And the truth is I had no idea. So, I did some research, and I'll share with you what I can. These aren't fool proof. Remember that flash floods can strike anywhere at anytime, so be careful and be prepared!
Check the Forecasts!
This advice only works in advance, unfortunately, but you really have to check the forecasts for regions where flash floods are a particular problem (certain trails, canyons, dry areas where the water won't absorb as quickly).
"Flash floods can happen anywhere rain falls faster (or in a larger quantity) than the ground can absorb, or anywhere a flow of water is temporarily blocked, then lets loose all at once.That said, they're most common in the Southwestern United States."
Know the dangers of the areas you're in, and check the forecast for them! If you're in an area away from home, as the locals which trails are ok for the day and which ones aren't so great. Check for rain not only in your area, but in surrounding areas, as runoff can end up affecting you, too. Be vigilant!
Not all weather can be predicted. Carry a NOAA weather radio for ready access to weather updates and warnings!
Stay away from danger zones!
Again, this only works pre-hike, but certain areas are more prone to flooding. Stay out of canyons, arroyos, and other landforms where escaping rushing water would be all but impossible. Wideness doesn't make it safe, either--check out the video above which shows flash flooding coming in to a large wash area.
Know the warnings signs of a coming flood!
There are certain things you can look for to know that a flood is coming:
- sudden change in clarity, volume or speed of running water you are near to
- rumbling sound of water and debris coming (check the video above!)
When you hear or see these, take action immediately! You won't have long to act.
Don't assume you're safe because the trail is open.
Sure, authorities will close the trails when flooding has already happened or is basically guaranteed, but you cannot rely on others to do your thinking for you by closing the trail. Use your sense, check the forecast often, and even if the trail is open, be aware that a flood could happen at any time.
Always Move Higher!
This particularly applies to when you're canyoning, but can be applied to any environment.
- However high you think you need to be to be safe from the flood, go at least twice as high.
- If getting caught, do not try to outrun the flood unless you are very close to the end. Instead, find a place where you can climb out of the canyon or to a secure place HIGH on the canyon wall.
- When camping in a narrow canyon, camp high above the canyon floor, above any signs of previous floods. Camp somewhere with safe pathways to go higher if needed.
In the video above, they might have wanted to just climb up a bit instead of trying to outrun the water. Still, one of them knew the way to a bigger area (see next point) so this worked for them.
Always Know You're Way Out
When in flood zones, it's really important to know where you're able to get out of the canyon, the fastest route to higher ground and more. Make sure you or someone you are with knows the area well, especially if there is a flood risk (but if there is a flood watch, you wouldn't be thinking of going out there anyways, would you?)
Pay attention to whether you are hiking up a narrow canyon drainage or down a narrow canyon drainage. This will help you know which way to watch for water.