Rains Snarl Traffic; No Major Damage Is Reported

Driving rains snarled traffic, caused a minor mudslide and some flooding, but the Southeast area and Long Beach appeared to be in no immediate danger of major damage from the series of storms that drenched Southern California this week.

Local flood-control officials were confident Wednesday that the Southeast area and Long Beach would not suffer major flooding unless storm conditions worsened dramatically.

“It looks very comfortable,” said Greg Grigorian, chief of the U.S. Army Corps of Engineers’ local reservoir regulation section.

The Southeast and Long Beach areas have been spared much of the heavy rains that hit the San Fernando Valley and other parts of Los Angeles County earlier in the week.

During the 48-hour period ending Tuesday at 4 p.m., Long Beach had received less than one inch of rain, compared to the more than seven inches of rain that drenched Northridge during the same period, according to WeatherData Inc., which provides forecasts and weather data to The Times.

Wednesday’s storm packed more punch for the Southeast and Long Beach area. The area also could be hit by more storms this weekend, WeatherData meteorologist Mike Smith said.

Sheriff’s deputies on Wednesday afternoon evacuated the residents of 60 trailers at the Rio Puente Trailer Park on the 6600 block of Rosecrans Avenue in Paramount, Sgt. Mason Kenny said.

Rainwater rose to more than three feet in some places in the trailer park, located in a low-lying area that has flooded in the past.

The water entered some trailers, but no damage estimate was immediately available. There were were no injuries. An evacuation center was set up in a community building at Paramount Park, Kenny said.

Water and mud interrupted service on the Metro Blue Line Wednesday afternoon near the commuter train station on Willow Street and Long Beach Boulevard in Long Beach, said a spokesman for the Southern California Rapid Transit District.

Buses took passengers from that station to other stops.

The rain also closed portions of two streets Wednesday in Signal Hill, and other area cities reported lesser flooding. Rain and standing water also slowed traffic on the Santa Ana and San Gabriel River freeways.

Tuesday’s rains triggered a small mudslide at a construction site in the hills of North Whittier.

A river of mud flowed from a graded site at the northern tip of Bowen Drive down to Bronte Drive, said Whittier Police Lt. Don Desmaretz. Standard Oil Co. owns the site and plans to build homes there, Desmaretz said.

“It filled (the street) up with mud from curb to curb,” Desmaretz said.

The mudslide, which did not damage homes or cause any injuries, was cleaned up by Tuesday afternoon, Desmaretz said. Workers also rebuilt a retaining wall that had been overrun.

Flooding in the Southeast area and Long Beach is largely controlled by the Whittier Narrows Dam and several rivers that carry rainwater to the ocean.

During heavy storms, the Corps of Engineers uses the Whittier Narrows Dam to hold back water from the north and to control the flow of water down the San Gabriel, Rio Hondo and Los Angeles rivers to the ocean.

The Southeast area and Long Beach do not have the type of flood control basins that entrapped dozens of cars this week in the Sepulveda Dam Basin in Van Nuys when heavy rains caused the Los Angeles River to overflow its banks.

So far, the water level in the Whittier Narrows Dam has reached only 16% of capacity, a high mark that was set Tuesday, Grigorian said.

“There’s no stress on the dam,” he said.

At the height, the Corps of Engineers released water from the dam at a rate of about 22,000 cubic feet per second on Tuesday, less than half of what it can safely release, Grigorian said.

Similarly, Los Angeles County flood control engineers said the flow of water down the Rio Hondo, San Gabriel and Los Angeles rivers was well within the capacity of the channels to handle it.

A stream gauge on the Rio Hondo River at Beverly Boulevard in Pico Rivera recorded a high of 21,100 cubic feet of water per second flowing to the ocean on Tuesday. That was 52% of the channel’s capacity, said Ken Swanson, a supervising civil engineer for the county Flood Control District.

The waters running down the San Gabriel River have only accounted for 11% of capacity so far, Swanson said.

During the height of Monday’s storm, the water level reached 31% of capacity on the lower Los Angeles River at Wardlow Road in Long Beach. By then, the Rio Hondo had emptied into the huge concrete channel. The water level was no threat, but it certainly was a change from the trickle that has become commonplace during the recent drought years.

“This is the highest I’ve seen it,” said Dick Pasqua, a county flood-control construction superintendent, who works at the county’s flood-control station along the Los Angeles River in South Gate.

The recent rains have focused new attention on the ability of the Rio Hondo and the Los Angeles rivers to contain floodwaters during a catastrophic storm.

The Army Corps of Engineers first revealed in 1987 that the waters of a 100-year flood, which has a 1% chance of occurring in any given year, would overflow the banks of the Rio Hondo and Los Angeles rivers.

The flood would inundate parts of Bellflower, Bell Gardens, Compton, Downey, Lakewood, Long Beach, Lynwood, Paramount, Pico Rivera, South Gate and the South Bay city of Carson.

Damages would total $2.25 billion, according to the Corps of Engineers study.

Army engineers said Long Beach almost suffered a 100-year flood in 1980, when six closely bunched winter storms raised waters to the top of the Los Angeles River, splashing debris atop 20-foot-high levees at Wardlow Road.

To eliminate the chance of such flooding, the Corps of Engineers has proposed to spend $340 million to build concrete walls atop levees along the Rio Hondo and Los Angeles River and to raise bridges. Funding is not yet certain, but if all goes well, the project could be completed by about 2002, an official said.

“It sure crossed my mind when I was looking at the helicopters working in the (Sepulveda Dam) basin, plucking people off of cars,” said Downey City Manager Gerald M. Caton. “It gives more impetus that we need to get that river project done.”

Handling the Deluge

Flood Controls

A huge network of dams, basins and canals that channels most runoff water to the ocean protects the 4,000-square-mile Los Angeles County basin from major flooding during storms. The Sepulveda Dam Basin, which was flooded on Monday, is one of five such facilities operated by the U.S. Army Corps of Engineers in the county. In addition, the county Department of Public Works operates 15 dams.

Water running off from mountains and canyons is trapped by the dams, then channeled into the Los Angeles, Rio Hondo and San Gabriel rivers. The Los Angeles River collects water from the northwestern portion of the county. Water from the east flows into the Rio Hondo and San Gabriel rivers. Supplementing the dams are 2,370 miles of underground storm drains that collect runoff from streets, curbs and gutters.

Despite heavy rain this week, the system is not near capacity. The 15 county dams have a storage capacity of 116,000 acre-feet of water. As of Tuesday--the most recent day when figures were available--about 40,000 acre-feet of water were in the dams.

Officials say there also has been no danger of the Los Angeles River flooding during the storms. At their peak, more than 51,000 cubic feet of water per second rushed through the lower portion of the river to the ocean; the river could have taken as much as 146,000 cubic feet.

The county dams are monitored electronically and some have workers who live on the premises. The areas around some of the dams are used for recreational purposes during dry periods.

IN THE SOUTHEAST AND LONG BEACH AREAS, storm water is controlled by the Whittier Narrows Basin Dam, which is operated by the U.S. Army Corps of Engineers in cooperation with the county Department of Public Works.

The dam storage capacity is 18,950 acre-feet of water. In addition to the water that is released through the Rio Hondo and San Gabriel rivers to the ocean, some is captured and eventually used for drinking purposes.

That water is allowed to percolate into large spreading grounds in the Pico Rivera area. The recent storm has filled the grounds, which have a total capacity of more than 5,100 acre-feet.