Flash Floods

flashfloodUpperAntelopeCanyonThere are many beautiful canyons to hike in Arizona, but canyon hiking presents its own dangers. One of these is flash floods. Flash floods occur when a large amount of water drains into constricted channels. As the water travels downhill, it picks up momentum, more water, and large amounts of debris. More people lose their LIVES in floods than in any other weather-related event. Eighty percent of flood deaths occur in vehicles, and most happen when drivers make a single, fatal mistake – trying to navigate through flood waters.  Watch this to see how quickly a flash flood can occur:

Here are some things to keep in mind:

1. Watch for these warning signs:

  • Unusually hard rain over several hours
  • Steady substantial rain over several days
  • Rains in conjunction with a spring thaw
  • A monsoon or other tropical system affecting your area
  • Water rising rapidly in streams and rivers

2. In a terrain that is cut with canyons and drainages, flash floods can strike with little or no advance warning. Distant rain may be channeled into gullies and ravines, turning a dry wash or quiet stream into a rampaging torrent in minutes, even though the sun may be shining where you are.

3. DO NOT DRIVE OR WALK THROUGH FLOODED AREAS, even if it looks shallow enough to cross. The large majority of deaths due to flash flooding occur with people driving through flooded areas. Water only a foot deep can displace a 1500 lb. vehicle! Two feet of water can easily carry most automobiles. Roads concealed by water may not be intact, and the water may be much deeper than it appears.

4. If the vehicle stalls, leave it immediately and seek higher ground. Rapidly rising water may engulf the vehicle and its occupants and sweep them away. Remember it’s better to be wet than dead!

5. Don’t try to outrace a flash flood on foot. If you see or hear it coming, move to higher ground immediately. By the way, if you hear a train coming and you’re nowhere near a track, it’s probably a flash flood. Get rid of any encumbrances (trekking poles, backpacks, etc.) and quickly start climbing to higher ground, on the same side of the water as your vehicle if possible!

6. The National Weather Service will issue a Flash Flood Watch when heavy rains may result in flash flooding in a specific area. In this case you should be alert and prepare for the possibility of a flood emergency which will require immediate action. A Flash Flood Warning will be issued when flash flooding is occurring or is imminent in a specified area. If your locale is placed under a warning, you should move to safe ground immediately.

7. Campers/hikers should always determine if local officials, such as park rangers, post local cautions and warnings. This goes along with — in those areas where it’s required — completing any local tour/entrance/trip plan.

More/Optional Reading

If you find, like the hikers in this article did, that you absolutely MUST cross water, these tips will help to reduce the risk:

1.  Look for a safer crossing if water is fast and knee-deep or more; scout downstream of hazards like rapids, waterfalls, or fallen trees.

2.  Always ford a river at its widest point, where the water will be shallower and slower.

3.  Check your map for forks or braids, which split the river, reducing the volume of water.

4.  Wear sandals or water shoes to improve footing. It’s better to get your boots wet than take a risk going barefoot in tricky terrain.

5.  Unbuckle hipbelt and sternum strap before fording fast-moving rivers, so you can easily shed your pack if needed.

6.  Use trekking poles or sticks to improve balance and probe ahead.

7.  In strong current, cross at a slight angle, heading downstream but facing up. Lean a little into the current and step sideways.

8.  For a difficult crossing, ford as a group with arms locked. For three people, form a tripod (everyone facing in). Alternatively, tie a rope to a tree and send a strong hiker across to tie off the other end. The last member brings the rope.

9.  If you fall and the current takes you, flip on your back with your feet downstream. Ditch your pack if necessary and swim to shore as quickly as possible.

Just remember, crossing running water with elevated flows is a disaster waiting to happen, such as what happened recently in the Narrows at Zion.

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