FLOOD10406

• County: Denver
• Community: Cherry Creek
• Stream Name: Cherry Creek
• Title: Agenda Item 11.f Sept. 27-29, 1999 Board Meeting - Report Regarding the Cherry Creek Dam Safety Study
• Date: 9/17/1999
• Prepared For: CWCB Board Members
• Prepared By: Larry Lang
• Floodplain - Doc Type: Project

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-Lj Colorado Water Conservation Board

, Department of Naturall Resources
1 31 3 Sherma n Street i
Denver, Colorado 80203 :
Phone: [phone]
FAX: [phone]

STATE OF COLORAI)O

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MEMORANDUM

Bill Owens
Covernor

TO: '

Colorado fWater Conservation Board Members

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Larry Laqg L.-:

Creg E, Walcher
Executive Director, ON R

Peter 1-1. Evans
Director, eweB

FROM:

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DATE: Septemb~rl7, 1999

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SUBJECT: Agenda I~em l1.f September 27-28, 1999 Board Meeting--
Report regarding the Cherry Creek Dam Safety Study

BACKGROUND

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On February 5 and 17, 1999, the Corps of Engineers, Omaha District, conducted public hearings
on the dam safety study for the Cherry Creek Dam and Reservoir. The public hearings attracted
much public concern anq raised many issues and questions regarding the study findings. The
Board has also received many questions. The Board responded to these questions and concerns
by conducting a basin to~r and discussions at its March 29-30, 1999 Board meeting. The Board
made a recommendation ito staff to seek legislative authorization and funding to perform a
technical review for the Probable Maximum Precipitation (PMP) and Probable Maximum Flood
(PMF) values. The lang~age in Section 16 of the CWCB Construction Bill 99-173 provides the
authorization and funding to seventy five thousand dollars ($75,000). On July 21,1999, the
Corps of Engineers, in cdoperation with Colorado Water Conservation Board, conducted a
formal technical discussion with a panel of meteorological and hydrological experts that were
jointly selected by the Cqrps and the Board. The panel heard testimony from the Corps and the
National Weather Servic~ (NWS) regarding the PMP models - HMR's study procedures and
parameters.

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Following the formal pre~entations by the Corps and NWS, a technical discussion was conducted
for 36 topics regarding th:e "Site Specific Probable Maximum Precipitation Study for the CherTY
Creek Drainage in Color~do" dated July 12, 1995. Most of the discussion topics reached an
answer of "No consensusiby the group". It should be noted that one desenting vote would result
in the no consensus answ~r. The findings of the July 21, 1999 review is presented in a
Summary Report entitledi"Cherry Creek Dam Safety Study, Summary Report, dated August 5,
1999". '

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