PROJ00382

• Contract/PO #: C153685
• Contractor Name: Monument, Town of
• Contract Type: Loan
• Water District: 10
• County: El Paso
• Bill Number: SB 94-029
• Loan Projects - Doc Type: Feasibility Study

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Table of Contents

C ertificatio n ........................................................................................................................

Acknowledgments ......... ... .................. ..... ....... ....... .... .... .... ..... ................................. .......... ...

Executive Summary.............................................................................................................

Table of Contents.................................................................................................................

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111
V

Chapter I - In trod uctio n ........... ................................ ........................ ........................ ..................................1

Chapter II - Description of Sponsoring Entity..........................................................................................5

Chapter III - Background Information .....................................................................................................6

A. Previous Studies......................................................... ................................................ .........6
B. Project History.............................................. ..... ..... ................................ ............... ..............6
C. Study Area and Existing Facilities Description ................................................................... 7

D. Water Demands ................................................................................................................. 12
E. Hydrology and Water Rights .............................................................................................13
E.1 Flood Hydrology """"'''''''''''''''''''''''''''''''''''''''''''''..........................,.........................13

E.2 Water Rights ............................................................................................................... 14
F. Field Investigations.... ........................... ............... ......................................... .............. ....... 15

Chapter IV - Formulation of Alternatives...............................................................................................24
A. Spillway Alternatives.... ......................................... ...... .............................................. ....... .24
Spillway Alternative SI - Riprap / Concrete Drop Chute .................................................24
Spillway Alternative S2 - Concrete Chute ........................................................................25
B. Embankment Alternatives...... ..........., ..... ..................... ........................ ....'''''''''' ............. ...25
Embankment Alternative E1 - Chirru1ey/Blanket Drain System .......................................26
Embankment Alternative E2 - Blanket Drain System.......................................................27
C. Outlet Wodes Alternatives ""'''''''''''''''''''''''''''''''''''''''''''''''''''................"........................27
Outlet Works Alternative 01 - Upstream Gate Design .....................................................28
Outlet Works Alternative 02 - Gate Chamber Design......................................................28
Outlet Works Alternative 03 - Gate .rower Design ..........................................................28
D. Reservoir Dredging Alternative........................ .......................................................... ..... ..29
E. Breach and Restore Alternative .........................................................................................30

Chapter V - Evaluation of Alternatives...................................................................................................46

A. Impacts....... .................... ................................................................................................. ..46
A.1 Man-Made Environmental Impacts .............................................................................46
A.2 Natural Environmental Impacts................... ..... ........................................ ................ ...46
A.3 Social Structure Impacts...................................... ........................................................48
B. Institutional Considerations..................................... ..........................................................49
C. Comparative Evaluation..... ...............'"'' .............. ........................ ................... ...... ............49
C.I Spillway Alternatives ..................................................................................................50
C.2 Embankment alternatives ............''''''''''''''''''''''''''''''''",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ..53
C.3 Outlet Works Alternative ............................................................................................57
C.4 Reservoir Dredging .......... ..................... ........... ...........................................................59

Chapter VI - Selection of Alternative and Financial Plan......................................................................64

Monument Lake Dam Feasibility Study

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