DETROIT — A top aide to former Michigan Gov. Rick Snyder took the stand in an Ann Arbor courthouse this week and described his frustrations with state agencies during the height of the Flint water crisis in 2015. As Flint residents and clergy raised alarm bells about stinky, discolored water flowing from their pipes, Dennis Muchmore said Tuesday their concerns were effectively ignored by the state government. He wrote as much in a July 22, 2015, email to then-state Health and Human Services Director Nick Lyon: “These folks are scared and worried about the health impacts and they are basically …