BOARD00775

• Board Meeting Date: 11/19/2001
• Description: Flood Section - Non-Reimbursable Investments - Chatfield Reservoir Reallocation Study
• Board Meetings - Doc Type: Memo

~;i:

,
.

e

e

e

- ft' '..

STATE OF COLORADO

Colorado Water Conservation Board
Department of Natural Resources
1313 Sherman Street, Room 721
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
www.cwcb.state.ca.us

~

Bill Owens
Governor

MEMORANDUM

Greg E. Walcher
Executive Director

TO:

Colorado Water Conservation Board Members
1-/"
Larry Lakg!Chief, Flood Protection Section

Dan McAnliffe
Deputy Director

Rod Knharich
CWCB Director

FROM:

DATE:

October 29, 2001

RE:

Agenda Item 24.g, November 19-20, 2001 CWCB Meeting
Water Supply Planning and Finance, Non-Reimbursable Investments
Chatfield Reservoir Reallocation Study

Introduction
The CWCB in cooperation with the Corps of Engineers is in the second year of the four year Chatfield
Reservoir Reallocation Study. The objective of the study is to determine the feasibility for the
development of water supply storage in the existing Chatfield Reservoir. During the negotiations of
the study with the Corps and our Study Contractors, we anticipated that additional study tasks and costs
would be required for the accomplislnnent of the study objective.

In the performance of Year Two study tasks, certain additional tasks must be performed and an
opportunity exists to prepare new 100- year floodplain information for the two hundred twelve (212)
mile reach of the South Platte River downstream of Denver to the state line.

Staff presents four additional study tasks:
· Environment Investhmtion - The Preble's Meadow Jumping Mouse is present within the study
area. Additional study is required to better understand and define the Mouse's habitat. The
Mouse's life cycle can have a direct relationship to reservoir operations.
· Seismic ( earth~uake) Investilmtions - The existing Chatfield Dam embankment design did not
analyze the earthquake risk. Today, it is a federal dam design requirement that the earthquake risk
must be addressed,
· Recreational Plannine and Desien - The Colorado Division of Parks has stated a number of
relocation concerns that the study contractor must investigation and prepares project
recommendations. To address these concerns in a timely manner, the study contractor needs to
hire a sub-contractor that can intelligently evaluate these concerns and provide project
recommendations.
. 100- Year Floodulain Information - An opportunity for the preparation of detailed floodplain
maps exists as a by-product of the Hydrology and Hydraulic Determinations that must performed

Flood Protection. Water Project Planning and Financing. Stream and Lake Protection
Water Supply Protection. Conservation Planning

t