Seattle seawall raises climate change concerns for civil engineer

The new seawall along Elliott Bay is among the most expensive projects in Seattle history.

RELATED: Project taking shape at Seattle’s waterfront

The stated goal of the replacement seawall along Seattle’s waterfront is to “protect critical infrastructure and utilities while enhancing the habitat through this area.” The new seawall meets current seismic standards and “will last more than 75 years, serving as the foundation for projects transforming Seattle’s future waterfront.”

But will it be high enough to counter the rising water levels of global warming?

That was the question KTTH’s Todd Herman posed to civil engineer Jeff Juel. At its highest point, Juel said the current seawall is 16.1 tall, which is the same height as the one currently being built.

“You can actually go down to the waterfront and walk the waterfront and see where the new seawall ends and it meets the old sea wall. They’re the same height. Not even an inch. They really probably could have rationalized making it eight inches higher because that’s the magnitude of the sea level rise we’re going to see in the next century — eight inches. In 100 years, it will be 8 inches of sea-level rise, almost guaranteed.”

Juel explained that a tide gauge that has been operating since 1899 at the Coleman ferry dock shows sea level trends. Shows a pretty much straight line trend at 2.03 mm per year, which works out to 8 inches per century. He also pointed to the Seattle Department of Transportation’s blog that shows a graphic of existing tidal heights with future tidal heights, with 50 inches of sea-level rise, which is essentially the “worst-case scenario” by the year 2100. Juel doesn’t expect that scenario.

“Myself personally, 2.03 millimeters per year, stake my life on it,” Juel said. “It’s essentially what we’ve seen since 1899. There’s no acceleration in the rate of sea-level rise per that tide gauge. There is no acceleration in the sea level for any tide gauge for the East Coast or the West Coast.”

Watch the above video for a full explanation.