"The storm that hit Cache Valley last week, if that were to hit Utah County, you would see much the same kind of problems," Julander said. When storms are projected to pound, "it makes us a little nervous, because you could be melting two inches of snow a day, and then putting two, maybe three inches of rain on top of that."

The Provo Canyon area has also received higher than average precipitation, but Julander said that area is not really a concern because Jordanelle and Deer Creek reservoirs have the capacity to hold most of the runoff. But heavy precipitation on saturated ground could produce flood conditions just about anywhere.

McInerney pointed out that storms that produce two or three inches of water, like the one that hit Cache Valley, are not all that common.

"If we look at the amount of rain that falls in a couple of hours, it's typically in the range of 0.2-inch, 0.3-inch, maybe 0.5-inch in a thunderstorm per hour," he said. "But to put together something of 2 or 3 inches, it's highly improbable, but it's possible."

It is also possible that if floodwaters develop in canyons, they could come down in the form of debris flows, which occur when water-saturated ground breaks off and flows down slopes, gathering trees, rocks and other debris as it goes.

Utah Geological Survey geologist Richard Giraud said sandbagging is not very effective in diverting debris flows, as they have a consistency much like wet concrete. Giraud said a cubic foot of water typically weighs 62 pounds, while a debris flow mix weighs somewhere near 140 pounds per cubic foot.

The best way to mitigate the effects of debris flow is to clear riverbeds and other channels of debris and build debris basins to slow the mixture's flow. Utah County built several such basins following the 1983 floods, including one at the mouth of American Fork Canyon. While basins will not stop a debris flow, they can slow it down and eliminate larger pieces of debris from doing damage downstream.

Landslides are also a potential danger in Utah County. The county has received from 120 to 130 percent of its usual precipitation since October, and saturated soil is a main cause of landslides.

Giraud said landslides are harder to predict because they are influenced more by long-term precipitation. But he said most landslides occur in areas that have slid previously, either in recent memory or in their geologic past.

"It's very important to recognize that old landslides are very prone to reactivate," he said.

Giraud suggested that residents who think they may live near a historic landslide area (see map) watch for signs of soil movement such as ground and house-foundation cracks.

Utah County Engineer Clyde Naylor said the county has been taking measures to prepare for possible flooding, including clearing debris out of riverbeds around the county for the past six weeks. "We have a lot of sandbags in Utah County, and sand at various locations. That's about the only thing that we can do in advance, other than making sure the streams are clear."

Julander said he and other hydrologists will be watching to see if the current cool weather pattern holds because that will mean an ever shorter window for snowpack to melt.

Whether flooding occurs or not, McInerney cautioned residents to be especially careful near streams and rivers this year.

"These mountain streams are incredibly dangerous," he said.

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E-mail: mdecker@desnews.com