SETTLING POND

A settling pond with high settling efficiency is provided to prevent water pollution by controlling density current such that sludge on the bottom of the settling pond is not floated, and increase settling efficiency by controlling the retention time of the supernatant according to turbidity of supernatant and particle distribution of floc. A settling pond(140) with high settling efficiency comprises: a settling pond body of which one side is connected to a flocculation pond(12) through a baffle wall(130) such that a fluid flows between the settling pond and the flocculation pond, into which floc formed on flocculators(121) flows through the baffle wall such that the floc is settled by gravity, and which has an overflow weir(150) formed on the other side thereof to discharge supernatant to the overflow weir; temperature sensors(240-1,240-2) formed on upper and lower portions of the baffle wall to sense temperatures in a top layer part and a bottom layer part of water flown in through the baffle wall; a fluid flow control unit(200) installed within the settling pond body and submerged into water of the settling pond body or floated on the water thereof to control a flow of water that flows along the settling pond body; and a control part(400) for calculating a difference between temperature values sensed by the temperature sensors to control the operation of the fluid flow control unit according to the temperature difference.