C153642 Feasibility Study

• Contract/PO #: C153642
• Contractor Name: Colorado River Water Conservation District
• Contract Type: Loan
• Water District: 0
• County: Garfield
• Loan Projects - Doc Type: Feasibility Study

I
I
I
I
I

General Approach................................................................................... 4-26
Single-Discipline Evaluations..................................................,.................. 4-27
Multi-Disciplinary Evaluation.................................................................... 4-27
Site Selection Recommendations ..... ............. ......................... ...................... 4-29

CHAPTER 5 . Development of Basin Model

Modeling Objectives and Approach ...................................................................... 5-1
Review of Previous Basin Modeling .............................................................:....... 5-1
The HYDROSS Model...................,.......................................................... 5-1
Hydrology and Demands Represented in the HYDROSS Model......,.................... 5-2
Review of HYDROSS Modeling Assumptions................................................. 5-2
Comparison of HYDROSS and Feasibility Study Depletion Assumptions ............... 5-3
Development of Basin Model.............................................................................. 54
Introduction to Network Modeling ............................................................... 5-5
Model Configuration ....... ........... ......... ............... ......... .............. ............... 5-5
Representation of Hydrology in the Basin Model............................................. 5-10
Representation of Demands and Reservoirs.. ..... .................. ..... ................. ..... 5-15

Reservoir Operations..,............................................................................ 5-24
Model Validation... ....,.... ........,..... ....... .......... .... .... .............. ...... .............5-26

CHAPTER 6 - Evaluation of Alternatives

Overview ...................................................................................................... 6-1
Evaluation Criteria......... ......... .... ....... ...:....... ..'............ ..... ..,.................,.. 6-1
Use of the Basin Model........ ........... ...... .......... ........... .... ......... '" ...............6-1
Definition of Alternatives .......................................................................... 6-2
Scenario I - No Action (Baseline)......................................................................... 6-3
Key Assumptions of Scenario ..................................................................... 6-3
Results of Scenario I ............... ........................ .................. ........... ............ 6-6
Scenario II - Conversion of Juniper Rights Only...................................................... 6-8
Key Assumptions of Scenario ..................................................................... 6-8
Results of Scenario II ...... ............................. ............ ....... ........................6-11
Scenario 1II - Enlargement ofElkhead Reservoir.....................................................6-14
Key Assumptions of Scenario .' ............ ............ ....... .... ............ ........... .... ....6-14
Results of Scenario III ............ ....................... .................................. ........ 6-16
Scenario IV - Enlargement of Elkhead and Stagecoach

Reservoirs.................................................................................... 6-20
Key Assumptions of the Scenario........ .............. ........ .......................... ........ 6-20
Results of Scenario IV .............................................................................6-20
Scenario V - Elkhead Enlargement with

Williams Fork Project. ........... ..... ...... ......... ............. ......... .......... ...... 6-22
Key Assumptions of Scenario ...... .... ............... ..... ....................,... ..............6-22
Results of Scenario V .. .............. ..................... .......... ....................... ........ 6-25
Environmental Considerations .......... ........ ........................ ............... ........... ........6-29

Sport Fisheries..................................,.......................,............................ 6-29
Flow Conditions in Occupied Habitat........................................................... 6-35
Wetlands and Wildlife Impacts... .......................... ............. ....... .................. 6-37
Project development Cost........... ...... .......................... .............. ................. ....... 6-38

General......................,................,.........................................,.............. 6-38

iii