FLOOD03543

• 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

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IImi

Wright Water Engineers, Inc.

DENVER OFFICE
2490 West 26th Ave., Suite 100 A
Denver. Colorado 80211
[phone]

October 30, 1989

GLENWOOD SPRINGS OFFICE
818 Colorado Avenue
P. O. Box 219
Glenwood Springs, Colorado 81602
[phone]
Denver Direct line: 893-1606

Mr. David W. Walker, Deputy Director
Colorado Water Conservation Board
721 State Centennial Building
1313 Sherman Street
Denver, CO 80203

Re: Preliminary Design Report for the Union Avenue Dam Boatchutes

Dear Mr. Walker:

BACKGROUND

Wright Water Engineers (WWE) is pleased to transmit the preliminary design for the
modifications to the Englewood Intake and the U.S. Army Corps of Engineers (USACE)
dam crest, embankment and the boatchutes located at Union Avenue on the South Platte
River. Included in this letter report are the items called for in Paragraph 3 of our contract
with the Colorado Water Conservation Board (CWCB), for the preliminary design of these
improvements on the South Platte River at Union Avenue.

The objective of the preliminary design is to provide a basis for the final design of the
project to reduce boater hazards in this reach of the South Platte River while maintaining
the operation of the existing USACE dam and city of Englewood water supply intake
structures. The project cannot eliminate hazards associated with the dam and intake.

The original report by WWE on this subject was submitted to the CWCB in September
1987 and was entitled "Engineering Feasibility Study, Boat Bypass Structure at Union
Avenue Dam, Englewood, Colorado". This bypass structure completely bypassed the
USACE dam on the left bank. The left bank bypass was selected on the basis of a risk
analysis. It was rejected during the review process.

This 1987 report was followed by meetings in August 1988 of the involved interests which
revised the adopted plan to an "over the dam" alternative. A copy of the August 22, 1988
memo on this meeting is included as Appendix A This revised "over the dam" alternative
was presented to the CWCB Board and approved by them at their September 1988 meeting.

Involved entities have included:

1. U.S. Army Corps of Engineers

2. Colorado Water Conservation Board