One state license, many local permits
Iowa's Plumbing and Mechanical Systems Board licenses plumbers and plumbing contractors across Iowa. Because that license works statewide, the same contractor can serve Ankeny one day and Ames the next, but the permit still comes from whichever city building office covers the address.
Rivers, aquifers and floods
Des Moines treats Raccoon and Des Moines river water, Cedar Rapids pulls from shallow wells along the Cedar River, and the Quad Cities draw on the Mississippi. Nearly all of it is hard, and farm-country nitrate is a recurring concern for river-based utilities. The floods of 1993 and 2008 swamped basements from Des Moines to Cedar Rapids, and heaters that sat underwater were usually replaced. MidAmerican Energy and Alliant Energy are the main gas and electric utilities. A soaked basement tank is covered under leaks, and Iowa homeowners pricing a new one can start with replacing a heater.