Rains Cause Section of Wall to Fall Into Empty Reservoir : Landslide: Metropolitan Water District officials, who are seeking to stabilize the immediate area, say no Newport homes are at risk.

Heavy weekend rains provided the last straw for the empty San Joaquin Reservoir here, causing a 150-foot section of the east wall to break into several pieces and drop about 50 feet.

No one was injured in the slide Sunday, and none of the houses surrounding the reservoir are in danger, according to officials with the Metropolitan Water District, which owns the problem-plagued reservoir that has been drained and out of service since December, 1993.

Edward Means, MWD’s chief of operations, said Monday that officials have anticipated for more than a year that a landslide of this magnitude would occur because the area was found to be prone to slippage.

“There’s no emergency kind of situation here,” Means said. “It’s dramatic in the sense that it’s very visual. This was all but inevitable.”

Water officials began noticing hairline cracks in the 29-year-old wall in February, 1994, after the water had been drained from the reservoir, Means said. Geotechnical experts determined that the land beneath the east wall was slowly sliding toward the reservoir’s floor.

Sections of the wall dropped about two feet after the record-setting storms in January, he said.

“This thing failed a long time ago,” Means said. “Now, it’s just the consequence of that failure.”

The 14 homes surrounding the reservoir are in “no imminent danger,” as long as the landslide is contained where it is, said Larry Thomas, spokesman for the Irvine Co., which designed the housing developments around the reservoir.

“We do believe that there is some urgency to shore up the slide area,” Thomas said.

Means said the facility has had a history of setbacks since opening in 1966, ranging from minor landslides to water quality problems. But this is the largest landslide the MWD has had at any of its reservoirs, he said.

The reservoir is shared by eight water and governmental entities including the MWD, the Irvine Ranch Water District, Mesa Consolidated Water District, and the city of Huntington Beach.

About 200,000 south and coastal Orange County residents will be served by the 1-billion-gallon facility once it is fixed and reopened, Means said.

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MWD officials traveled to the site early Monday to try to figure ways to stop the slippage. Means said workers will probably have to divert a small v-shaped ditch, which is currently emptying into and saturating the landslide area.

Workers also will drill “hydroaugers,” which are basically horizontal wells, into the crumbled sections of the east wall to soak moisture out of the hill, he said.

MWD officials hope to have the repairs completed before the end of the week because more rain is expected Wednesday; forecasters say it will continue for the rest of the week. If the repairs have not been finished when the storms arrive, the crews will “work through” the rain, Means said.

“I wouldn’t be surprised with the other rains if (the remains of the wall) just kept moving down,” Means said.

Eventually, the MWD will fill part of the reservoir with dirt, cutting off the landslide area and reducing water capacity by about 3%, he said. Those permanent repairs, expected to cost $6 million, must be completed before MWD can reopen the reservoir.

Although Sunday’s landslide should not cause those costs to increase, it will probably put off the repairs for at least a year, Means said. He added that rate-payers will be only nominally affected by the repair costs.

“Any time you have a failure like this at a public facility, ultimately it turns up somewhere on the water bill,” he said.

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Wall Tumbles Down A 150- foot section of the San Joaquin Reservoir wall collapsed Sunday night. The asphalt wall crumbled, displacing about 200,000 cubic yards of asphalt and dirt.