Abstract: A drain cover assembly includes a closure device operable so as to close and open a drain hole in a cover plate of a drain cover unit. The closure device includes a pivot arm having a mounting portion connected pivotally to the cover plate, a flow control portion extending from and disposed on a first side of the mounting portion and registered with the drain hole, and a weighted portion extending from and disposed on a second side of the mounting portion and having a weight sufficient to overcome the weight of the flow control portion so as to cause the pivot arm to pivot from an open position to a normal closed position. The pivot arm pivots to the open position when the flow control portion is subjected to an applied load through the drain hole that is sufficient to overcome the weight of the weighted portion.