Flash floods are a sudden increase in the depth and speed of water in rivers, streams, or washes due to heavy rain from thunderstorms. Flood waters carry large debris like tree trunks and boulders. Flash floods can occur at any time in Zion National Park and in the desert southwest.
- Flash floods are unpredictable.
- Flash floods can be deadly and death most often occurs from blunt force trauma.
- Slot canyons are particularly dangerous.
- You can’t outrun a flash flood.
- Flash floods can happen with sunny skies overhead.
For your safety, become familiar with the potential for flooding:
- Check the weather forecast and stop by the Visitor Center for up to date information.
- Watch for changing weather and a buildup of clouds.
- Heed warnings.
- Be aware of areas that are likely to flood and avoid those areas.
- Have a plan in case you encounter a flash flood.
- Leave an itinerary with someone and check in when you are done.
Become familiar with the flash flood potential rating system:
Not Expected: Flash flooding is not expected. Your safety is your responsibility.
Possible: Some slot canyons, dry washes, and small streams may
experience flash flooding.
Probable: Some slot canyons, dry washes, and small streams are
expected to experience flash flooding.
Expected: Many slot canyons, dry washes, and small streams are
expected to experience flash flooding.
Become familiar with signs of impending flash flood:
•Surge in water
•Change in water color
•Roaring water sound
•Increased debris in the water
During a flash flood:
•Stay out of the water-do not attempt to cross or enter the water
•Six inches of water can knock you off your feet
•Stay as high as you can and be patient. It can take hours for flood waters to recede
•Flash floods happen quickly so react quickly. Head for higher ground immediately. DO NOT take time to pick up your gear
For current information on flash flood risk, check the NOAA Flash Flood Rating forecast.
