I. OVERVIEW

This biological assessment (BA) 1) describes the U.S. Bureau of Reclamation's (Reclamation) current and projected routine lower Colorado River operations and maintenance, 2) describes the environmental baseline, 3) discusses critical habitat and the biology and distribution of species along the lower Colorado River that have protected status, or may be subject to such status under the Endangered Species Act of 1973, as amended (ESA), and 4) determines the potential effect of such operations and maintenance on such species. The ESA section 7 consultation resulting from this BA focuses on those actions in which there is discretionary Federal (Reclamation) involvement or control.

The geographic area included in this BA is within the lower Colorado River basin (Figure 1) and is focused on the mainstream lower Colorado River and its 100-year flood plain, from the upper end of Lake Mead at Pierce Ferry to the Southerly International Boundary with Mexico (SIB) (Figure 2). The BA addresses Reclamation’s discretionary operations of lower Colorado River dam facilities, maintenance of river control features, and other activities such as endangered species conservation.

In the United States, the Colorado River drains about 250,000 square miles from portions of seven States - Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona, and California. Over 170,000 square miles of the watershed are above Hoover Dam. The headwaters of the Colorado River are located in central Colorado, about 1,440 river-miles upstream from its mouth and 1,000 river-miles upstream from Hoover Dam.

The upper Colorado River basin ranges from 3,000 to over 14,000 feet in elevation and supplies most of the water discharge which occurs in the entire basin. Most water discharge occurs during the months of April through July when the winter snowpack melts. The area of the lower Colorado River basin is generally arid, with very little tributary runoff reaching the mainstream of the Colorado River, except during occasional storms. Lee Ferry, 15.5 miles downstream of Glen Canyon Dam, is cited in the Colorado River Compact as the boundary between the upper basin and the lower basin of the Colorado River.

Management of Colorado River water resources is a complex undertaking involving physical, biological, socioeconomic, and legal considerations. Management of the river is governed by an international treaty with Mexico and several minutes of the International Boundary and Water Commission (IBWC), two major interstate compacts, a Decree of the U.S. Supreme Court, various statutes, and contracts between the United States and water and power customers. These collectively are known as the "Law of the River" (Table 1).

The Federal role in managing the lower Colorado River differs in many respects, sometimes significantly, from its role in the upper basin. In the lower basin of the Colorado River, Reclamation serves as custodian for the Secretary of the Interior (Secretary) in his role as the Watermaster. As Watermaster, the Secretary’s three operational priorities are: 1) river regulation, improvement of navigation, and flood control, 2) irrigation and domestic uses, including the satisfaction of present perfected water rights, and 3) power.

In discussions with the U.S. Fish and Wildlife Service (FWS) and non-Federal parties that have an interest in the use and management of resources associated with the lower Colorado River, Reclamation has agreed to develop this BA as an initial description of routine, ongoing river operations and ESA-protected resources. As an assessment of the potential effects of discretionary operations on ESA-protected resources, this document serves two purposes: 1) initial documentation for the ongoing ESA section 7 consultation between Reclamation and FWS, and 2) initial reference for development and implementation of a multi-species conservation program by river stakeholders. The first purpose addresses Reclamation’s current discretionary operation and maintenance of the river, while the second purpose addresses non-Federal actions via an ESA section 10 permit application and future Federal actions via section 7 of ESA. The latter permits both non-Federal and Federal parties to participate together in the Lower Colorado River Multi-Species Conservation Program (MSCP). Sections 7 (Federal) and 10 (non-Federal) are separate processes under the ESA, yet they are anticipated to work concurrently toward natural resource conservation in the lower Colorado River.

