Residents on edge after slide in Riverton; engineers suspect secondary water caused land to shift

Posted at 7:06 PM, Sep 04, 2015
and last updated 2015-09-04 21:06:18-04

RIVERTON, Utah -- The land gave way dangerously close to several Riverton homes Thursday, and engineers said the moist ground is to blame for the slide; now the city and residents are left wondering where the water came from and if another slide will occur.

A massive 30-by-20-foot hole sits on a hillside, and the soil, still wet, has Riverton residents on edge.

"The whole mountain just kind of slid down," Robert Nielsen said. "It was real slow. It happened, I'd say in 5 to 10 seconds."

Nielsen watched the debris tumble toward his home Thursday evening.

"It was just slow motion, just coming down," Nielsen said.

Several homes were evacuated for a few hours, but Nielsen was displaced overnight.

"They said I definitely should leave," Nielsen said.

He was relieved when he got home Friday to see the hillside hadn't sent more debris tumbling toward his home.

"I plan on staying here as long as they'll let me," Nielsen said.

Engineers working on the hillside said excess water built up underneath the soil and made the ground collapse.

"A lot of moisture in the ground; there's a lot of water running through there, we're not sure where it's coming from," said Trace Robinson, who is a Riverton City engineer.

Engineers said the secondary water line, which has since been shut off, is likely the culprit.

"It's worrisome," Riverton Mayor Bill Applegarth said. "Anytime you have something that can damage someone's home and safety is a concern to us."

Throughout the next several weeks, engineers will have stakes in place that are linked to GPS coordinates to detect if the ground moves again. Until the land is stable, homeowners here say they will keep a close eye on the hillside.

"I think when the rest of it comes down, if it ever does, it might be dangerous," Nielsen said.