MI conducting hydrant flow testing and water-main flushing

Published 10:30 am Tuesday, July 7, 2026

For the next three Tuesdays in July, city of Mercer Island crews will be conducting routine hydrant flow testing and water-main flushing in the south end of the South Mercer Playfields, west end of Aubrey Davis Park and near the Park & Ride and 80th Avenue Southeast.

Along with testing on July 7, 14 and 21, there may be further testing into early August, according to the city, adding that crews will post notices on signs along neighborhood streets during testing.

Crews are asking residents to limit their water use between 9 a.m. and noon during testing in their area.

“Reducing demand during these hours helps maintain stable pressure and minimizes the chance of cloudy or discolored water coming from household taps. If discoloration does occur, it is temporary and should clear after running cold water for a few minutes,” the city said, adding that residents may witness water running along the streets during the high-speed hydrant flushing.

The city added that the scheduled maintenance activities help ensure reliable water pressure for firefighting and improve long-term water quality by clearing out mineral buildup inside the system.

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