1. Introduction
2. Background
3. Biological Assessment Content, Scope, and Public Process
   1. Request for Formal Consultation
   2. Content and Scope
      1. Action: A description of the action to be considered.
      2. Area: "A description of the specific area that may be affected by the action."
      3. Species and Critical Habitat Description: "A description of any listed species or critical habitat that may be affected by the action."
      4. Effects of the Action: "A description of the manner in which the action may affect any listed species or critical habitat and an analysis of any cumulative effects."
      5. Relevant Reports: "Relevant reports, including any environmental impact statement, environmental assessment, or biological assessment prepared...."
      6. Other Relevant Reports: "Any other relevant available information on the action, the affected listed species, or critical habitat."
   3. Public Process and Consultation Schedule

1. Introduction
2. The Secretary's Discretionary Management Activities
   1. Flood Control
   2. The Role of the Secretary as Watermaster of the Lower Colorado River Basin for Delivery and Storage of Water
   3. Declaration of Surplus
   4. Delivery to Mexico at the Northerly International Boundary (NIB)
   5. Water Delivery to Mexico at the Land Boundary near San Luis, Sonora
   6. Power Operations
   7. Channel Maintenance and Levee System
   8. Yuma Desalting Plant and 5-Mile Zone
   9. Endangered Species Conservation Activities
3. Lower Colorado River Operation and Maintenance Procedures
   1. Flood Control
   2. Annual Operating Plan
   3. Operation of the Colorado River Below Davis and Parker Dams
   4. Water Delivery Requirements to Mexico in Accordance with the Mexican Water Treaty of 1944
   5. Process for Daily Water Requirements and Hourly Release Schedule
      1. Parker Dam to Mexico
      2. Parker Dam to Davis Dam
      3. Davis Dam to Hoover Dam
      4. Seasonal Release Patterns
   6. River Maintenance
   7. Yuma Desalting Plant and 5-Mile Zone
4. Endangered Species Conservation Program
   1. Introduction
   2. Endangered Razorback Sucker and Bonytail Conservation
      1. Native Fish Work Group
      2. Willow Beach National Fish Hatchery
      3. HAVFISH Project
      4. Boulder City Golf Course Native Fish Rearing Project
      5. Hualapai Native Fish Rearing Facility
   3. Native Riparian Plant Restoration
      1. Native Riparian Plant Nurseries
      2. Demonstration Projects
      3. Enhancement Projects
      4. Research
   4. Three-Finger Lake Project
   5. Boulder City Wetland Project
   6. Lower Imperial Division Wetland Enhancement
   7. Las Vegas Wash Wetland Restoration
   8. Multi-Species Conservation Program Development
5. Summary of Secretary's Non-Discretionary and Discretionary Operation and Maintenance of the Lower Colorado River
   1. Introduction
   2. Non-discretionary
   3. Varying Degrees of Discretion
   4. Fully Discretionary

1. Historic and Present Biological Communities on the Lower Colorado River
   1. Introduction
   2. Riparian Communities
      1. Historic
      2. Present
   3. Marsh
      1. Historic
      2. Present
   4. Aquatic
      1. Historic
      2. Development Along the Lower Colorado River
      3. Effects of Development and Present Day Aquatic Baseline
2. Previous and Ongoing Section 7 Consultations
   1. Colorado River Mainstem
   2. Baseline Projects
      1. Central Arizona Project Havasu Diversion
      2. Southern Nevada Water System (Robert B. Griffith Water Project)
   3. Salton Sea and Endangered Desert Pupfish
3. Non-Federal (Contemporaneous and Cumulative) Actions

