Some Mapleton residents worry about future debris flows below burn scar

MAPLETON, Utah — Some Mapleton residents may need to evacuate every time it rains for the next three years — as their homes, below a burn scar, sit in the path of potential debris flows.

Those residents returned to their homes after evacuation orders were lifted Wednesday. But an 849 acre fire in September 2020 puts residents in the potential path of debris flows, particularly when heavy rain falls.

Blame it on the fire, not the rain

Mapleton Fire Chief Nicholas Glasgow said the flames from the Ether Hollow fire “burned right down to the backyards of some of these homes.” 

Now the left over burn scar means large amounts of dirt and debris could come down the hill when they have heavy rainfall.

“Hydrologists say the steep slopes and as little as 1/4 inch of rain in a 15 minute period could trigger as much as 9 feet of mud hitting some homes,” said Glasgow. 

Mapleton residents receive regular alerts

Last month, strong thunderstorms forced the evacuation of the Mapleton residents who live below the burn scar. 

“We had a very large amount of rain come down — we only had six to eight inches of mud come off of the mountain,”  Glasgow said.

Because of the limited amount of debris flows from July’s rain, Glasgow hopes this week’s storms won’t cause too many problems.

Glasgow said not only have they set numerous sand bag events to prepare, but the town also set up an early warning alert system. The system aims to alert people to the potential threat and evacuate them quickly, without loss of life.

Improvement expected in three years — or more

Unfortunately, residents of about 20 Mapleton homes can expect multiple evacuations over the the next three years, anytime a quarter inch of rain or more falls in a short period of time. Experts told Glasgow by the end of that time frame, the vegetation on the burn scar should grow back and mitigate the risk. 

However, he also said he hasn’t seen much re-growth on the hill due to the drought.  So he doesn’t know if that time period will be extended.

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