NATIONAL WEATHER SERVICE:
Landslide Hazards in Oregon Fact Sheet (1266 KB PDF)
DEBRIS FLOWS IN OREGON
Debris flows are rapidly moving landslides that can destroy everything in their paths. They can easily travel a mile or more, depending on the terrain. They typically contain boulders and logs transported in a fast-moving soil and water slurry down steep hillsides and through narrow canyons. A debris flow moves faster than a person can run.
Throughout the rainy season, the National Weather Service will highlight the potential for debris flows and landslides as part of a flood watch, for areas included in the flood watch. The flood watch will include this language: "LANDSLIDES AND DEBRIS FLOWS ARE POSSIBLE DURING THIS FLOOD EVENT. PEOPLE... STRUCTURES AND ROADS LOCATED BELOW STEEP SLOPES... IN CANYONS AND NEAR THE MOUTHS OF CANYONS… MAY BE AT SERIOUS RISK FROM RAPIDLY MOVING LANDSLIDES" (National Weather Service).
WHAT TO DO
Homes and roads at the base of steep slopes in or near canyon outlets are in the most hazardous locations. People living or traveling roads in such areas should stay clear of steep stream channels and steep canyon walls. People living in these types of locations should have a safe place to go when a warning is issued. Motorists should avoid all but emergency travel on roads below hazardous areas during warning periods.
What should you do when you hear there is a hazard of landslides in the area? Know that some areas are more hazardous than others when the danger of landslides is high. If there is a flood warning, stay away from the river. Also stay away from steep slopes during intense rainstorms. Knowing ahead of time where the danger areas around your home for potential landslides might be is the first step in being prepared.
Follow these steps:
Road maintenance personnel should also take heed of this increased hazard level and move out of the hazardous area along routes that avoid steep slopes if possible.
Cleaning up after landslides can also be hazardous. When it is wet outside, be careful when cleaning up the mess. A small mudslide can actually be part of a larger landslide. Cleanup should not be done until after the storm.
WHERE TO FIND OUT ABOUT WARNINGS
Once the potential for debris flow hazards is issued as part of the NWS flood watch, the National Weather Service relays this information through its emergency management alert and information network. The National Oceanic and Atmospheric Administration (NOAA) Weather Radio and OEM's communication systems are part of the network.
DOGAMI will provide additional technical information in response to media or public questions. For more information contact Ian Madin at (971) 673-1542.
Current Flood Watches, Debris Flow Alerts, Flood Warnings and Advisories for Oregon issued by the National Weather Service can be found online at: http://www.weather.gov/alerts-beta/or.php?x=1
NOAA Weather Radio Frequencies:
Office of Emergency Management Duty Officer: (503) 378-6377
Oregon Department of Geology and Mineral Industries: (971) 673-1555
Local radio and TV stations (not out-of-state cable TV)
Fossils, Minerals & Gems | Hazards | Field Offices | News and Events
Mineral Land Regulation and Reclamation | Oil, Gas and Geothermal
Nature of the Northwest Information Center | State of Oregon website
Oregon Department of Geology and Mineral Industries
800 NE Oregon Street #28, Suite 965, Portland, OR 97232-2162
(971) 673-1555, FAX (971) 673-1562
email us at DOGAMI
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