With today’s heavy rains, the Big Pipe system that protects the Willamette River from most combined sewer overflows reached a suspenseful moment today.
As rainwater surged into the city’s combined sewer and stormwater pipes, the system filled to capacity, reaching 100 percent full at around noon.
People following the online Big Pipe Tracker saw levels staying at 100 percent for about an hour before slowly dropping to 98 percent by 2:45 p.m.
Reaching 100 percent usually means an overflow to the river. But no overflow occurred.
With more rain on the way, levels may change. But for now, the Willamette River remains sewage-free.
The public can continue to track this storm and view how full the Big Pipe is via the Big Pipe Tracker. If an overflow should occur, this news release will be updated and people will be advised to avoid contact with the river’s water for 48 hours.
The Big Pipe system refers to a series of improvements - from rain gardens and green street planters that allow rainwater to be absorbed naturally to the construction of giant pipes on both sides of the river and along the Columbia Slough to store and convey large quantities of flows to the Columbia Boulevard Wastewater Treatment Plant.
Source: Portland Bureau of Environmental Services