9477

• UCREFRP Catalog Number: 9477
• Author: McAda, C. W.
• Title: Flow Recommendations to Benefit Endangere Fishes in the Colorado and Gunnison Rivers.
• USFW Year: 2003.
• USFW - Doc Type: Project number 54,
• Copyright Material: NO

Page
LIST OF TABLES ....: .... ................... .: ... .................. iv
LIST OF FIGURES ...... ....................... ..... .............. ix
NOTATION ................. ...... ...................... .......... xv
ACKNOWLEDGMENTS ...... .... ...... .. .............. xvii
EXECUTIVE SUMMARY ............................ ....... xviii
1.0 INTRODUCTION ....... ... .... .:........... 1-1
1.1 Background ..... ................ ..... ...... . 1-1
1.2 Overview of Aspinall Unit Investigations ..... ..... .............. 1-5
1.2.1 Study Area ......................: ................... 1-6
1.2.2 Study Objectives and Approach ....... ........ ....... ... 1-6
1.2.3 Aspinall Unit Operations During the Study Period ....... 1-9
1.2.4 Development of Integrated Flow Recommendations ................ 1-9
2.0 HYDROLOGY AND GEOMORPHOLOGY OF THE COLORADO AND
GUNNISON RIVERS .....: .... .. .. .... 2-1
2.1 Hydrology ................ .......... .............. 2-1
2.1.1 Overview .... , ......... ..... 2-1
r ..... 2,1.2 Water Development ... ... -
2.1.3 Historical Operation of the Aspinall Unit .. .............. 2-14
2.1.4 Aspinall Unit Operation During the Study Period ... ............ 2-16
2.2 Geomorphology . ..... ...... .......... ... ....... 2-23.
2.2.1 Longitudinal Variation .................. ......... ..... . 2-23
2.2.2 Influence of Water Development on Sediment Transport
and Channel Maintenance ...... ....................... 2-29
2.2.3 Relationship of Fine Sediment to Periphyton and
Invertebrate Biomass ...... ..................:.............. 2-38
2.2.4 Influence of Water Development on Floodplain Inundation ......... 2-45
2.2.5 Influence of Water Development on River Temperature ............ 2-49
3.0 FISHES OF THE COLORADO AND GUNNISON RIVERS ................. 3-1
3.1 Fish Community ............................. .................... 3-1
3.1.1 Native Species ............................ .. ........... 3-1
3.1.2 Nonnative Species .................................... ... 3-2
3.1.3 Influence of River Flow on Non-Endangered Fishes in the
Colorado and Gunnison Rivers ................................ 3-8
Final Report i July 2003