As Flint has shrunk, its network of water pipes built for a much larger metropolis has deteriorated. With fewer customers, water sometimes languishes in the system, becoming discolored. Moreover, water bills in Flint are far higher than those in neighboring communities. Officials say the switch away from Detroit water saves the city $12 million a year.

“It’s a very sore point, particularly when you have a population with a high degree of low-income folks,” Mr. Ambrose said. “To me, the conversation we need to be having is, how do we lower those rates?”

Some residents say they would rather not debate the cost until they are confident that the water is safe. When fecal coliform bacteria showed up in parts of the city last summer, residents were told to boil their water before using it. Officials addressed the issue by pumping extra chlorine into the system, but in solving one problem, they created another.

The high chlorine levels led to elevated levels of total trihalomethanes or T.T.H.M., which required another public notice in January. Residents will again receive a notice of elevated T.T.H.M. levels in the mail later this month, Mayor Dayne Walling has said. Long-term consumption of water with high T.T.H.M. levels can lead to liver or kidney troubles and an increased risk of cancer, according to the Environmental Protection Agency.

Some here say Flint had been on the verge of a rebound when the water problems started. The walkable downtown area, just steps from the University of Michigan’s campus here, is now home to the Flint Crepe Company and other new restaurants. And perhaps most significant, the emergency manager was expected to leave office in the coming weeks, handing power back to the elected mayor and City Council.