Canoe Chutes for Low-head Dams
In recent decades, there has been an increase in recreation on Illinois rivers and streams. Canoeing and kayaking are two of the activities that have become more popular. On many Illinois rivers there are low- head dams that are a hazard to canoeists and kayakers. Structures such as canoe chutes are necessary at dams to provide safe passage for boaters.
Although, many structures for kayak passage have been built at low-head dams in the western United States, few definite design guidelines for canoe chutes are present in the literature. Therefore, it has been necessary to do a physical model study for all or most of the existing structures. Physical modeling is expensive in both time and money. With the aim of eventually constructing canoe chutes at low-head dams in Illinois, the Illinois Department of Natural Resources asked the Department of Civil and Environmental Engineering at the University of Illinois to conduct a study of canoe chutes. The aims of the study were to understand more fully the three-dimensional flow in canoe chutes and to develop design guidelines for canoe chutes in Illinois.
As with previous studies on canoe chutes, a physical model of a canoe chute was built. However, to save time and money, numerical tests using the program, Flow-3D, were done on several design possibilities. The numerical tests were compared to the results from the physical model. An analysis of the canoe chute using two-dimensional momentum equations was performed in order to gain a fuller understanding of the flow in canoe chutes. Additionally, an empirical method was developed for predicting hydraulic jump behavior in canoe chutes. This method is important for applying the design guideline that only wave-type hydraulic jumps are safe in canoe chutes.