When Seattle's big storm hits, let streets become rivers

Seattle doesn’t get hurricanes like the ones that recently dumped trillions of gallons of water on Texas and Florida.

But scientists say in this era of climate change, Seattle should expect more intense rainstorms — ones strong enough to cause landslides, sewage overflows and drownings. And there’s more we could do to prepare for them.

The good news is that Seattle already has done a lot to prepare for heavy rains. The bad news is that, given climate change, nature has a way of throwing bigger storms at cities than they expect.

Steve Moddemeyer is a principal with CollinsWoerman, an architecture and planning firm in Seattle. He says water could overwhelm us. “We saw that in Houston, when I-10 turned into a river," he said.

It was an accidental river, so the water caused a lot of damage. But water needs a place to go.

If you plan for it, streets are a great place to put the overflow. Streets like that are called "blue streets."

Which brings us to Brooklyn Avenue in the University District. It’s long and wide. It’s not too steep, and it terminates at a small park at the Ship Canal.

Here’s how we could turn it into a blue street: We turn the edges of the street into something that looks like the banks of a river, with plants and spongy soil.

Then we waterproof the road bed itself, sealing off manholes and underground electrical boxes.

When the 100-year storm hits us, for one day, Brooklyn Avenue turns into a slow-moving river, three and a half inches deep from curb to curb.

“When it’s flooding at this high level, people will come down and look at it because it will be really cool to see this water running down," said Moddemeyer, "I don’t think anybody will be fishing in it, so that’s one limitation, I guess.”

Want to learn about more strategies like this? Come to KUOW's next Urban Innovations event, How Can We Increase Seattle's Climate Resilience?

Tuesday, September 19 at 6 PM - 7:30 PM, Seattle Public Library, downtown branch, free admission