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The City of Portland, Oregon

Nick Fish (In Memoriam)

City of Portland Commissioner

phone: 503-823-3589


1221 S.W. 4th, Room 240, Portland, OR 97204

Unidirectional flushing

December 17, 2014

The Portland Water Bureau works hard throughout the year to provide us with some of the best drinking water in nation.

One of the ways the Water Bureau maintains our high quality water is by unidirectional flushing (UDF). 

Over time, tiny bits of sediment and organic matter from the Bull Run watershed settle and accumulate in the bottom of pipes.  Unidirectional flushing forces high-speed water through pipes to remove those sediments.  Flushing crews temporarily close valves to isolate sections of pipe, and water is directed through an open fire hydrant. 

This year, over 43 miles of water mains have been flushed in southwest and northwest Portland. 

Check out the Water Bureau’s website for more information.