Annual Fall Hydrant Flushing Begins Monday, September 21 2026

Portsmouth, New Hampshire – The City of Portsmouth Department of Public Works Water Division begins its seasonal routine flushing of fire hydrants and water mains on Monday, September 21, 2026. Every hydrant in the City will be flushed, starting from the outskirts of the City working in. The flushing will take place for the next six weeks, Monday through Thursday, between 7 am and 11 pm.

The annual spring and fall flushing programs are critical for maintaining water quality throughout the distribution system by removing sediment buildup in both public and private hydrants in Portsmouth, New Castle, Rye, Greenland, and Newington. Crews open the fire hydrants, releasing water with enough velocity to carry sediment out of the pipes. Flushing locations are indicated by the presence of DPW Water Division vehicles with flashing lights.

Hydrant flushing can result in discoloration of tap water, but the water remains safe. Once flushing is completed in their area, customers can check their water clarity by running cold water to flush their plumbing systems. If the discoloration persists, customers should use the DPW Click ‘n’ Fix system to ensure a prompt response. 

Visit the City of Portsmouth DPW Water Division for more information.