Mayor's Office

City of Flint October 22, 2021 Update: Secondary Water Pipeline

FLINT, MI —The Department of Public Works began facilitating 95/5 water increment combining/blending to the secondary water pipeline (Genesee County Drain Commissioner or GCDC) on Monday, August 23, 2021. The process of combining the primary and secondary water sources was required to complete necessary repair work to the City’s primary water pipeline.

Phase III of the City’s incremental water blending process toward reaching 50 percent for the secondary GCDC water pipeline, and 50 percent for the primary water pipeline (Great Lakes Water Authority or GLWA) began on Monday, October 11, 2021.


• The transmission line from GCDC will be flushed on Monday, October 25, 2021 in order to clear the water pipelines before Phase IV of blending begins.

Phase IV, which will increase the incremental water blend to 75 percent for the secondary GCDC water pipeline, and 25 percent to the primary water pipeline (Great Lakes Water Authority or GLWA), is scheduled to begin on Tuesday, October 26, 2021.

• Decisions on future incremental water increases will be based on the monitoring data collected.

All protocols are in adherence with the State of Michigan Safe Drinking Water Act, and the City’s agreement with its primary water supplier, GLWA, will continue to be followed.

Important resident reminders:

• The 5 percent of water that will flow from GCDC during the connection will be increased to increments of 25 percent until 100 percent is reached. The process will include testing and monitoring along the way to ensure water quality. This increment increase is needed to facilitate the system upgrades, quality assurance and monitoring necessary to create a safe, ongoing connection to the backup water system. 

• During the connection and blending of water, safeguards will be in place to initiate a full return to water from the current GLWA line within 24 hours, in the event of an unanticipated water quality issue.

• When the valve repair work is completed, Flint’s water will once again flow from the primary water pipeline connection to GLWA.

• To keep the water, pipes, valves and other hardware in the secondary pipeline fresh and ready to use in an emergency, about 5 percent of Flint’s water will continually flow through that pipeline.

• Additional monitoring will continue throughout the incremental water increase process, valve replacement work on the primary water delivery system (GLWA), and during all major infrastructure projects. Monitoring results are available on the State of Michigan’s website at

• Informational meetings and open public comment will continue to be scheduled to provide residents with updates on ongoing and all future water infrastructure projects, which are also posted on the City of Flint’s webpage at

For water emergencies or issues with water service, residents can call (810) 766-7202 [water] and (810) 766-7079 [sewer]. This line is monitored 24 hours a day.

For non-emergency questions or concerns, residents can email [email protected]. This email is monitored by the DPW department staff.

• Mayor Neeley will continue to provide weekly community updates on WFLT 1420 AM and on Facebook on Saturdays.

The City of Flint will continue to provide residents with updates on water infrastructure projects as information becomes available.

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