Advisory Combined Sewer Overflow Released from Elk Rock Pump Station

A combined sewer overflow (CSO) advisory has been issued for the Willamette River after a release of approximately 5,000 gallons from the Elk Rock Pump Station. The release began at midnight on November 28, 2025, due to a PGE power outage that started around 11:30 PM the previous evening. Officials warn the public to avoid contact with the river in the affected area during the overflow and for 48 hours after it ceases, citing increased bacteria levels. Recreational activities, including swimming and boating, are not advised during this time. The Elk Rock Pump Station is located at 11875 SW Riverwood Rd, about a quarter mile north of Elk Rock and Spring Park Natural Area.

Portland's Big Pipe Project has effectively reduced CSOs to the Willamette River by 94% and by 99% to the Columbia Slough, showcasing the city's efforts to manage stormwater and sewage. Overflows are generally rare, occurring mainly during heavy rain or snowfall. Residents can track the overflow in real time via the Big Pipe Tracker.