Portland’s Big Pipe hit 100% capacity Thursday after heavy rains, triggering a combined sewer overflow advisory that remains in effect for the Willamette River.
The overflow began about 4:20 p.m. Thursday after almost 1.5 inches of rain fell in Portland over about 13 hours. The Big Pipe remained at capacity until about 1 a.m. Friday.
People should avoid contact with the river downstream of the Ross Island Bridge and refrain from river recreational activities in that area until 48 hours after the end of the overflow. That would be about 1 a.m. Sunday.
The Big Pipe’s capacity dropped on Friday nearly as quickly as it had risen Thursday. It was back down to 47% capacity by 9:30 a.m. Friday.
Portland’s Big Pipe project, its biggest-ever public works project at $1.4 billion, was completed in 2011 and has reduced combined sewer overflows to the Willamette River by 94% and to the Columbia Slough by 99%, the city says. Overflows used to happen about 50 times a year but now are down to an average of about four per year.
Track the capacity of the Big Pipe here.