Since there is significant non-Federal interest in developing and implementing an MSCP that could significantly affect the survival and recovery of ESA-protected species, the Department of the Interior (DOI), which includes Reclamation and FWS, agreed to work with public and private interests in the lower basin States (Arizona, California, Nevada) to develop and implement such a multi-species conservation plan. This agreement was formalized via a memorandum of agreement with an effective start date of August 2, 1995, and, in July 1996, is being clarified through a memorandum of clarification. The agreement among Federal and non-Federal agencies to form a partnership with other interested parties for the purpose of developing the MSCP was announced via a DOI news release dated September 15, 1995. On June 26, 1996, DOI and the MSCP steering committee signed an agreement to equally cost share the development of the MSCP and implementation of interim conservation measures. A summary of the MSCP and copies of the referenced news release and Federal/non-Federal cost-sharing agreement are provided in Appendix A.

The MSCP planning effort was originally scheduled for completion on or about 1998. During the 3-year period (August 1995 -August 1998) for developing the MSCP, it is proposed that participating agencies, both Federal and non-Federal, will sponsor, fund, and implement interim conservation measures, at a minimum, designed to aid in the survival and recovery of the endangered razorback sucker and bonytail. Consequently, the immediate needs of some of the ESA-protected species will be addressed and, thus, will not have to wait until the MSCP is formulated and implemented. Actually, Reclamation is presently participating in significant efforts to assure the survival of the endangered razorback sucker and bonytail. These and other voluntary conservation measures under Section7(a)(1) of the ESA are discussed in Section II of this document.

This BA serves as a written request, under the provisions of Title 50 Code of Federal Regulations (CFR) Part 402.14, to initiate formal consultation with FWS on Reclamation’s discretionary routine operations and maintenance on the lower Colorado River from the full pool elevation of Lake Mead to the SIB. Under 50 CFR 402.12(j), a Federal agency may initiate formal consultation concurrently with the submission of a biological assessment to FWS. Reclamation is requesting formal consultation based on its "may affect," "may affect, but not likely to adversely affect," and "may adversely modify critical habitat" (50 CFR 402.14 and FWS 1994 Draft Endangered Species Consultation Handbook) determinations as discussed in Section IV of this document. Additionally, a conference with FWS is requested on the proposed listing of the flat-tailed horned lizard as threatened.

"The contents of a biological assessment are at the discretion of the Federal agency and will depend on the nature of the Federal action" [50 CFR 402.12 (f)]. However, under 50 CFR 402.14(c), the request for formal consultation shall include information in six (a-f) basic areas:

"Action means all activities or programs of any kind authorized, funded, or carried out, in whole or in part, by Federal agencies in the United States or upon the high seas. Examples include, but are not limited to: (a) actions intended to conserve listed species or their habitat;...(d) actions directly or indirectly causing modifications to the land, water, or air." (50 CFR 402.02).

Under 50 CFR 402.03 Applicability, it is stated that "Section 7 and the requirements of this part apply to all actions in which there is discretionary Federal involvement or control."

Thus the Federal action addressed by this BA and the formal section 7 consultation under provisions of the ESA are those discretionary functions within the authority of the Secretary. Based on the perponderence of the public comments on the March 1996 draft of this document, it is necessary to clearly distinguish between the Secretary’s non-discretionary and discretionary authorities. This distinction is discussed in detail in "Section II. Description of Action" portion of this document; however, a short introductory discussion is provided below.

The Secretary’s discretionary management of the lower Colorado River, by Reclamation, is very limited through provisions contained in a number of compacts, Supreme Court decrees, international treaties, various statutes, and contracts between the United States and water entitlement holders and power customers. Again, these and other requirements are collectively known as the "Law of the River" (Table 1). In meeting these decree, treaty, and other obligations, the Secretary does have some meaningful, but limited, discretion in how water andpower are managed, depending on the situation, on a short-term basis in lakes and river reaches.

During a "normal" water year and assuming no problems with non-beneficial use, waste, or system failures, the Secretary is obligated to deliver at least 9 million acre-feet (maf) of water to the three lower basin States of Arizona, California, and Nevada (total 7.5 maf) and to Mexico (1.5 maf). Pursuant to the Boulder Canyon Project Act (43 U.S.C. § 617 et seq.), the Secretary has executed contracts with the States of Nevada and Arizona for 300,000 acre-feet and 2.8 maf, respectively. Within each State, including California, there are numerous entities that have Federal reserved water rights, pre-1929 present perfected water rights recognized in the Supreme Court’s decrees, or permanent service contracts with the Secretary executed under section 5 of the Boulder Canyon Project Act. The United States also has treaty obligations to deliver water to Mexico.

