The morning of Saturday, March 22, 2014, began like any other near the town of Oso, Washington, about 60 miles from Seattle.
The residents of the Steelhead Haven housing development went about their lives as normal. Suddenly, there was a roaring sound, and several minutes later, a huge landslide engulfed the town.
Finding a Scientific Explanation
The Stillaguamish River Valley is no stranger to landslides, with a notable one happening once every 30-40 years. However, this landslide started high up and carried much more energy, making it extremely disruptive. This destructive force spurred Tim Starkk, a civil and environmental engineering professor at the University of Illinois, to figure out why.
At the end of their investigation, Starkk and his team identified several factors that came together to cause the landslide. With laser-imaging techniques, the team discovered that the valley was the site of several large landslides, making the one that occurred in 2014 not that unusual.
The first was a 2006 landslide, which left behind loose rocks and dirt. These then absorbed massive amounts of water from a heavier-than-usual rainy season.
The second factor was an increase in erosion due to logging on the mountain. Trees and plants play a huge role in keeping rocks and soil in place. When logging companies don’t take proper precautions when harvesting trees on sloped areas, it changes the way water soaks into the soil, making the ground unstable and vulnerable to erosion.
This suspicion later proved to be true. In 2016, survivors reached a $60 million settlement with the state of Washington. Part of the investigation revealed that the area around the housing development was historically unstable and aggravated by logging. The excessive logging led to increased erosion, which contributed to the disaster.
As climate change becomes more pronounced, so too will the unpredictable weather it brings. Sudden squalls and unseasonable rainfalls could bring about more landslides like the one in Steelhead Haven. It’s important that we act now to limit the effects of erosion and protect vulnerable areas from damage.
If you live close to or on a steep slope, it’s important to take steps to protect yourself. One of them most effective means of erosion control is to seed the slope with plants that have dense root systems. Though you can do the process by hand, hydroseeding is a quicker process with better soil erosion control.
Hydroseeding works by spraying a slurry of fertilizers, seeds, moisture retention polymers and other ingredients onto the slope. The slurry absorbs excess water, and the fertilizers provide extra nourishment for the seeds, allowing the plants to quickly establish themselves on the slope. As the plants grow, they provide natural water control while locking soil and rocks into place.
Hydroseeding is a versatile technique, and it works as well on roadsides as it does in backyards. Some companies offer organic slurries, free from potentially polluting fertilizers. Even better, hydroseeding can establish plants on slopes with extreme angles, up to 90 degrees. However, after 45 degrees, you’ll have to use a yute mesh to stabilize the slurry.
Thanks to climate change, we may only see more natural disasters in the future, like the landslide at Steelhead Haven. Though some are outside of our control, landslides are preventable to a certain extent. Hopefully, companies will learn from this example, and realize that careful use of the available resources, as well as replacing those that are used, goes a long way toward protecting the surrounding areas.
Written by Kayla Matthews, Productivity Bytes