THE SOUTHLAND DELUGE : Storm Throws Water on River Road Plan : Weather: The ‘limpid little stream’ turns into a roaring torrent. Critics jump on Assemblyman Richard Katz’s proposal to open concrete channel to traffic.

With the deluge of this week’s storms, the Los Angeles River is looking and acting like, of all things, a river.

The normally pallid concrete channel, described by city water engineer William Mulholland at the turn of the century as a “limpid little stream,” is raging, churning, roaring and tumbling. Usually the butt of jokes, the city’s namesake waterway is suddenly commanding respect--and generating some political controversy as well.

Standing Tuesday near the banks of the invigorated river, Los Angeles City Councilman Michael Woo poured cold water on a proposal by Assemblyman Richard Katz (D-Sylmar) to turn the customarily parched riverbed into a roadway to ease freeway traffic.

“One thing is certain: This is no place for trucks and cars,” said Woo, the swollen river pounding behind him.

Several hours later, Mayor Tom Bradley also ridiculed the roadway proposal. “This is the wrong place to have a freeway,” Bradley told a City Hall news conference. “It couldn’t have been better emphasized.”

Katz, who along with Woo is considered a likely candidate for Bradley’s job in 1993, has long championed the idea of converting the underutilized riverbed into a traffic-weary commuter’s dream. As such, he has grown accustomed to derisive comments and mocking sneers, but Tuesday he testily denounced the latest wave of criticism.

“Freeways were flooded yesterday, and we are not talking about abandoning using freeways,” Katz said in a telephone interview from Sacramento. “You have to shut down (I-5 at) the Grapevine when it snows, but you don’t restrict people from using it the rest of the year.

“We’ve got people being lifted off trees in the Valley and these guys got nothing better to do than make cheap shots.”

Although the specifics of his plan have changed over the years, Katz has suggested using the river channel during dry weather for buses and car-poolers between downtown Los Angeles and the San Fernando Valley and for trucks between downtown and the ports of Los Angeles and Long Beach.

The suggestion has never been popular with environmentalists, who would much rather see the 50-mile waterway used as a park and nature reserve during the 220 to 330 days of dry weather each year. The Army Corps of Engineers, which began paving the riverbed after a series of violent storms in 1938, has also been critical of the idea, insisting that the roadway would interfere with the river’s primary purpose as a flood-control channel.

But bickering about the “Katz Freeway”--as some critics have dubbed the proposal--took on new significance with the onslaught of this week’s storms. At least two government agencies have been studying variations of the Katz idea, but until now discussions of complications from severe wet weather have been limited to the chalkboard.

Suddenly, the Los Angeles River transformed itself into a real-life laboratory, and critics have jumped on the occasion to deride the roadway proposal as ludicrous.

“Today the foolishness of the plan just strikes me as being so obvious,” said Woo, insisting that his news conference was not a cheap shot. “In the midst of the rain, it is so obviously without common sense.”

Col. Charles S. Thomas, the Los Angeles commander of the Army Corps of Engineers, warned the City Council on Tuesday that there would have been “great potential for loss of life” had the riverbed been occupied by motorists on Monday. Dozens of vehicles were nearly submerged when the river overflowed in the Sepulveda Dam Basin in Van Nuys, flooding nearby Burbank Boulevard.

Consultant Gregory LeFrois, who headed a recent study on the roadway idea for the Los Angeles County Transportation Commission, said it was unfair to assume that a riverbed roadway would have been open to traffic during a winter storm. Although his report did not address the issue, LeFrois said Tuesday that procedures for closing the roadway were discussed by authors of the report.

“There would probably be some pretty strong gates in place that would come down into the entrances,” said LeFrois, an engineer with Howard, Needles, Tamen & Bergendoff. “There would be a joint effort between the U.S. Army Corps, the National Weather Service and Los Angeles County Flood Control to determine when to close the roadway.”

Even so, in the study being reviewed by county transportation officials, LeFrois’ firm recommended construction of elevated car-pool lanes north of downtown Los Angeles along the river’s banks, which would eliminate concerns about flash floods and sudden weather changes.

Katz said he would support such a change, even though it would deviate substantially from his original idea.

“The notion that you ought not to examine anything simply because you haven’t done it before is pretty pigheaded,” Katz said. “I think my idea of trying to solve the problem is good.”

Times staff writer John Schwada contributed to this story.