As snow melts it increases the risk of landslides across Washington state. The increased threat in western Washington lowlands below 1,500 feet extends through Friday, according to the U.S. National Weather Service.
A landslide occurs because the force of gravity becomes stronger than the internal strength and friction of the material of a hillside, such as soil, rocks and trees.
Melted snow adds more water to a hillside, and the added weight increases the risk of a landslide. Water can make the material weaker which makes it easier for gravity to move it downhill.
Here are few ways you can identify areas with an increased landslide risk:
1. Tilting of trees, especially evergreens, on slopes
2. Formation of cracks in yard, driveway and sidewalk foundation
3. Sudden difficulty opening or closing doors or windows
4. Sagging utility lines and leaking or broken water pipes
Washington state is one of the most landslide-prone states in the country, according to the state Department of Natural Resources. The Washington state Department of Transportation budgets $15 million a year for landslides that spill onto state roads.