Due to these mandates and obligations, the Secretary must deliver water entitlements when the water is ordered. This applies to all water entitlement holders, whether an Indian tribe, irrigation district, wildlife refuge, municipality, national recreation area, or Mexico. In doing so, the Secretary exercises discretion, although it is usually narrow, in how water is stored in system reservoirs and released through Federal facilities. Deliveries are determined by specific water delivery orders and are patterned under contractual obligations for power generation at Hoover, Davis, and Parker Dam’s hydropower generation facilities.

Additionally, the Secretary exercises limited discretion in managing flood events but has considerable discretion over river maintenance and Section 7(a)(1) [ESA] endangered species conservation measures.

"Action area means all areas to be affected directly or indirectly by the Federal action and not merely the immediate area involved in the action." [50 CFR 402.02]. It should be noted that the CFR definitions of "action" and "action area" differ, with the latter addressing geographical scope.

The geographical area of the discretionary actions under this section 7 consultation is the lower Colorado River from Lake Mead to the SIB, with the lateral boundary defined by the designated critical habitat (reservoirs to full pool elevation or the 100-year flood plain) for the endangered razorback sucker and bonytail (Figure 3). Non-Federal actions outside the geographical area, such as the diversion and use of reserved and present perfected water rights, are discussed under "Section III. Environmental Baseline."

In response to Reclamation's request for a species list, FWS, via fax transmission dated February 24, 1995, provided a list of potentially occurring species in Reclamation's operational area: 7 endangered species, 1 proposed endangered species, and 27 candidate species. Since the receipt of this list, the southwestern willow flycatcher was listed as endangered on March 29, 1995 (FR, Vol. 60, No. 38, February 27, 1995), and the bald eagle was down listed from endangered to threatened (FR, Vol. 60, No. 133, July 12, 1995). Also, Reclamation was advised on June 13, 1995, that the California black rail was a candidate species (Ted Cordery, pers. comm.). At an August 17, 1995, meeting of the species conservation plan work group (now MSCP), which included representatives of FWS, Reclamation discussed 1) that its species list had expanded to include the threatened Mohave population of the desert tortoise, four additional candidate species, and one species of concern to California, as well as, the designated critical habitat for the razorback sucker and bonytail, and 2) that it needed additional time to complete its baseline description of operations, maintenance, resources, and to conduct the effect analysis.

In responding to Reclamation’s memorandums dated December 26, 1995, and February 15, 1996, FWS memorandum dated March 19, 1996, concluded that "The Service does not have any additions to the list of threatened or endangered species contained in the document [Description of Operations...December 1995] for the United States portion of the Colorado River." However, in its memorandum FWS identified three Mexico species (desert pupfish, Vaquita or Gulf of California [Gulf] harbor porpoise, and totoaba) that "...should be included in the list of species for the consultation." Additionally, the FWS memorandum notified Reclamation that none of the sensitive species (32 former category 1 or 2 species) are among the FWS February 28, 1996, Notice of Review for species regarded as candidates for possible listing as endangered and threatened wildlife and plants under the ESA. As part of the public review process, Reclamation has also been requested to address the flat-tailed horned lizard, a species that has been proposed for listing as threatened. Consequently, this document addresses the potential effects of the "action" on 7 endangered species, 2 threatened species, 1 proposed threatened species, and 32 sensitive species in the United States. Three endangered species in Mexico are also discussed; one of which, the endangered desert pupfish, is also discussed under cumulative effects in the United States. These species are listed in Table 2 and are discussed in Section IV of this document.

Due to its range being outside the potential influence of the actions being addressed in this BA, the Hualapai southern pocket gopher has not been included in this final document. Also, during the public review of the draft BA, Reclamation received suggestions for the inclusion of additional species. With the limited time to complete this document and the lack of official ESA protection for these additional species, Reclamation was unable to include such species as suggested.

