Citywide unidirectional waterline flushing to restart in Lacey

Large volumes of water will flow through gutter lines beginning Oct. 1, as the City of Lacey resumes its unidirectional waterline flushing program. 

The Lacey Public Works Water Operations Division will run the preventive maintenance cycle through May 2026, directing high-velocity flows across planned routes to dislodge minerals and sediment from more than 400 miles of pipe. 

Crews will open fire hydrants and blow-off valves in sequence to force water fast enough to strip deposits from inside the pipes. 

According to the city, discharges may appear cloudy or brown as they move along gutter lines into storm drains. Signs will be posted before work begins in each neighborhood. 

Residents are advised to run faucets for five to 20 minutes until the water clears before using it for drinking, cooking or laundry. 

Lacey began the flushing program in 2004.

"It takes nearly five years to complete one cleaning cycle of the entire city’s water distribution lines. Some parts of the water system require flushing more frequently and may need cleaning every year. Water quality sampling throughout the distribution system, helps staff determine which parts of the system need greater attention," the City of Lacey Public Works Department states on its web page about the issue.

The program avoids the summer months when customer demand is highest, running instead from October through May. 

In the 2025 Water Quality Report, Lacey reported 433 miles of waterlines, 4,344 hydrants, 15,700 water valves, 20 production wells and nine reservoirs. Testing in 2024 confirmed the city’s system was in compliance with U.S. Environmental Protection Agency regulations, meeting or exceeding all federal drinking water standards. 

For more information or service concerns, contact the Public Works Department at 360-491-5644.