feet into it.

Historically, its headwaters are in narrow, steep Pacoima Canyon. But the last time water from there flowed through the wash was probably in the 1950s, before a diversion channel was built by the U. S. Army Corps of Engineers.

Still, some will mourn when the Los Angeles County Department of Public Works begins construction next month on a $6-million project to replace the stream bed through Sepulveda with a concrete flood control channel or underground drainage pipes.

At a time when environmentalists are lobbying for the removal of the concrete linings from the Los Angeles River and the lower Arroyo Seco in Pasadena, some find it distressing that an additional channel--efficient for carrying water but nonetheless antiseptic and fenced in--is to be built.

"There are two ways to deal with flood control," said Michael S. Anderson, a civil engineer who is head of drainage planning for the public works department. "The No. 1 way is you keep the people away from the water . . . and the other way is to keep the water away from the people."

In the case of the Pacoima Wash, he said, houses and businesses have been built right to the stream bed's edge, leaving no room to allow it to overflow. The only remaining option is to dig a channel so that the water flows quickly away, he said.

"There is nothing wrong with flood protection. We need flood protection," said Denis Schure, a Sierra Club activist. "But they could take fresh looks at it that give us other uses for that investment, in addition to flood protection."

As an example, Schure, a canoeing instructor, points to a stretch of the Los Angeles River near the Sepulveda Basin that he would like to see turned into a public white-water course. He is among a growing group of Southern Californians who believe that the region's rivers have been treated merely as a plumbing system instead of as part of a rich natural and recreational resource.

For example, public and private studies have concluded that development, flood control, gravel mining, water projects and agriculture have wiped out as much as 95% of the riparian habitat that once existed in the state. As a result, as many as 17 of the 111 bird species that breed or forage in those areas are no longer evident.

With that record of neglect, Schure and others now say what is left must be preserved. "The people in the area have been so oblivious to the stream-side environment for so long, they've forgotten that there's anything like that in the city at all," Schure said.

Don Nichols, the public works department's conservation and hydrology chief, patiently listens to such comments and then offers this observation:

"During prolonged periods of drought, it's natural for all the folks around town to suspect the merit of having built all these heavy concrete structures. It takes a gully-washer every few years to wake us up and make us say, 'Gee! I didn't know that river could do that!' "

County engineers calculate that portions of the seemingly dry wash could gush with as much as 18,500 gallons of water per second in the event of a 50-year flood--one so severe that, in any one year, there is only a 2% chance of it occurring.

In its present condition, the stream is capable of carrying only 10% of that amount. The rest would flood the surrounding area, flowing through streets, inundating homes and carrying away cars. Lives, almost certainly, would be in danger.

At present, even moderate rainstorms cause Plummer, Nordhoff, Rayen and Parthenia streets to flood. Those streets have often been underwater during past storms--so much so that rickety bridges were built in the 1950s to allow pedestrians to cross. And intense development in the area has increased the flood threat by spreading concrete and asphalt over open land.

Richard Urban, who has lived in the 9000 block of Kester Avenue next to the wash since 1957, said he won't miss the stretch of natural terrain when it's gone.

"It's always been a dry wash until we have a torrential rainstorm. When they get done concreting it up, we won't have water on Rayen Street every time it rains three inches," Urban said.

To build the channel, the county has to buy additional property in places, and Urban and some of his neighbors are unhappy with the amount of money the county wants to pay for their land. But few, if any, want to see the remnant of the wash remain as it is.

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