By letter dated April 10, 1996, Reclamation provided the National Marine Fisheries Service (NMFS) a copy of the March 1996 draft of this BA. In its June 28, 1996, letter, NMFS indicated that the totoaba and vaquita were under its jurisdiction as endangered under ESA. They determined that the vaquita and four species of listed sea turtles are not likely to be adversely affected by Reclamation’s lower Colorado River operations. In terms of the totoaba, NMFS indicated that Reclamation’s operations may potentially affect this species but requested additional information regarding treaty obligations and the Secretary’s discretion concerning the delivery of Mexican Treaty water. This information is provided in Sections II and IV (totoaba discussion) of this document.

The temporal scope for this section 7 consultation on Colorado River operations and maintenance is for a period of up to 5 years, or until the long-term MSCP is developed, whichever comes first. Due to the scope and complexity of issues involved on such a large river system, it is felt that the time frame of "up to 5 years" is necessary to formulate and implement a comprehensive, efficacious MSCP. It is expected that the MSCP will be developed and implemented well within this time frame and that interim conservation measures and/or any potential reasonable and prudent alternatives and measures proposed by FWS, as a result of this consultation, will address the needs of listed species and designated critical habitat during the development of the MSCP. Under the "reinitiation of formal consultation" provisions of 50 CFR 402.16, Reclamation will re-consult prior to the end of the 5-year period on its discretionary involvement or control over the action under consultation, or its implementation of its portion of the MSCP.

Critical habitat, as defined in section 3(5)(A) of the ESA, means "(i) the specific areas within the geographical area occupied by the species at the time it is listed..., on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protection; and (ii) specific areas outside the geographical area occupied by a species at the time it is listed..., upon a determination by the Secretary that such areas are essential for the conservation of the species." "Conservation," as defined by section 3(3), ESA, means "...the use of all methods and procedures which are necessary to bring any endangered species or threatened species to the point at which the measures provided pursuant to this Act are no longer necessary."

On April 20, 1994, much of the mainstream Colorado River from Lake Mead to Imperial Dam was designated as critical habitat for either or both the razorback sucker and bonytail (FR, Vol. 59, No. 54, March 21, 1994) (Figure 3). Of the original critical habitat proposal, only the "Davis Dam to the upstream end of Topock Marsh on the mainstream Colorado River" was determined "separable" and not designated as critical habitat.

The primary constituent elements used to define critical habitat for the razorback sucker and bonytail are water, physical habitat, and biological environment (FR, Vol. 58, No. 18, January 29, 1993). The lateral boundary of the designated critical habitat includes Lakes Mead, Mohave, and Havasu "...to their full pool elevations," and those portions of the 100-year flood plain that contain the constituent elements. Five additional selection criteria,

primarily habitat requirements for reproduction and recruitment and special management or protection needs, were used to designate critical habitat for the razorback sucker (FR, Vol. 59, No. 54, March 21, 1994).

Again, 50 CFR 402.02 provides definitions of potential effects of the action. These are:

"Effects of the action refers to the direct and indirect effects of an action on the species or critical habitat, together with the effects of other activities that are interrelated or interdependent with that action, that will be added to the baseline." Direct and indirect effects are discussed in Section IV for each species and critical habitat. Due to the various laws, decrees, and other directives associated with the "Law of the River," Reclamation considers the diversion and distribution of entitlement waters, subject to beneficial use and waste determinations, as not being under the meaningful discretion of the Secretary and, therefore, such non-Federal actions are not considered as interrelated or interdependent actions. However, they are considered as being contemporaneous and cumulative to the action under consultation and are addressed as such in "Section III. Environmental Baseline." Also, past and on going ESA compliance for authorized Reclamation projects (e.g., Central Arizona Project (CAP), Robert B. Griffith Water Project, and Front Work and Levee System Project) are summarized as part of the environmental baseline.

