Issues and Research Needs Related to Hydraulics for Spillways for State Regulated Dams

Results of a survey conducted for the NDSP Hydraulic Research Workshop, August 26 & 27, 2003, conducted by the Bureau of Reclamation.

Questions:
1. Does your state regulate dams with the following types of spillways? (-Corrugated Metal Pipe and Riser -PVC Siphon Pipe -Concrete Pipe and Concrete Riser -Earth Channel Spillway -Rock Spillway -Reinforced Concrete Chute -Ogee Weir -Labyrinth Weir -RCC Stepped Spillway over an Earthfill Dam -RCC Stepped Spillway in the Abutment -RCC Stepped Spillway on a RCC Dam -Gated Spillway -Fuse Plug Spillway -Run of the River Spillway -Gabion Basket Spillway -Rock Rip Rap Spillway -Concrete Block Spillway / Overtopping ( cabled or individual blocks) -Other, Please List.)
2. With the PVC siphon spillways in your state, are there multiple pipe installations? What is the largest diameter? If known, the maximum height of the vertical drop from the control section to the outlet.
3. Is ice / freezing of the reservoir an issue with the operation of the spillways on your regulated dams? Does it affect the hydraulics of the spillway? Do you have enough information on how ice affects the hydraulics?
4. Do you have concerns about skimming flows causing hydraulic jumps in stilling basins on stepped spillways during high flow events?
5. Do you have questions about how the hydraulics work with any of these spillway applications listed in number one?
6. Have you and your staff had adequate training to evaluate how your regulated spillways operate under all loading conditions?
7. Anything about the hydraulics of these spillways that need further research?

The ASDSO surveys archive is available to members through the members only section of DamSafety.org