Union Avenue Dam Boatchute Study
boater safety, channel, design, hydraulic jump, hydraulic models, intake, model studies, sediment sluicing, South Platte River
United States Department of the Interior, Bureau of Reclamation
Hydraulic jump-type energy dissipators are a safety hazard to recreational boaters. The Union Avenue dam constructed on the South Platte River in 1985 by the U.S. Army Corps of Engineers was studied to improve boater safety. One alternative was to construct a series of boatchutes each with a drop of 2 to 4 feet to handle the enter 15-foot head drop. The Colorado Water Conservation Board hired Wright Water Engineers to plan a series of boatchutes for the Union Avenue dam site. Reclamation built and tested a hydraulic model to refine designs of the boatchutes, to optimize boating flows, and to study sedimentation conditions at the city of Englewood's water intake structure. In addition, floodflows through the modified structure were studied. The model study resulted in the development of an improved boatchute design. A design procedure for employing the boatchute design at other sites was suggested. A modification to the Englewood intake structure is suggested which should improve sluicing of sediment while ensuring boater safety. The modified structure will pass the U.S. Army Corps of Engineers 100-year flood of 16,400 ft3/s without adversely affecting the present flood control channel of the river.