Placer Creek High-Velocity Channel and Debris Basin at Wallace, Idaho. Hydraulic Model Investigation.
Final rept. Jul 79-Oct 81,
ARMY ENGINEER DIV NORTH PACIFIC BONNEVILLE OR DIV HYDRAULIC LAB
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A 120 scale model of the Placer Creek high-velocity channel and debris basin was used to determine the adequacy of the proposed design. The model reproduced the entire 3,875-foot-long, concrete-lined channel the 420-foot-long debris basin and approximately 620 feet of the South Fork Coeur dAlene River at the exit of Placer Creek. The original-design debris basin was ineffective. Satisfactory flow conditions in the basin were achieved when the basin was deepened and a 23-foot-high drop structure was added at the upstream end to dissipate energy of the incoming flow. The model verified that the basin design was effective in trapping debris in the basin. The original channel design proved to be satisfactory except in one area where two short reverse curves caused unacceptable waves in the channel. This condition was remedied by realining the channel using a straight-line transition between the PC of one curve and the ST of the other curve. Moveable bed studies showed that high Placer Creek discharges would develop a large scour hole in the South Fork Coeur dAlene River at the exit of the high-velocity channel. Although not tested in the model, a grouted riprap section was included in the prototype to minimize the scour potential. Author
- Hydrology, Limnology and Potamology
- Civil Engineering
- Structural Engineering and Building Technology