Winter floods highly likely

It’s not the dikes and levees that have Snohomish County’s emergency planners worried.

They’re more concerned about the weather.

Michael V. Martina / The Herald Community Emergency Response Team volunteers and urban planning students from the University of Washington tour dikes around Snohomish County, including a section of the French Creek Flood Control District in Snohomish.

Flooding spurred by hard rain is a real possibility this year, said Mike McCallister, planner for the Snohomish County Department of Emergency Management.

The Pacific Northwest is in the midst of a normal weather year, which means little snow, significant rain and a greater likelihood of flooding.

“We have to be prepared,” McCallister said. “Statistics say we’ll have a greater chance this year. We always expect flooding. At some point in the year, we’ll have enough water to go over the riverbank someplace.”

Floods roll through local valleys every three to 10 years. Most of the flooding happens when a series of storms, often with warming temperatures, bring heavy rain to the mountains, triggering early snow melt.

The largest floodplains are in the Snohomish, Skykomish, Snoqualmie, Stillaguamish and Sauk river basins.

The last major flood here was two years ago, when rising water wreaked an estimated $5 million in damage along the Snohomish, Stillaguamish and Sauk rivers.

On Saturday, McCallister led a group of county emergency workers on a tour of the floodplains along the Snohomish and Skykomish rivers.

For the most part, the county’s dikes and levees are in good shape and should hold up fine in high water, he said.

Some dikes on the lower Snohomish River are in need of work, but they are in areas where few people live, so the risk is minimal, he said.

Many of the problems the tour highlighted are man-made.

In Monroe, McCallister pointed out several homes built atop ground that could lose stability in a flood or earthquake.

Unless the homes are built on pylons deep enough to reach bedrock, which is 60 feet down in some places, the buildings could sink, McCallister said.

The tour also visited a Sultan neighborhood where emergency officials fear homes could be damaged by landslides during heavy rains.

People should heed warnings and leave their homes during major floods, McCallister said. The only two local deaths during floods over the past 15 years were people who ignored signs and attempted to drive onto flooded roads.

Although the Department of Emergency Management keeps regional authorities abreast of potential flood threats, it’s up to the Snohomish County Sheriff’s Office and the various cities to issue evacuation orders.

“There’s no way we can go in and drag people out of their homes,” McCallister said. “If they elect to stay there, the best we can do is tell them what the risk is, and to send us a smoke signal if their house starts to go away.”

To make sure that police and emergency crews can coordinate their efforts during disaster, county officials have obtained radios that share common frequencies. The equipment was purchased using grant money from the federal Department of Homeland Security.

“We are a multi-agency coordinating body,” McCallister said. “The primary function for us is to acquire and distribute the resources to the incident commanders out in the field.”

Those who live near flood-prone areas need to play a role, too, McCallister said.

“People need to pay attention to the flood forecasts and National Weather Service issues,” he said.