WSP10995

• File Number: 8220.101.09
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 12/21/1994
• Author: USDOI-USFWS
• Title: Final Biological Opinion-Operation of the GlenCanyon Dam as the Modified Low Fluctuation Flow Alternative of the Final Environmental Impact Statement-Operation of Glen Canyon Dam
• Water Supply Pro - Doc Type: Biological Opinion

2-21-93-F-167

FINAL BIOLOGICAL OPINION
MODIFIED LOW FLUCTUATING FLOW ALTERNATIVE
DRAFT ENVIRONMENTAL IMPACT STATEMENT
OPERATION OF GLEN CANYON-DAM

INTRODUCTION

This biological opinion is in response to Bureau of Reclamation's (Reclamation) original request
of February 5, 1993, for formal section 7 consultation, under the Endangered Species Act (Act)
of 1973, as amended, with the Fish and Wildlife. Service (Service) on the proposed action to .
operate Glen Canyon Dam according to ,operating and other criteria of the ,Modified Low
Fluctuating Flow Alternative (MLFF), selected as the preferred alternative for the Final
Environmental Impact Statement (EIS), and described in the January 1994 Draft EIS, Operation
of Glen Canyon Dam and, modified by memorandum dated June 17, 1994 (U.S. Bureau of
Reclamation 1994). Glen Canyon Dam, shown in Figure I, is located in Coconino County,
Arizona.

The species of concern in this opinion are the endangered bald eagle (Haliaeetus leucocephalus),
humpback chub (Gila cypha) , Kanab ambersnail (Oxyloma haydeni kanabensis), peregrine falcon
(Falco peregrinus anaJum), and razorback sucker (Xyrauchen texanus). Critical habitat was
listed for the humpback chub and the razorback sucker on March 21, 1994 (U.S. Fish and
Wildlife 1994a). A document providing additional information about the designation of critical
habitat was made available in September 1993 (U.S. Fish and Wildlife Service 1993a). In
addition, the southwestern willow flycatcher (Empidonax traillii extimus) was proposed as an
endangered species with critical habitat on July 23, 1993. Because Reclamation is still
evaluating the effect of the proposed action on the southwestern willow flycatcher, the Service
will address the section 7 responsibilities for that species in a later conference report.

Formal consultation began on February 8, 1993, the date your request was received by the
Service. Reclamation and the Service agreed to an extension of time''to prepare the draft
biological opinion which was provided to Reclamation on May 20, 1993. Reclamation and the
Service discussed the draft reasonable and prudent alternative on May 21, 1993. Reclamation
requested a technical review of the recommended flows which was conducted by the Glen
Canyon Environmental Studies (GCES) Senior Scientist and Program Manager on June 11.

Reclamation confirmed on June 10 the mutual agreement to extend the consultation period to
coincide with the final EIS and pro:vided comments to the Service on the May draft biological
opinion on August 16. The Service provideda'final'draft biological opinion on October 13 and
Reclamation made the draft available for public review. A .technical review of the final draft,
requested by Reclamation, was facilitated by the. GCES Senior Scientist on March 2,. 1994.

IS December 1994 final biological opinion 1-11-93-F-167

,
.~
,.
,
j

'?"

":~

<

';.

....-..

'''-.
:J,

~'-"'
-jj
:.~:
~~:
;;;;
"-:

~~ ~.

~t
,,:~.
~:'~:

, .
L',_

'>~.
r::

f;~~<

~.:{::
r~
i'~~
>;

if,:
Ji,(
~~:
(~F
:Hf
f~
-;~
'~..,~
Co.>,
;'t'"",
~,,::~:
:'"'--"
"".;
,.... .

I