Eldorado Springs, a census-designated place in Boulder County, is the reigning champion in the “Best Municipal Water” category. Last year, Eldorado finished fourth. Several high quality water sources such as the reservoirs and streams in North Boulder and Middle Boulder Creek Watersheds, and diversions from the upper Colorado River via Carter Lake and Boulder Reservoir are what make the drinking water in the area one of the best in the country, the local government says.