Study of L.A. River Freeway Plan Authorized by County Panel : Transportation: Use of the waterway is seen as a way to reduce congestion as much as 20% on two heavily used roadways, but environmentalists object.

Over the protests of environmentalists, the Los Angeles County Transportation Commission on Wednesday authorized a $100,000 study to determine the feasibility of turning 30 or 40 miles of the Los Angeles River into a part-time freeway.

The controversial proposal by Assemblyman Richard Katz (D-Sylmar) would create exclusive express lanes for buses, car pools and trucks along the winding floodway that extends from the San Fernando Valley through downtown Los Angeles to Long Beach. Most of the waterway was paved half a century ago to control flash flooding and carry waste water.

No one is certain if such a project would work or how much it would cost. But according to Katz, chairman of the Assembly Transportation Committee, the river traffic lanes would relieve as much as 20% of the congestion on the Ventura and Long Beach freeways. Critics say the scheme is not practical, would harm the environment and would be dangerous when storms send floodwaters raging down the concrete channels.

However, the commission’s preliminary study found “no fatal flaws” in the idea.

Consultants, after an initial look at the proposal, reported, “With modest improvements . . . the Los Angeles River and Tujunga Wash flood control channels could be used for transportation purposes between 220 and 300 days a year.”

As Katz envisions the route, the northern sections from the Valley south to Glendale and into downtown would be used by car pools, van pools and buses, weather permitting. The southern segments of the river expressway would be reserved for trucks running between the harbor and downtown. Trucks now primarily use the Long Beach Freeway.

Opponents, led by the environmental group Friends of the River, contend that such construction would destroy the fragile ecosystems that support green vegetation and wildlife along some segments of the river channel that are not paved. Hiking and equestrian trails near Griffith Park would be adversely effected, they contend.

Instead of diverting traffic into the river bottom and adding to urban congestion and air pollution, Lewis MacAdams, spokesman for the environmental group, called for a green belt, parks and more trails along the river, returning it to a more natural state.

The issues of safety and liability in the event of flash flooding were raised by Commissioner Ray Grabinski, a Long Beach city councilman who is concerned that motorists might get trapped in a flood.

“Who is responsible?” he asked Katz, who had spelled out the proposal for the commission a few minutes earlier.

Katz said the $100,000 study was needed to answer such questions, adding, “This may not be the answer to the transportation crisis in Los Angeles . . . but we have to look at what resources we have, see how we can get ourselves out of trouble.”

The commission authorized the study on a voice vote and directed that the questions of safety and liability be answered. The study will also determine how to handle the treated sewage that now flows down the river, an issue raised by opponents.

Consultants doing the study will also have to determine if the freeway lanes could be built without interfering with the flood control functions of the waterway. The freeway work would have to be coordinated with the Army Corps of Engineers, which has overall responsibility for the floodway.

A financial plan would also be developed during the study, spelling out how much the project would cost and how it would be financed.