Rains are here, landslides are coming: How to prepare

November can be the wettest month of the year in Seattle, and along with all that rain comes an annual headache for the city: landslides.

The soils become supersaturated with November and December rains — bad news for some 18,000 Seattle homes that are in landslide zones, said Bill Benzer, the city's landslide expert.

At a home in West Seattle Monday, Benzer offered tips on ways those homeowners can minimize their risks — from keeping their gutters clean to planting vegetation.

Already this month, 3.25 inches of rain has fallen at Seattle-Tacoma International Airport, exceeding the seasonal average by 0.68 inches. More rain is expected throughout the week — and possibly even snow or mixed rain and snow come Saturday, said National Weather Service meteorologist Dennis D'Amico.

Benzer said 45 percent of the landslides occur in January, when the fall rains have soaked the soil, and that 84 percent of those slides have some kind of human component — whether it's inadequate landscaping or a leaky pipe.

He recommended:

• Growing vegetation that can stop erosion.

• Cleaning storm drains to prevent clogs and water build up.

• Putting in a catch basin to catch water runoff.

• Inspecting gutters to make sure they're clear.

• If you cut down a tree, leave the stump to protect the soil and keep fill and yard waste off slopes.

• And if you notice trees starting to tilt, contact an engineer to see if there is weakened soil.

Since the devastating landslide season of 1996-97, which involved more than 300 landslides in Seattle, the city has taken steps to reduce the slide potential.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com

Staff reporter Jill Kimball contributed to this report.