1. Introduction
2. Terrestrial
   1. Endangered
      1. Peregrine Falcon (Falco peregrinus)
      2. Southwestern Willow Flycatcher (Empidonax traillii extimus)
   2. Threatened
      1. Bald Eagle (Haliaeetus leucocephalus)
      2. Desert Tortoise (Gopherus agassizii) (Mojave & Sonoran populations)
   3. Proposed Threatened
      Flat-tailed horned lizard (Phrynosoma m'callii)
   4. Sensitive
      1. California Leaf-Nosed Bat (Macrotus californicus)
      2. Spotted Bat (Euderma maculatum)
      3. Greater Western Mastiff-Bat (Eumops perotis californicus)
      4. Small-Footed Myotis (Myotis ciliolabrum)
      5. Allen's (Mexican) Big-Eared Bat (Idionycteris phyllotis)
      6. Pale Townsend's Big-Eared Bat (Plecotus townsendii pallescens)
      7. Long-Legged Myotis (Myotis volans)
      8. Fringed Myotis (Myotis thysanodes)
      9. Yuma Myotis (Myotis yumanensis)
      10. Cave Myotis (Myotis velifer)
      11. Yuma Hispid Cotton Rat (Sigmodon hispidus eremicus)
      12. Loggerhead Shrike (Lanius ludovicianus)
      13. Large-billed Savannah Sparrow (Passerculus sandwichensis rostratus)
      14. Arizona Toad (Bufo microscaphus microscaphus)
      15. Desert tortoise (Sonoran population) (Gopherus agassizii)
      16. Rosy Boa (Lichanura trivirgata)
      17. Cowles's fringe-toed lizard (Uma notata rufopunctata)
      18. Chuckwalla (Sauromalus obesus)
      19. Grand Wash Springsnail or Grapevine Springsnail (Pyrgulopsis bacchus)
      20. White Desertsnail (Eremarionta immaculata)
      21. Cheeseweed owlfly (aka moth lacewing, mothlike netwing, ithonid lacewing) (Oliarces clara)
      22. MacNeill's sootywing (Hesperopsis gracielae)
      23. Dune sunflower, silver-leafed sunflower - (Helianthus niveus ssp. tephrodes)
      24. Sand food (aka sand sponge, sand root, or biatatk [Tohono O'odham word meaning "sand root," Jaeger 1940]) (Pholisma sonorae)
      25. Foxtail cactus (Coryphantha vivipara var. alversonii)
      26. Crissal Thrasher (Toxostoma crissale coloradense)
3. Marsh
   1. Endangered
      1. Brown Pelican (Pelecanus occidentalis)
      2. Yuma Clapper Rail (Rallus longirostris yumanensis)
   2. Sensitive
      1. California Black Rail (Laterallus jamaicensis coturniculus)
      2. Western Least Bittern (Ixobrychus exilis hesperis)
      3. White-faced Ibis (Plegadis chihi)
      4. Fulvous Whistling Duck (Dendrocygna bicolor)
4. Aquatic
   1. Endangered
      1. Colorado Squawfish (Ptychocheilus lucius)
      2. Razorback Sucker (Xyrauchen texanus)
      3. Bonytail (Gila elegans)
   2. Critical Habitat Description - Razorback Sucker and Bonytail
   3. Sensitive
      1. Flannel Mouth Sucker (Catostomus latipinnis)
      2. California floater (Anodonta californiensis)
5. Mexico Species
   1. Desert pupfish (Cyprinodon macularius)
   2. Vaquita (Phocoena sinus)
   3. Totoaba (Totoaba macdonaldi)
6. Summary of Effect Analyses

APPENDIX A - LOWER COLORADO RIVER MULTI-SPECIES CONSERVATION PROGRAM

APPENDIX B - CONSULTATION AGREEMENT

APPENDIX C - RIVER WORK AND MAINTENANCE

Introduction and Past History

Major Activities Along the Lower Colorado River

Mohave Valley Division
Topock Gorge Division
Havasu Division
Parker Division
Palo Verde Division
Cibola Division
Imperial Division
Laguna Division
Yuma Division
Limitrophe Division

APPENDIX D - MAJOR FACILITIES ON THE LOWER COLORADO RIVER

Laguna Dam
Hoover Dam
Imperial Dam
Parker Dam
Davis Dam
Headgate Rock Dam
Palo Verde Diversion Dam
Senator Wash Pumping/Generating Plant and Regulating Reservoir
Glen Canyon Dam
Morelos Dam
All-American Canal, Pilot Knob and Siphon Drop Powerplants
The Gila Gravity Main Canal

APPENDIX E - HISTORICAL AND PROJECTED RESERVOIR OPERATIONS ON THE LOWER COLORADO RIVER

Introduction
Historical Hoover Dam/Lake Mead Operations
Historical Davis Dam/Lake Mohave Operations
Historical Parker Dam/Lake Havasu Operations
Comparison of Projected vs Historical Operations for Lake Mead/Hoover Dam
Comparison of Projected vs Historical Operations for Lake Mohave/Davis Dam
Comparison of Projected vs Historical Operations for Lake Havasu/Parker Dam
Historical And Projected Water Use - Lees Ferry to Mexico

APPENDIX J - BIBLIOGRAPHY/LITERATURE CITED

Table 1. List of documents known collectively as "The Law of the River"

Table 2. List of Endangered, Threatened, Proposed Threatened, and Sensitive Species in the United States and Mexico

Table 3. Minimum and maximum flow rates for the delivery of water to Mexico at the NIB

Table 4. Chronology of Lower Colorado River Development

Table 5. 1986 acreage of lower Colorado River floodplain vegetation community types per river maintenance division

Table 6. 1994 acreages of lower Colorado River floodplain vegetation community types per river maintenance division

Table 7. Marsh types and criteria used in classification lower Colorado River

Table 8. Surface acreage of water along the Colorado River from Pierce Ferry to the U.S./Mexico International Boundary by river maintenance division

Table 9. Section 7 Consultations, Endangered Species Act, Lower Colorado River

Table 10. List of non-Federal activities that affect the resources of the lower Colorado River and its extended environs

Table 11. Amounts and uses of water diverted by principal water entitlement users in 1993

