Oregon Precipitation

Oregon has received heavy precipitation all winter, with Salem, Eugene, Portland, and other cities across the state breaking their previous rainfall records in the same day. As well as inducing the expected landslides and road closures, this increase in water has also caused a sewage overflow into the Willamette River and is suspected to have prompted the presence of a parasite in Portland’s primary water supply.
On Feb. 5, heavy rain caused sewage to spill over into the Willamette River after the estimated 2.49 inches of rain in downtown Portland overwhelmed the city’s sewer system. On the same day, Salem discharged almost 57 million gallons of raw sewage into the Willamette River to avoid sewage flooding. Four days later, on Feb. 9, Salem released an additional 14.7 million gallons of sewage due to the continued rainfall. More sewage has been dumped into the river since then, including another 1.18 million gallons on Feb. 16.
“I understand that it’s necessary to dump the sewage after all the rain we’ve had,” Maddie O’Donnell ‘19 said, “but I think it’s probably doing a lot of harm to the river. The Willamette River has not been known for its cleanliness in the past.”
Rain levels have been high in Oregon since before January, and in an interview Mike Stuhr, director of the Portland Water Bureau, told Oregon Public Broadcasting [OPB] he believed this increase in rain could have contributed to the parasite found in Portland’s water supply.
Although the parasite cryptosporidium had been found in Portland’s primary source of water-the Bull Run watershed-more than once, the Portland Water Bureau announced on Feb. 12 that the city had decided to distribute water from wells surrounding the Columbia River while the parasite is investigated.
“We thought it would be in the best interest of all if we switched to using the groundwater system,” Stuhr said in an interview with OPB in February. “We’re going to continue to monitor the water up in Bull Run lakes and study it some more.”
Cryptosporidium is often found in animal feces, so Stuhr’s theory, according to OPB, is that the increased rainfall caused more animal feces to run into Bull Run’s reservoirs-carrying the parasite with them.