By Ruth Longoria

A leak in a sprinkler system is being blamed for a large portion of a resident’s backyard breaking away and swooshing down a hillside, across Forest Avenue and into the yards and driveways of neighboring homes Sunday morning.

“I heard a loud noise and then the trees started disappearing,” Jim Stapper said of the slide that took away most of his backyard.

Stapper, a 15-year Forest Ave. resident, said he heard water running before 9 a.m. Sunday. No faucets were turned on inside his house, so he checked the water faucets outside. A few minutes later he heard the hillside give way. No one was injured in the slide and there was no structural damage to any of the 12 residences involved. “We were fortunate, it could have been a weekday when kids were down below getting ready to go to school,” Stapper said.

Aaron Ascher, of Ascher Construction, also feels fortunate. He was working on a landscaping project Friday afternoon directly below Stapper’s home, across the street where Forest Avenue curves around the hill. Ascher said he’d have been working there again Monday morning if the slide hadn’t occurred. “God was watching out for me,” Ascher said.

The project he’d been working on — a 5,000-square-foot rose garden, with rhododendrons, trees, shrubs and pathways and several other trees and shrubs — is no more. Mud and debris eclipsed Ascher’s three weeks of work, and wedged rockery, tree limbs and a large rose bush from Stapper’s yard in it’s place. A boat trailer was pushed through the mud and is now bent around one of the large trees that remain. A fruit tree formerly from Stapper’s yard now blocks the driveway to that home.

Mercer Island Fire and Police arrived within minutes of the landslide. They shut down service water lines and drained a nearby pool thought to be a potential hazard, according to information provided by the fire department. City Maintenance, Development Services and a geotechnical engineer were called in to assess the situation and provide technical assistance. Maintenance crews cleared the road and most of the driveways affected, said Glenn Boettcher, city maintenance director. The slide occurred mostly on private property, so the city only has a responsibility to clear streets and help provide driveways access. But city workers were able to point resident in the right direction in cleaning up the rest of the mess and stabilizing the hillside, Boettcher said.

Stapper hired a crew from Earthwork Enterprises Monday to stabilize the hillside and place weighted down tarps over the side of the hill to prevent the soil from additional sliding.

Boettcher said landslides aren’t uncommon on the Island. “Most of the perimeter of the Island has a problem with slope stability, it’s a fact of life,” Boettcher said. “There’s a significant area of unstable soils, so we do everything we can to stabilize slopes, and if something like this happens on private property we provide technical guidance to the homeowner. It’s a big thing for homeowners to deal with.”