Animas-La PLata Project Environmental Impact Statement

TABLE OF CONTENTS (continued)
Chapter
Page No.
3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ....... 3 -1
3.1 INTRODUCTION ...................... ............................... 3 -1
3.1.1 Structural Components ............ ............................... 3 -1
3.1.2 Non - Structural Component ......... ............................... 3 -2
3.1.3 Non - Binding End Uses ............ ............................... 3 -2
3.1.4 Structure of Sections ................ '............................. 3 -3
3.2 WATER RESOURCESI HYDROLOGY ..... ............................... 3-4
3.2.1 Introduction ........................ ............................3 -4
3.2.2 Evaluation Methodology ........... ............................... 3-4
3.2.2.1 Methodology ............ ............................... 3-4
3.2.2.1.1 Configuration for Future Conditions Without the
Project ....................... ............. 3 -5
3.2.2.1.2 Configuration for the Refined Alternative 4 ....... 3 -5
3.2.2.1.3 Configuration for Refined Alternative 6 ......... 3 -12
3.2.2.2 Significance Criteria ..... ............................... 3 -14
3.2.3 Affected Environment ............ ............................... 3 -17
3.2.3.1 Refined Alternative 4 Structural Component ................. 3 -17
3.2.3.1.1 Animas River .............................. 3 -17
3.2.3.1.2 La Plata River ............................. 3 -18
3.2.3.1.3 Mancos River .............................. 3 -18
3.2.3.1.4 San Juan River ............................. 3 -18
3.2.3.1.5 Navajo Reservoir ........................... 3 -19
3.2.3.2 Refined Alternative 4 Non - Structural Component ............. 3 -19
3.2.3.2.1 Pine River . ............................... 3 -19
3.2.3.2.2 Florida River .............................. 3 -19
3.2.3.3 Refined Alternative 6 ......... I. ......................... 3 -19
3.2.3.3.1 Dolores River .............................. 3 -19
3.2.3.3.2 McElmo Creek ............................. 3 -20
3.2.4 Environmental Consequences and Mitigation ........................ 3 -20
3.2.4.1 Refined Alternative 4 .... ............................... 3 -20
3.2.4.1.1 Operation of Structural Components and Delivery
to Non - Binding Uses ........................ 3 -20
3.2.4.1.2 Water Conveyance Impacts for Non - Binding Uses . 3 -28
3.2.4.2 Refined Alternative 6 .... ............................... 3 -28
3.2.4.3 No Action Alternative . 3 -33
3.3 WATER QUALITY .................... ............................... 3 -34
3.3.1 Introduction ........................ ...........................3 -34
3.3.2 Evaluation Methodology .......... ............................... 3 -34
3.3.2.1 Methodology ........... ............................... 3 -34
3.3.2.1.1 Approach .. ............................... 3 -34
3.3.2.1.2 Standards by State .......................... 3 -35
3.3.2.1.3 Sites with Water Quality Measurements ......... 3 -37
3.3.2.1.4 Historic Streamflow Data .......... :......... 3 -37
3.3.2.1.5 Streamflow Data from the San Juan River
Hydrology Model ....................... . .. 3 -37
3.3.2.2 Significance Criteria ..... ............................... 3 -39
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