Weeks of heavy rain in the Pacific Northwest have wreaked havoc on roads and structures. Particularly troubling are the massive mudslides which hit Washington State, leaving108 missing and at least eight dead and destroying 30 homes. According to the New York Daily News, “The rescue mission was halted as darkness set in on Sunday because conditions were deemed too dangerous.”
As search and rescue efforts continue, we would like to resume our severe weather series by focusing this week’s blog post on one of the associated risks of severe weather such as rain and snow—mudslides. Out of respect for the victims and the missing, I will eliminate my typical “firedog-isms.”
Facts about Mudslides
- Occur when masses of rock, earth, or debris move down a slope.
- Can accompany heavy rains or follow droughts, earthquakes, volcanic eruptions or fast snowmelts.
- May result from rapidly accumulating water which saturates rock, earth and debris.
- Usually start at the top of steep slopes.
- Slopes which are particularly vulnerable include any area where wildfires or human modification of the land have destroyed vegetation, during and after heavy rains.
- In the U.S., landslides and debris flows result in 25 to 50 deaths each year.
- Associated hazards include broken electrical, water, gas, and sewage lines that can result in injury or illness; and disrupted roadways and railways that can endanger motorists and disrupt transport and access to health care.
- The consistency of debris flow can range from thin or thick mud to rocky mud that can forcefully carry large items.
- When flows reach flat ground, the debris typically spreads over a broad area, and can accumulate in thick deposits that can wreak havoc in developed areas.
- Every year, landslides in the U.S. cause roughly $3.5 billion in damage.
- Mudslides can travel several miles from their source, growing in size as they pick up trees, boulders, cars and other materials.
- Steep slopes and areas at the bottom of slopes or canyons;
- Spots where landslides have occurred before.
- Slopes that have been altered for construction of buildings and roads;
- Channels along a stream or river; and
- Areas where surface runoff is directed.
How to Prepare for a Mudslide
- Recognize landslide warning signs before they happen so you know what to do when they happen.
- Before the first raindrop falls, assume that steep slopes and areas burned by wildfires are vulnerable to landslides and debris flows.
- Contact local authorities to help determine whether landslides or debris flow have occurred previously in your area.
- Develop emergency and evacuation plans for your family and business.
- Find out about local emergency and evacuation plans, so you’ll know where to go and what to do if you are caught in a mudslide.
What to do During a Mudslide:
- Once the storm starts, look for tilted trees, telephone poles, fences, or walls, and for new holes or bare spots on hillsides.
- Avoid river valleys and low-lying areas.
- Stay awake and alert.
- Watch TV or listen to the radio for warnings about intense rainfall and for information and instructions from officials.
- Be aware of sudden increases or decrease in water level on a stream or creek that might indicate debris flow upstream. Remember; a trickle of flowing mud may precede a larger flow.
- Listen for rumbling sounds that might indicate an approaching landslide or mudflow.
- If you are out and about in a storm, be alert while you’re driving. Roads may become blocked or closed due to collapsed pavement or debris.
- If landslide or debris flow danger is imminent, quickly move away from the path of the slide.
- Evacuate! Get out of the path of a debris flow. Move to high ground, away from the path. If rocks and debris are approaching, run for shelter and take cover.
- If you can’t escape, curl into a tight ball and protect your head.
- Don’t forget about your neighbors. They may not be aware of potential hazards. Advising them about potential threats could save their life.
How to Recover from a Landslide
- Stay away from the mudslide site, since flooding and additional slides may occur after the initial landslide. Floods can follow landslides and debris flow because they may have occurred as a result of the same event.
- If it is possible to do so without entering the path of the mudslide, check for injured or trapped people near the affected area.
- Listen to the radio or TV for emergency information.
- Report broken utility lines to authorities.
- Check the building foundation, chimney, and surrounding land for damage. Damage to foundations, chimneys, or surrounding land may help you assess the safety of the area.
- Replant damaged ground as soon as possible since erosion caused by loss of ground cover can lead to flash flooding and additional landslides in the near future.
- Seek advice from a geotechnical expert for evaluating landslide hazards or designing corrective techniques to reduce landslide risk. A professional will be able to advise you of the best ways to prevent or reduce landslide risk, without creating further hazard.
When a disaster strikes, prior planning and clear decisive action can help save lives. The best way to prepare for severe weather is to be aware. The RJWestmore Training System by Universal Fire/Life Safety Services is a convenient and affordable solution to all of the training needs of your building(s). Choosing our service cuts property management training-related costs by 90% and saves you over 50% compared to conventional training! More importantly, IT SAVES LIVES.