9376

• UCREFRP Catalog Number: 9376
• Author: CH2MHill.
• Title: Duchesne River Hydrology and Water Availability Study.
• USFW Year: 1997.
• USFW - Doc Type: \
• Copyright Material: NO

' CHAPTER 1
Introduction
1

Back oun
gr d
' The United States Fish and Wildlife Service (USFWS) has identified Duchesne River flows
as having potentially significant benefits to endangered fish. The lower 2-~i miles of the
Duchesne River have been designated as critical habitat for the razorback sucker. The
Management Committee of the Recovery Implementation Program for Endangered Fish
Species in the Upper Colorado River Basin (RIP) authorized funding for a comprehensive
review of the effects of existing and proposed projects on the flow regime in the designated
' critical habitat reach of the Duchesne River. The Central Utah Water Conservancy District
(CUWCD) acted as the contracting agent to complete the study with RIP funds. The
CUWCD contracted with CH2M HILL in March of 1996 to perform this study for an
interdisciplinary team made up of the staffs of the CUWCD, the USBR, the USFWS, the
Utah Department of Natural Resources (UDNR), the Ute Indian Tribe, and other Duchesne
- River water users and affected parties.

Study Description
The complete scope of services for the study is included in the Appendices. The scope of
services includes ten main tasks. Each of these tasks are briefly described below.
1. Information Gathering. This task included gathering data related to the study
effort on flow data of the Duchesne River, other flow data in the Basin, USBR
pre-development flow data, and operational data from the main water users on
the Duchesne River.
2. Workshops With Agencies. This task included holding workshops with
affected parties; on the study, its methods, the scope of work, study objectives,
' and the preliminary results of the study as it proceeded. A total of five
workshops were held.
3. Review of USBR Pre-Development Flows. This task focused on determining
the methodology, assumptions, and limitations of USBRpre-development flows.
4. Flow Analysis of Duchesne River Flow Records. This task analyzed flow
records to determine historical flows of the lower Duchesne River.
5. Flow Analysis of the Duchesne River Flows With Full CUP Bonneville Unit
Operation. This task looked at the effects of CUP Bonneville Unit operation on
the flows of the lower Duchesne River at Randlett.
6. Flow Analysis of the Duchesne River Flows With UBRP Proposed Operation.
' This task determined the effects of ultimate UBRP operation on the flows of the
lower Duchesne River at Randlett.

SLC~13470TREPTI.DOC 1 -1
1