Slide Perils Homes, Spurs Evacuation of 4 Families : Natural disaster: ‘You could hear it crack,’ one San Juan Capistrano resident said of the hillside above Dana Mesa Drive.

Five homes were threatened Saturday after a slow-moving landslide between two hillside streets dumped earth, trees and shrubs across the back-yard retaining walls of two residences.

No one was injured, and no houses were damaged. But city officials warned that it might be several days before they can determine when it will be safe for at least four families, who were evacuated, to return to their homes on Purple Sage Lane and Dana Mesa Drive.

A geologist summoned to the site by city officials speculated that the slide might have been caused by the recent heavy rain in combination with long-term over-watering of yards by homeowners.

“Sometimes if people over-irrigate their lawns, the ground just can’t take that constant saturation,” said David Peter of Peter & Associates of San Clemente, a geo-technological firm. “The recent rains may have been the last straw the earth could take.”

Purple Sage Lane is about 40 feet higher than Dana Mesa Drive, with a slope between them of about 33 degrees, according to Ron Sievers, director of public lands and facilities for the city.

“This development has existed for 22 to 25 years, and there’s never been a problem,” Sievers said. “It’s a very unusual movement. We really can’t say with any certainty right now what went wrong.”

Residents in the 25600 block of the two streets began to notice the earth moving between their back yards at about 9 a.m. City officials estimate that the slow-moving slide lasted about 30 minutes as it deposited debris in a number of yards.

“You could hear it crack and a lot of dirt was just rolling down the hill,” said Clarissa Alvarez, who lives on Dana Mesa Drive.

The slide crumpled her back-yard retaining wall. Her neighbor, Jeff Morgan, had an even closer call. A 30- to 40-foot-tall pine tree unearthed by the slide toppled toward his house but crashed just a few feet short of it.

“That tree could have caused some serious damage if it had been any closer,” Sievers said.

One woman was told she could remain at home, but authorities recommended that she live in the front part of her home on Dana Mesa Drive. The American Red Cross provided a hotel room for the night for Alvarez and her two children.

The Morgans and the Jack E. Swallows family on Purple Sage Lane reportedly spent the night with friends. One of their nearby neighbors, whose property was not damaged, moved out and spent the night with relatives, Sievers said.

The heart of the damage was a huge fault that ran about 15 feet deep and slid down the hill about 4 feet. Officials feared that it might move even farther if it filled with water.

City officials and work crews spent much of the afternoon sandbagging a drainage ditch along the middle of the hillside as a safeguard against further erosion if more rain comes as predicted. Sandbags also were placed around homes on Purple Sage Lane.

Peter, whose brothers Bruce and Steve worked alongside him, said the biggest concern was the Swallows residence, where cracks in the earth extended almost to the back-yard patio.

The slide occurred at a time when most of the city’s resources were tied up with the annual Swallows Day Parade. Sievers said he had to call on workers from Botoco Inc., which does maintenance contract work for the city, to help sandbag the area.

“There’s a lot of anxiety among the neighbors,” Peter said. “They have a right to be worried. This could become very costly for them.”