Table 12. Acreage comparison for cottonwood-willow and saltcedar communities/structures between 1976 and 1994

Table 13. Agency actions that have undergone section 7 consultation and levels of Incidental Take permitted for the Southwestern Willow Flycatcher range wide

Table 14. Collection records of the moth lacewing, Oliarces clara

Table 15. Collection records of MacNeill's sootywing, Pholisora graciliae

Table 16. Summary of Effect Analyses

Table C-1. Levee & bank line system for the lower Colorado River by river-miles and division

Table E1. Sum of all Colorado River use by Arizona, California, and Nevada; Lees Ferry to Mexico

Table E2. Sum of all Colorado River uses above Hoover Dam

Table E3. Sum of all Colorado River uses Hoover Dam to Davis Dam

Table E4. Sum of all Colorado River uses Davis Dam to Parker Dam

Table E5. Sum of Colorado River use by Arizona and California below Parker Dam

Table E6. Mexico use in satisfaction of Treaty

Table E7. Robert B. Griffith Water Project (SNWS) use

Table E8. Metropolitan Water District of Southern California use

Table E9. Central Arizona Project use

Table E10. Projected Colorado River use

Figure 1. Description area within the Colorado River Basin

Figure 2. Detail of the Colorado River description area showing river maintenance divisions

Figure 3. Location of critical habitat for bonytail and razorback sucker

Figure 4. Schematic of annual lower Colorado River releases and diversions in million acre-feet

Figure 5. Side-view schematic of lower Colorado River from Pierce Ferry to the SIB

Figure 6. Natural flow at Lees Ferry

Figure 7. Flow below Hoover Dam

Figure 8. Lake Mead end-of-month elevations - 1935 to 1996

Figure 9. Typical season flow of Colorado River below Davis Dam

Figure 10. Typical spring flows on Colorado River below Parker Dam

Figure 11. Typical summer flows on Colorado River below Parker Dam

Figure 12. Typical fall flows on Colorado River below Parker Dam

Figure 13. Typical winter flows on Colorado River below Parker Dam

Figure 14. Copy of Release Schedule (a) and Actual Release (b) from Parker Dam

Figure 15. Lake Havasu operational constraints

Figure 16. Typical dynamic power generation measured at the Hoover Dam 230-kV bus

Figure 17. Lake Mohave pre-1998 (curve A) and post-1998 (curve B) operational constraints

Figure 18. Hoover actual releases

Figure 19. Davis actual releases

Figure 20. Parker actual releases for October 28, 1994

Figure 21. Three-finger Lake Project

Figure 22. Boulder City Wetland

Figure 23. Lower Imperial Division Wetland Enhancement

Figure 24. 1879-1977 Comparison of vegetation communities along same stretch of lower Colorado River near Blythe, California

Figure 25. Historic lower Colorado River floodplain and associated vegetation communities

Figure 26. Reconstruction of native plant community placement and species composition

Figure 27. Examples of vertical configurations for the vegetation structural types

Figure 28. 1995 Colorado River delta at Lake Mead vegetation classification

Figure 29. Areas of known occurrence of desert tortoises in Arizona

Figure C-1. Quarry Sites. Map No. 423-LC-222

Figure D1. List of owner/operators for major facilities along the lower Colorado River

Figure E-1. Map and operational diagram of the lower Colorado River [Map Number 423-300-59 (Revised April 1993)]

Figure E1. Hoover daily release

Figure E2. Hoover daily flow duration

Figure E3. Hoover daily mean release range

Figure E4. Hoover actual releases

Figure E5. Lake Mead daily elevation

Figure E6. Lake Mead daily elevation range

Figure E7. Lake Mead monthly elevation change

Figure E8. Davis daily release

Figure E9. Davis daily flow duration

Figure E10. Davis daily mean release range

Figure E11. Davis actual releases

Figure E12. Lake Mohave daily elevation

Figure E13. Lake Mohave daily elevation range

Figure E14. Lake Mohave monthly elevation change

Figure E15. Parker daily release

Figure E16. Parker daily flow duration

Figure E17. Parker daily mean release range

Figure E18. Parker actual releases

Figure E19. Lake Havasu daily elevation

Figure E20. Lake Havasu daily elevation range

Figure E21. Lake Havasu monthly elevation change

Figure E22. Hoover Dam release

Figure E23. Hoover monthly release distribution

Figure E24. Flow depth below Hoover

Figure E25. Hoover flow depth distribution

Figure E26. Lake Mead elevation

Figure E27. Lake Mead elevation distribution

Figure E28. Davis Dam release

Figure E29. Davis monthly release distribution

Figure E30. Flow depth below Davis Dam

Figure E31. Davis flow depth distribution

Figure E32. Lake Mohave operational constraints

Figure E33. Parker Dam release

Figure E34. Parker monthly release distribution

Figure E35. Flow depth below Parker Dam

Figure E36. Parker flow depth distribution

Figure E37. Lake Havasu operational constraints