Debate Over L.A. River Escalates

It was a quintessential Los Angeles moment. While ducks gamboled beneath graffiti in a concrete channel of the Los Angeles River and a Metrolink train passed overhead, two news conferences, designed to make the opposite points, took place Wednesday within 50 feet of each other.

The Army Corps of Engineers, smarting from accusations that it dragged its feet in allowing such channels to be cleared of vegetation for predicted El Nino storms, invited reporters to climb down the river’s concrete banks and watch workers remove brush.

A few yards away, state Sen. Tom Hayden (D-Los Angeles), flanked by representatives of Friends of the Los Angeles River and the Sierra Club, took the microphone to deplore the brush clearance.

He scoffed at the idea that clearing vegetation from clogged flood control channels would increase their capacity to carry water in event of heavy storms, and said Los Angeles County officials who had pushed for permission to do so were simply using the threat of El Nino to destroy valuable wetlands.

“The possibility of an El Nino event should not be used to destroy vegetation and habitat in the Los Angeles River,” Hayden said. That the corps had sped up the permit process to allow Los Angeles and seven other counties to clear out their concrete lined, soft-bottomed channels--all of which were engineered for flood control--presents “a mortal threat to every river in the United States,” Hayden said.

The Hayden news conference attracted so much attention that the corps canceled plans for a presentation by officials, opting instead to fell a willow tree for the cameras.

“Don’t you know that there are bugs in those trees that the birds eat?” Marcia Hanscom, co-chair of the L.A. River Task Force, complained to a corps official after the tree came down.

It was a clash not only of values, but of strategy.

To Hayden and the environmentalists, the way to prepare for storms is to develop a new, more natural system for flood control. Taking vegetation out of streams won’t increase their capacity, they argue, but will only destroy valuable habitat for birds and other creatures.

Flood control experts, on the other hand, say the vegetation clogs the channels, reducing the capacity for which they were designed.

“When you have an area that’s taken up by vegetation, common sense tells you that area can’t be taken up by water,” said Jim Noyes, chief deputy director of public works. “If the water can’t go there it will rise in height” and overflow the banks.

At the heart of the disagreement between the environmentalists and the flood control experts is Los Angeles’ system of concrete-lined channels, which were engineered roughly along the paths of streams and rivers in a series of projects from the 1930s through the 1970s.

At the time they were built, it was believed that by containing water in concrete channels, cities could avoid flooding and therefore build houses and other buildings right up to the banks.

But that only works, engineers say, if the channels are kept clear. So under contract agreements with the corps and others, local governments including the county agreed to keep them free of brush, trees and debris.

However, increased environmental regulation and money troubles at the county level slowed down the rate at which the channels were cleared. Over the last few years, reeds, willows and other plants have grown up in the channels that have soft, or natural, bottoms--left unpaved so some of the runoff can percolate down into the soil below.

Last month, Noyes told the Board of Supervisors that the county had applied for permission to clear the brush nearly two years ago, but regulators had held up the process, allowing even more plants to grow.

With dozens of channels down to less than two-thirds of their original capacity, he said, severe flooding could result if the growth was not cleared.

Under pressure from the supervisors and others, the corps sped up the process, and last week granted an emergency permit to allow the county to clear the channels.

But environmentalists want to preserve these plants, saying they are habitat for birds and other creatures. Regulatory delays, these activists suggest, far from being problematic, are proof that the system is working to protect valuable resources. They criticize the new emergency permit, saying that it does not allow the public to comment on proposed work in the riverbed.

Instead of clearing the channels and continuing to rely on concrete, said Lewis MacAdams, spokesman for Friends of the Los Angeles River, the county should pull up asphalt parking lots and allow more rain to soak into the earth.

Such actions might help, said Fred-Otto Egeler, spokesman for the Army Corps of Engineers, but neither the corps nor the county has jurisdiction over those things.

“It will help water percolate into the aquifer,” Egeler said. “That’s only logical. But then what are they going to do with all those thousands of cars?”