STORAGE BASIN FOR REDUCING NONPOINT SOURCE CONTAMINANTS

A temporary storage tank (100) for reducing non-point pollutants according to the present embodiment comprises: a chamber (110) for storing a fluid; an inlet (120) formed on the chamber (110) to introduce the fluid; a first outlet (130) formed on the chamber (110) to discharge the fluid; a second outlet (140) formed on the chamber (110) to be provided above the first outlet (130) and discharging the fluid; and a mixing prevention partition (150) provided between the first outlet (130) and the second outlet (140) and having one end coupled to the inner wall of the chamber (110) to be rotated and the other end coupled to a floating body (150a), wherein when initial rainwater is introduced into the inlet (120), the mixing prevention partition (150) is raised with the floating body (150a) by the buoyancy of the initial rainwater so that rainwater after the initial rainwater is drained through the second outlet (140) along the raised mixing prevention partition (150).