Oregon Public Broadcasting

Multiple government agencies are asking Oregonians to be cautious, around Oregon's waterways over the holiday weekend. The city of Portland is warning people not to touch the Willamette River.

Linc Mann with the city's Bureau of Environmental Services says recent rains have sent sewage into the river.

Mann: "That's because we have a combined sewer system, and when it rains, the storm water runoff flows into the same pipes in that system that carry sanitary sewage from homes and businesses. Those pipes fill to capacity and some of it overflows into the Willamette River, so there's a lot more bacteria."

Mann says if the rain abates, the river should be mostly clear of sewage in a day or two. 

Meanwhile, Clackamas County officials say they plan to watch out for boaters who have had too much to drink. And the county plans to enforce its alcohol ban on local rivers.