a self - cleaning , low - maintenance , water - saving automated animal watering device is provided which includes a watering tank moveable between a lower , water - full condition and an upper , water - low condition . preferably , one end of the tank is pivotally supported by a pivot shaft , while the other end of the tank is biased upwardly via a lower lift spring . the device also has a water fill assembly operably coupled with tank to selectively fill the tank when needed , and a drain valve assembly also coupled with tank in order to completely drain the tank on a periodic basis . a control assembly is coupled with at least the tank and drain valve assembly , and is operable to actuate the drain valve assembly after a predetermined number of movements of the tank between the elevated and lowered positions thereof .