WSP06389

• File Number: 8220.102.01.I
• Description: Aspinall ‎(AKA Curecanti)‎
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 1/1/1994
• Title: Scopes of Work - Endangered Fish Program as Related to Aspinall
• Water Supply Pro - Doc Type: Report/Study

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No. : ASPINAL E
(for MC use)

RBCOVBRY DlPI.BIIBNTATIOK PROGRAJI
POR THB BRDAROBRBD PISH SPBCIBS
III THI UPPBR COLORADO RIVBR BASIK

PY-1994
SCOPB-OP-WORJt
RBSBARCH PROPOSAL

Lead Agency:
Submitted by:
Address:

Utah Wildlife Resources
Leo Lentsch
1596 West North Temple,
Salt Lake City, UT 84116
[phone]
April 28, 1993

Cateaorv (check onel :
_%_ ODgoing project
Requested new start
Unsolicited project
Outside funding

Phone:
Date:

I. Title of Proposal:

Aspinal Studies: Flow Effects on Humpback Chub Populations in Westwater
Canyon (ongoing but expanded)

II. Relationship to Recovery Program/Ranking Factors:

This study will be conducted cooperatively by Utah Division of Wildlife
Resources (UDWR) , Colorado Division of Wildlife (CDOW) , U.S. Fish and
Wildlife Service (FWS) , BIO/WEST, Inc., and Larval Fish Laboratory (LFL)
as part of the studies to assess the opportunities to re-regulate the
Aspinal Unit to benefit endangered fishes in the Gunnison and Colorado
rivers. The study focuses on the Westwater Canyon population of humpback
chubs in the Colorado River 40 to 50 miles below the Gunnison River
confluence. It is designed to specifically address the effect of high
spring flows on successful reproduction and recruitment of humpback chub,
as well as the effect of seasonal flow events on the formation of critical
habitat and the invasion/proliferation of non-native species. The study
will also assess the effects of flows on the invasion of roundtail chubs
into Westwater Canyon and the potential impact of hybridization.

III. Study Goals, Objectives, End Product:

The goal of this investigation is to develop flow recommendations for the
Colorado River to protect spawning and nursery habitat of humpback chub in
Westwater Canyon. Currently, there are no flow recommendations for
humpback chub in the upper basin. Maintenance of the populations in these
areas is vital since these areas support the largest numbers of the
species in the upper basin. The objectives of the study are to: (1)
Determine spawning and nursery requirements, (2) Describe the relationship
between geomorphological processes of sediment transport and nursery
habitat formation and maintenance in Westwater Canyon. (3) Identify and
describe reproductive isolating mechanisms, and (4) Assess recruitment.
The end product will be flow recommendations for spawning and nursery
habitat as well as recruitment of humpback chub in Westwater Canyon.

IV. Study area:

The study area is a 13-km reach of the upper Colorado River (RM 116 -124)
within Westwater Canyon, Utah.

V. Study Methods/Approach: See attachment

This study is designed to assess the effect of high spring flows on