New technology helps families prepare for flood season

This winter is expected to be drier and warmer than average, due to an El Nino weather pattern. But that doesn’t mean the Northwest is out of the woods when it comes to flooding.

Brent Bowers with the National Weather Service says even though they predict less rain, precipitation is inconsistent during El Nino years.

“The last El Nino season was actually pretty busy,” Bowers said. “We had flooding every month of the year in Western Washington from October through March. But they were all pretty minor, so there wasn’t a lot of impact.”

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Flood danger will likely be the highest during December or November, which is the wettest month of the year.

And there are plenty of tools for families to prepare. Most counties allow people to sign up for text or email alerts, and distribute flood plain maps upon request so homeowners can gauge flood risk to their property.

New tools are also being released. King County has a free smart phone app that allows people to check river levels, and get flood stage alerts.

King County Flood District managers are also releasing a new interactive flood map for the Chehalis River next month. The map shows the impact of the river at different flood stages. That way, families can see what roads might be underwater to plan evacuation routes, what neighborhoods could be affected, and even how deep that water could be. Interactive maps for more rivers are in the works for the future.

The Army Corps of Engineers is also gearing up for the rainiest part of the year. Water management specialists are constantly watching storm forecasts and helping to manage dams around the region.

“We do flood risk management,” said Larry Schick, meteorologist with the Army Corps. “So when the big rains come and the rivers rise, we capture the water, store it, and keep the waters at bay downstream. And after the storm we allow the water to move out of the dam.”

Schick says it only takes 48 to 72 hours to fill up a reservoir. Then they have to let the water out again to prepare for the next storm. It’s a delicate balance. Letting too much water out during rainy seasons could spill water over the banks of rivers, especially in flood plain areas like Pacific or the Snoqualmie Valley. But letting too little out could mean flooding farther upstream.

“So we want to make sure everybody knows that, that flooding is still a possibility and on the table,” Schick said. “And it might even be caused by water that we let out. We’re going to do our best to do whatever we can to keep the water intact in the levees in the flood plain system without flooding homes, but it’s not a guarantee.”

Though last winter was dry overall, flooding devastated areas like Brinnon in Jefferson County. The hope is that good water management and new technology designed to help families in high-risk areas prepare, can prevent property damage or injuries.

“We’ve been doing river and weather forecasting for a long time,” Bowers said. “As the years have gone by, we’re getting better at it. But we’re still seeing people die because of flooding and other weather. And so one of the things we’re trying to go beyond just giving warnings but try to put things in a way that will get people to act when they need to.

“For flooding, this is one way to do it, besides giving them the flood warning. But now they can go and look and see where their house is on a map and see that it’s in this dark blue meaning my house might be under water.”