Wet Canyon Floods on Mount Graham: What you need to know to about flash floods

By Brooke Curley

brooke@gilavalleycentral.net

SAFFORD – A seemingly innocent afternoon thunderstorm can turn deadly for anyone down stream. Before camping, or even going for a walk in the rural areas, know these flash flood facts before you go.

In light of the recent heartbreaking loss of life in the Tonto National Forest due to flash flooding, Gila Valley Central contacted Coronado National Forest Public Affairs Specialist Heidi Schewel to gain a firm understanding of mother nature’s brutal work when it comes to flash floods.

Schewel stressed the importance of checking the weather forecast before setting out for outdoor adventures. If it will rain anywhere near a proposed campsite or hiking trail, and especially if there will be thunderstorms up stream, it is advisable to not camp or trek near that particular spot.

“We tell people, know before you go,” Schewel said. “Check the forecast for the area you’re going to be going into. Be aware that low lying areas and drainages such as washes, canyons, and so forth should be avoided during the monsoon season.”

Contributed Photo: Wet Canyon on Mount Graham turned into a river filled with flowing debris after rains poured on the mountain Saturday.

The main aspect of flash flooding is the basic fact that water will choose the path of least resistance when it comes to monsoon rain bursts. Canyons and washes are specifically created by extra water flow and will fill in times of excessive rain to help drain the area. Wet Canyon on Mount Graham turned into a raging torrent Saturday after rain hit the mountain upstream.

Schewel told Gila Valley Central that one fact of importance is that flash floods are a traveling occurrence and is caused by rain. However, it doesn’t have to be raining at the site of a flash flood. To avoid any possible oncoming flash floods, hikers and campers must always be aware of what’s happening upstream and to stay out of canyons, creeks, and washes in monsoon season.

“One thing that’s really important for people to know is that it doesn’t have to be raining where you are for a flash flooding to occur,” Schewel said. “If it’s raining upstream than that water is going to drain due to gravity and it’s going to follow through those water courses that’s just the way things work naturally, so people need to avoid those areas and not put themselves at risk. So, it’s really important to watch what’s happening and know what’s happening upstream above you because if water falls on the ground it’s going to drain somewhere and those canyons, that is their functions, to drain the water away.”

According to the National Weather Service, flash floods usually form within six hours of the immediate cause. However, narrow and steep valleys tend to create a rapidly flowing water flow that can rise to a considerable depth, and turn a mountain stream into a 10-foot deep river in less than an hour. Rocky terrain and clay soil do not let the water soak in, causing the rainwater run off to become more intense.

Contributed Photo: The area around Wet Canyon on Mount Graham was closed Saturday due to flooding waters.

“Be aware of what is going on around you, if stormy conditions develop you are going to want to head for higher ground or protection indoors,” Schewel said. “If it’s an electrical storm with thunder and lightning, of course, you would want to seek shelter but not under a tree. This is really important. People really need to think seriously about responsibility for their safety and take every precaution that they can to prevent themselves from being in a hazardous situation if at all possible.”

Flash floods are the leading cause of whether-related deaths in the United States. In 2016, 126 people died in flooding accidents. Of the 2016 deaths, 58 individuals died while in their cars, possibly trying to cross a flooded road or bridge. When a motorist is confronted with a flooded road or bridge, it is best to go back instead of trying to cross it. A mere two feet of water can carry away a vehicle.

Flash Flood Precautions

Know before you go

If waters rise around your vehicle but aren’t moving, abandon the vehicle. However, do not abandon the vehicle if the water is rushing by.

If a storm is upstream, avoid low areas such as canyons, washes, and creeks. It doesn’t have to be raining for a flash flood to occur in your area.

Flash Floods can happen at any time, day or night.

Avoid camping in canyons, near creeks, or in washes during monsoon season.

The chances of flash floods are increased after and during a drought because the ground is incapable of absorbing a sudden downpour of rain, causing dangerous runoff.


Flash Flood Facts

Flash floods can create walls of water from 10 to 20 feet tall.
A car can be swept away in as little as two feet of water.
If uncovered skin comes into contact with flood water, be sure to wash it because the contents of the water are unknown.
Six inches of flash flood water can knock an individual down.
Flash floods occur in every state in the United States.
Floods are the most widespread natural disaster aside from wildfires.
sources:

http://www.floodsafety.noaa.gov/hazards.shtml

http://www.nws.noaa.gov/om/hazstats/flood16.pdf

dosomething.org,

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