The Des Moines Water Works (DMWW) is a publicly owned, municipal water utility founded 1871 in Des Moines, Iowa, which provides water to half a million residents of the greater Des Moines metropolitan area. As of 2017, it has three treatment facilities.In March 2015, the DMWW board sued three Iowa counties for violating the Clean Water Act with high nitrate discharges, which contribute to hypoxia in the Gulf of Mexico.