The tracker shows how the Big Pipes fill up during wet weather. Levels will rise as two giant pipes on either side of the Willamette River collect, store, and send a mix of stormwater and sewage to the City’s wastewater treatment plant. Before the project’s completion in 2011, that mixture would have overflowed to the river. Today, overflows are rare, and the river is almost always clean enough for river recreation.
Current CSO Advisories: No advisories are in effect.
CSO Advisory Notifications: If a rare CSO does occur, be one of the first to know by subscribing to our Combined Sewer Overflow Advisories email notification list.
Track Levels Now
Data are updated every 15 minutes, with up to a 45-minute lag time.
Track Levels over 72-hours
The Details
Levels are at 0-5%
On most days, you will see that Big Pipe levels are low or even zero. That’s because Portland’s regular network of more than 2,500 miles of pipes has enough capacity to send all sewage and stormwater to the treatment plant. During these days, plant operators may use the Big Pipes as part of daily operations, so you may see the level up to 5 percent full at times.
Portland's green infrastructure (trees, rain gardens, and wetlands) provide additional natural stormwater solutions—letting plants and soil absorb rainwater, and reducing the amount that gets sent into pipes.
During heavier rains
You will see the level rise on this graphic, reflecting how full the Big Pipes are, and how much combined sewage and stormwater is being prevented from reaching the Willamette River. The amount you see is sent to the treatment plant. Before the Big Pipe Project's completion in 2011, that amount would have overflowed to the river. Indeed, overflows used to occur regularly—about 50 times a year.
How much volume can the Willamette River Big Pipes hold? Up to 100 million gallons of sewage and stormwater at any one time. So, for example, if the graph shows 15 percent full, that roughly represents 15 million gallons that are NOT going into the river, 30 percent full would mean 30 million gallons, etc.
During severe storms
During severe storms, the Big Pipes may approach capacity. If levels reach 100%, an overflow is occurring. These incidents are rare (an estimated four times a year), and Environmental Services will issue a combined sewer overflow advisory warning the public to avoid contact with the river for 48 hours.