More sinkholes in California

Volcano? California homes sinking one by one in now abandon subdivision near volcanic field

Inquistr,

12 May, 2013

Homes are sinking  in a California subdivision built on top of volcanic country. Eight homes have been abandoned so far and 10 more are under an imminent evacuation notice after cracks appeared in the ground and entire sections dropped 10 feet into the ground.

A Tudor-style house was a long-time dream of Scott and Robin Spivey, who lived in the Lake County neighborhood for 11 years.

But the Spiveys were forced to evacuate when cracks began appearing in their walls in March. The small cracks turned into gaping fractures, which culminated in their 600-square-foot garage dropping 10 feet below the street.

It didn’t take much longer for the houses on both sides of the Spiveys’ dream house to collapse as well. Scott Spivey, a former building inspector, stated, “We want to know what is going on here.”

Randall Fitzgerald, a writer who bought his home in Lakeside Heights a year ago, added, “It’s a slow-motion disaster.” Frustrated homeowners have been forced to watch as a hilltop with sweeping views of Clear Lake and the Mount Konocti volcano slowly swallows the subdivision.

The California homes that are sinking were built 30 years ago. The movement is different than the sinkholes in Florida, which have been known to swallow entire homes in an instant. Rather, this collapse can move several feet in one day, then just centimeters the next.

County public works director Scott De Leon added that the sinking homes are confusing to more than just the homeowners. He added, “We have a dormant volcano, and I’m certain a lot of things that happen here are a result of that, but we don’t know about this.”

Some of the subdivision movement is happening on shallow fill, according to De Leon. However, a geologist has warned that the ground could be compromised down to bedrock, which rests 25 feet below the surface. Cracks have also appeared recently in roads well beyond the shallow fill.

In a bid for answers to stop the California homes from sinking further, officials have inspected the development’s original plans. But they have found nothing to account for the problem. Tom Ruppenthal, a consultant from Utility Services Associates in Seattle, suggested that groundwater may have shifted course.

The homes that have already sunk have been tagged for mandatory removal. But the hillside is so unstable, it can’t support the equipment needed to complete the job.