A rotating irrigation screen apparatus includes a frame, a panel coupleable to the frame, a drum, and a belt tensioner. An upper portion of the frame may have a mounting bracket that receives a motor/gear box. The drum may include one or more screen panels that may be removably attachable. The belt tensioner may include a first bolt that receives a first bracket with a belt guide roller. The belt tensioner may be configured to interact with the motor, the belt, and the drum. The belt tensioner may increase or decrease the tension of the belt that wraps around the drum.