NORTH SALT LAKE — Bob Odom is used to seeing a little bit more damage each year as a landslide carries his neighborhood a little bit further downhill. But this year the pace has slightly increased.

"It's little bit more than normal," Odom said, standing in a street that once was straight but is now bent and broken by a seemingly unstoppable force tearing his neighborhood apart.

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The landslide typically moves at a pace of a few inches a year. This winter, geologic measurements show that it sped up a bit. Though it's not a huge increase, it's enough to serve as a warning of other potentially troublesome landslide activity around the state.

Geologists believe the slight speed-up is due to an unusual amount of water that entered the soil during wet weather in November and December.

Odom's neighborhood is being destroyed by one of Utah's best-known and most-documented landslides. For years, residents of the Springhill neighborhood in North Salt Lake have watched the slide as it cracks walls, tears up sidewalks, breaks apart sewer pipes and makes homes unlivable.

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Elected officials and emergency responders say they learned several lessons in June 2010, when Little Cottonwood Creek overflowed and flooded areas of Salt Lake County.

"(It's) been so long you're just kind of numb to it now," Odom said. "You just wonder when you're going to have to go, and where you're going to go, and if we're ever going to get any resolution to helping us."

This year's wet winter probably won't help because moisture in the soil tends to increase landslide activity.

Utah geologists have documented 25,000 landslide-prone areas around the state. Every year a few of the slides reactivate, but experts expect more earth movement than usual this year.

"On really wet years, the landslides occur more frequently," said Gregg Beukelman, of the Utah Geological Survey. "And also, larger landslides and deeper landslides occur."

Sometimes landslides are deep and sudden, like the huge one that dammed up Spanish Fork Canyon in the 1980s. It created a lake that submerged the town of Thistle.

Sometimes only the top surface moves, washing mud and rocks into residential areas. Beukelman said it's possible there will be more of that kind of activity later in the spring, depending on the pace of the snowmelt. "We have them almost every year. So I would expect a number. What the number is, (I) don't know," he said.

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At a press conference called by county leaders to announce preparations for potential flooding, Fire Chief Michael Jensen of the Unified Fire Authority noted the unusual degree of saturation. "The soil moisture content, the percentage of soil moisture," Jensen said. "The ground just can't absorb any more. It's one of the highest we've seen in a long time."

State geologists have checked about three dozen other old slides in the last couple of weeks. So far, not too much out of the ordinary has been observed, except for the slight speed-up at Springhill. "Nothing that we're overly concerned with so far," Beukelman said. "It's going to require a lot of continued monitoring."

Because any extra water can increase the instability of an old landslide, Beukelman suggested a cautious approach to lawn watering this spring in slide-prone areas. "It's important that people minimize their irrigation if they know they're living on a landslide," Beukelman said.

Although Beukelman said there's reason for extra concern about landslides this year, he said a lot of it depends on the weather in coming weeks. If the snowmelt is gradual, he noted, there will be a lot less reason to worry.

Email: hollenhorst@ksl.com

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