September 22, 2015

Making sure our drinking water system is ready for the “Big One” is a top priority for the Portland Water Bureau.

Later this year, the bureau will seek Council approval to move forward with two big projects to protect our drinking water from the damage of a major earthquake: the Washington Park Reservoir Improvements Project and the Willamette River Crossing.

Both projects are critical to ensuring that our Bull Run water can travel to Portland’s west side, which includes all of downtown. The Willamette River Crossing project will install a new, seismically resilient pipe under the riverbed, and a new underground reservoir at Washington Park will be able to safely store that water.

This morning, the Water Bureau shared important project updates at a City Council work session, including current designs, cost estimates, and timelines.

We recently learned that the Washington Park site is much more complex than engineers 100 years ago realized. Constructing a new, seismically resilient reservoir is challenging and requires essentially building a second structure—or fortress--around the reservoir itself, protecting it from both landslides and earthquakes.

Staff outlined some creative engineering methods to address these seismic and landslide challenges, including a “shoring” wall that will let the reservoir be flexible and move if the ground is shaking.

These proposed investments will strengthen the City’s seismic resilience, and ensure the Water Bureau can continue to deliver high-quality, safe, and reliable drinking water at all times – even after the “Big One.”

Seismic Resilience Projects Update

Portland Water Bureau

Portland's Washington Park reservoir project could cost $170 million

Andrew Theen in The Oregonian