Elevated water storage tanks are generally considered extremely beneficial to water distribution systems. These “floating” storage tanks reduce peak pumping rates, stabilize pressures, and increase reliability. However, elevated storage can be significantly more costly than in-ground storage (depending on pumping needs) and, if not designed and operated properly, can have a detrimental impact on water quality. As water quality is becoming an increasingly critical factor in water supply and distribution systems, it is crucial that potentially negative water quality impacts from elevated storage be recognized and eliminated. This paper highlights the impacts of elevated water storage