Big Pipe

Heavy rain caused sewage to overflow into the Willamette River on Feb. 5, 2017.

(Stuart Tomlinson/The Oregonian)

Portland's sewer system couldn't handle Sunday's deluge.

The sewer overflowed for the third time this winter, the Portland Bureau of Environmental Services said in a press release, starting near the Ross Island Bridge and stretching downstream.

Earlier overflows happened on Thanksgiving Day and on Jan. 18.

Nearly 1.5 inches of rain have fallen in Portland, overwhelming the city's combined stormwater and sewage system at about 1:30 p.m.

The city warned against contact with the Willamette River for 48 hours after the overflow ends -- which hasn't happened yet. It's not yet clear how much has spilled, but the city said a typical spill is 80 percent storm runoff and 20 percent sewage.

Portland completed a $1.4 billion Big Pipe project to cut down on combined sewer overflows in 2011. The bureau said there were an average of 50 such overflows each year before the project was finished.

-- Rob Davis

rdavis@oregonian.com

503.294.7657