Sept. 17 -- The National Weather Service has announced that heavy rain will be possible late this afternoon and tonight across portions of the Cascades, which may result in flash flooding and debris flows around areas recently burned by the Riverside fire in Clackamas County, including the Highway 224 corridor between Estacada and Ripplebrook. Officials are recommending you avoid the area tonight if possible.
Debris and mud flows are rivers of rock, earth and other debris saturated with water. They can flow rapidly, striking with little or no warning at avalanche speeds -- faster than you can run. They also can travel many miles from their source, growing in size as they pick up trees, boulders, cars and other materials. Debris flows don’t always stay in stream channels. And they can flow sideways, as well as downhill.
Listen and watch for rushing water, mud, unusual sounds
- Unusual sounds, such as trees cracking or boulders knocking together, might indicate moving debris.
- A faint rumbling sound that increases in volume is noticeable as the landslide nears.
- Fences, retaining walls, utility poles, k-rails, boulders or trees move.
During a landslide or debris flow
- Heed all warnings and evacuation notices.
- Never cross a road with water or mud flowing.
- Never cross a bridge if you see a flow approaching.
- It can grow faster and larger too quickly for you to escape.
- If you do get stuck in the path of a landslide move uphill as quickly as possible.
- Avoid river valleys and low-lying areas during times of danger.
- If you are near a stream or channel, be alert for any sudden increase or decrease in water flow or water that changes from clear to muddy. These can be signs that a landslide or debris flow is coming.
After a landslide or debris flow
- Stay away from the slide area. There may be danger of additional slides.
- Listen to local radio or television stations for the latest emergency information.
- Watch for flooding. Floods sometimes follow landslides and debris flows because they may both be started by the same conditions.
- Check for injured and trapped persons near the slide, without entering the direct slide area. Direct rescuers to their locations.
- Allow trained professionals to check the building foundation, chimney, and surrounding land for damage.