"The environmental baseline includes the past and present impacts of all Federal, State, or private actions and other human activities in the action area, the anticipated impacts of all proposed Federal projects in the action area that have already undergone formal or early section 7 consultation, and the impact of State or private actions which are contemporaneous with the consultation in process." The environmental baseline is a complex and difficult issue not only to identify, but to quantify historically. Many reviewers of the March 1996 draft of this document recommended that the description of the environmental baseline be improved. In responding to specific and general comments, Section II of this document has been revised to provide a chronology of major events on the lower Colorado River, additional description on temporal changes in flora and fauna, an expanded review of past and other ongoing consultations, and a discussion of contemporaneous (e.g., diversion and distribution of entitlement waters) and cumulative activities (future, reasonably certain to occur non-Federal actions). Although Section III addresses much of the baseline, a full picture of the environmental base line will require the inclusion of water management (e.g., historical and present hydrography) of Section II and current species range and status in section IV. Effects due to the Secretary’s non-discretionary actions are considered as part of the baseline.

"Indirect effects are those that are caused by the proposed action and are later in time, but still are reasonably certain to occur."

"Cumulative effects are those effects of future State or private activities, not involving Federal activities, that are reasonably certain to occur within the action area of the Federal action subject to consultation." As part of the public review of the March 1996 draft of this document, reviewers were requested to provide information regarding future and reasonably certain to occur non-Federal activities for inclusion in the final of this BA. Notification of specific actions was not received as part of the public review process. Reclamation has attempted to identify potentially contemporaneous and future cumulative actions in Section III and, to the greatest extent practicable, has provided cumulative effect discussions for each ESA-listed species discussed in Section IV of this document. The diversion and distribution of entitlement waters in the United States is discussed in Section III as contemporaneous and future cumulative actions.

The FWS Draft Endangered Species Consultation Handbook (November 1994) defines "Direct Effects" as encompassing the direct or immediate effect of the project on the species or its habitat. Additionally the handbook states "Direct effects result from the agency action including the effects of interrelated actions and interdependent actions." Direct effects are discussed for each ESA-protected species in Section IV.

Based on comments provided via written reviews of the March 1996 draft of this document, additional relevant reports have been cited in this document. FWS has been provided copies of all written public comments on the draft BA. Additionally, FWS is aware of its recovery plans and FR notices of proposed and final notices of listings and critical habitat designations for the species and critical habitats included in this BA and previous formal section 7 consultations.

Reclamation will also provide sets of maps depicting the most recent (1994) vegetation classification and front work and levee system features for FWS reference.

Due to the considerable interest that a variety of stakeholders have shown in this section 7 consultation on lower Colorado River operations, Reclamation has committed to making the consultation process with FWS fully public. Normally, such section 7 consultations are conducted only between the action agency and FWS. The final biological opinion from FWS on this consultation is scheduled for April 15, 1997. A Consultation Agreement, which outlines a schedule of events and provides for public involvement, was signed on March 29, 1996, by representatives of Reclamation and FWS; a copy of that Agreement is provided as Appendix B.

Pursuant to commitments in the Consultation Agreement, Reclamation provided a 30-day public review and held a public meeting (May 3, 1996) on the March 1996 draft BA. A summary of the public meeting and copies of the 29 written comments on the draft BA have been distributed (via memo dated June 10, 1996) to stakeholders on Reclamation’s mailing list for this consultation.

Due to the number and technical extent of comments on the March 1996 draft of this document, Reclamation has employed additional resources and time to significantly modify this final BA. This major modification has delayed Reclamation’s completion of the BA and its submittal to FWS for formal consultation beyond the estimated date of June 30, 1996 (Step 3 of Consultation Agreement). FWS was notified of this rescheduling via Reclamation’s memorandum dated June 28, 1996 and verbal communication on July 24, 1996. However, the April 15, 1997, deadline (Step 8, Consultation Agreement) for issuance of the final biological opinion will not be changed.

Chapter I TOC | Chapter II TOC | Chapter III TOC | Chapter IV TOC
Glossary of Terms and Acronyms | Appendices | Tables | Figures
Assessment TOC | COMMENTS