Gated Spillway for Raystown Reservoir, Juniata River, Pennsylvania: Hydraulic Model Investigation

Abstract : Model investigation of the two-bay spillway for Raystown Dam was concerned with flow conditions in the spillway approach, over the weir, and in the chute; performance of the flip bucket at the lower end of the chute; and the adequacy of riprap on the left bank across the Juniata River from the spillway discharge channel. Of primary concern were severe surges at the spillway gates that had been observed in models of other projects where operating conditions were similar to those at Raystown spillway. Tests were conducted in a 1:60-scale model that reproduced 1000 ft of upstream approach channel, the entire spillway including weir, chute, and flip bucket, and about 1000 ft of the downstream channel. Surges at the spillway gates did not occur under any anticipated operating conditions. Except for a minor deficiency in the height of a portion of the chute walls, all elements of the structure performed essentially as planned by the designers. (Author)