FLOOD06919

• County: Arapahoe
• Stream Name: South Platte
• Basin: South Platte
• Title: Union Avenue Boat Drop
• Date: 1/1/1983
• Prepared For: CWCB
• Prepared By: CWCB
• Floodplain - Doc Type: Easement

DRAFT

This modification will reduce construction costs since raising the sluice wall and reinforcing it to
withstand differential loading forces would have been costly.

Rlprtlp end chen"el stebillty. - The riprap on the first rock embankment downstream of the Union
Avenue dam was stable for all flows studied. The upstream face of the embankment was mainly
a deposition area. After the sand reached the elevation of the crest (5288 feet), it passed over the
embankment into the next pool. Riprap on the downstream face was stable through the 100-year
flood.

The orientation of the embankment was modified during the tests to minimize the possibility of
downstream channel erosion on the left or right bank. The orientation of boatchute 2 was changed
to align the direction of the flow to be parallel to the streambank. A wedge-shaped area was added
to the top of the embankment on the right to direct the flow away from the right bank of the river.
Both modifications had a positive effect on the flow downstream of the embankment. The tendency
for the flow to attack the banks was reduced. Bank erosion and channel maintenance should be
minimized by this design.

BIBLIOGRAPHY

Pugh, C. A., "Hydraulic Model Studies of Fuse Plug Embankments," U.S. Bureau of Reclamation.
REC-ERC-85-7, Denver, Colorado, December 1985.

Richard, Don, "Hydraulic Model Study of Riverside Park Dam, Grand Forks, North Dakota,"
prepared for the North Dakota State Water Commission, (date???).

Samad, Mohammed A., Ph. D., John M. Pflaum, William C. Taggart, and Richard E. McLaughlin,
"Modeling of the Undular Jump for White Water Bypass," Water Fomm '86, Proceedings of the
American Society of Civil Engineers, (date???).

Simmons, William P., Thomas H. Logan, Richard A. Simonds, and Richard J. Brown, "Model
Studies of Denver White Water Channel," Journal of the Hydraulics Division, American Society of
Civil Engineers, July 1987.

U.S. Army Corps of Engineers, "Summary Report, Model Tests of Little Falls Dam," Waterways
Experiment Station, May 1985.

Vanoni, Vito A., Sedimentation Engineering, American Society for Civil Engineers, ASCE Task
Commillee for Preparation of the Manual on Sedimentation Commillee of the Hydraulics Division,
No. 54, New York City, New York, 1975.

Wright Water Engineers, "Feasibility Study, Boat Bypass Structure at Union Avenue Dam,"
prepared for Colorado Water Conservation Board, September 1987.

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