First, the city advised residents to run their water for five minutes before using it, to use only cold water for drinking and cooking, and to install lead-removing water filters. Then county officials issued an emergency advisory recommending that people not drink Flint’s water unless it is tested for lead or filtered.

And last Friday, after corroborating that lead levels had risen in some children, state officials called for the water to be tested at all Flint public schools and for stepped-up efforts to replace lead service lines; they also promised $1 million to provide filters.

Officials met here on Wednesday afternoon, and talks were underway, officials said, for additional solutions that could come as early as Thursday. Gov. Rick Snyder said on Twitter late Wednesday that he planned to make an announcement about the situation on Thursday morning.

Private groups have raced to donate bottled water to schools, where the water fountains are now shut off, as well as filters to families who cannot afford them. Saying “we’re just in a heck of a bind,” Robert J. Pickell, the Genesee County sheriff, began serving bottled water and food that need not be cooked in water to hundreds of inmates in the county jail. Some residents have begun washing their children and pets with bottled water.

And Flint’s mayor, Dayne Walling, who had attended a 2014 event to celebrate the switch to the new water supply, called for returning to the city’s old water supply and urged state officials to provide millions of dollars to help pay for it.