Mud flows but not to homes

PROVO — An intense thunderstorm in the wee hours of the morning triggered a small mud flow on Provo's east bench on Wednesday.

But residents were unaware of the dangers lurking in the mountains above. Thanks to a diversion channel, completed in early August, the soupy mud flow never reached their homes.

"Most people didn't even know there was any sort of problem," said Ted Gwilliam, who lives in the Buckley Draw neighborhood.

Provo officials suspect the mud flow came down at approximately 3 a.m. The slide surprised officials, since the alarm at the remote automated weather station, which measures the amount of rainfall in Buckley Draw Canyon did not go off.

Tricia Porter, Provo's emergency management coordinator, said she had no idea there was a mud flow until she got to work later that morning. The new trench calmed all her fears about a possible mud flow.

"That (the trench) is the biggest thing we could have done to help protect that neighborhood," Porter said. "It's in place, and it works. That gives us a sense of confidence that we did not have before it was in place."

Provo officials have been worried about a possible mud flow in the Buckley Draw area ever since last summer's 3,000-acre wild fire. The high-intensity blaze left too much bare soil exposed without any vegetation, which is the perfect recipe for a mud flow, said Rich Giraud, a geologist with the Utah Geological Survey.

Wednesday's mud flow followed a similar pattern to last year's slide in Santaquin, when more than 2 dozen homes were ravaged by mud, Giraud said.

"We get gentle rainfall over a period of hours, and that's followed with some brief intense thunderstorm rainfall," Giraud said. "What's important to note is that this gentle rainfall that precedes the thunderstorm rainfall, basically it's saturating the soils. When you get that intense thunderstorm's rainfall, the soils can't saturate the water and the mud runs off."

The rain started coming down at about 6:30 p.m., Porter said. According to the National Weather Service, the area only received about a quarter of an inch of rain. But what started as a small rainstorm quickly turned into 30 minutes of hard hail.

"It did wake me up," Gwilliam said. "I don't think the city realizes that is why we had a debris flow. I suspect it is because of the hail."

Officials from Provo, the Utah Geological Survey, the National Weather Service and the forest service will work together for the next few days to determine the cause of the mud flow.

Beckstrom said the trench diverted a possible disaster in the Buckley Draw neighborhood. Several homes could have been flooded with the soupy mud that the trench stopped in its tracks.

"It's kind of like when you have the sewer back up in your basement — it doesn't take a lot to cause a big problem," Beckstrom said. "But had it (the trench) not been there, it would have been a mess in the streets."

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