Abstract: The flushing apparatus comprises a reservoir for storing liquid, the reservoir having an outlet end movable between a raised position where liquid accumulates in the reservoir, and a down position where liquid stored in the reservoir is flushed out; a counterweight for producing an effect of urging the outlet end of reservoir toward the raised position; a reservoir ballast for cancelling the effect of the counterweight when the liquid stored therein reaches a predetermined amount; a channel for channelling a liquid into an inlet of the ballast when the outlet end of the reservoir is in the raised position; and a means for preventing an overflow of the outlet end of the reservoir. There is also provided a method for flushing liquid.