The Hillsboro Water Department is beginning a year-round unidirectional flushing program that city officials say will help improve the water system and prepare for the transition to a new water supply from the Willamette River.
A press release from the department says that the flushing program clears out water mains by pushing the water out through fire hydrants, a maintenance step that helps clear out sediment and other buildup.
“Sediment can build up in water mains and eventually affect the amount of chlorine in the water and impede water flow,” said Jessica Dorsey, Hillsboro Water Resources Division manager. “This can cause taste and discoloration issues and lead to reduced water flow for fire protection.”
Hillsboro is part of a $1.6 billion interagency project — the largest of its kind in Oregon — to tap the Willamette as its new water source, along with the neighboring city of Beaverton and the Tualatin Valley Water District.
The Willamette Valley Water Supply Program is currently on pace to complete its work in 2026, the organization’s website notes.
The flushing process in Hillsboro involves opening and closing water valves to isolate a specific section of water main, then drawing water from that section through above-ground hydrants. That water will then make its way into storm drains and will be treated.
Water customers will notice signs posted in the vicinity of the flushing areas several days before the flushing occurs.
Water service will not be disrupted during the flushing, officials say, so water customers should still be able to use their water.
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