BOARD00148 ‎(2)‎

• Board Meeting Date: 3/12/2007
• Description: WSP Section - Colorado River - DEIS - Development of Lower Basin Shortage Guidelines and Coordinated Management Strategies for Lake Powell and Lake Mead, Particularly Under Low Reservoir Conditions
• Board Meetings - Doc Type: Memo

.
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
. 18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
. 35

Executive Summary

Environmental Consequences

ES.1 Background

The Secretary of the United States Department of the lnterior (Secretary), acting through the
Bureau of Reclamation (Reclamation), proposes to adopt specific interim guidelines for
Colorado River Lower Basin (Lower Basin) shortages and coordinated operations for Lake
Powell and Lake Mead, particularly under drought and low reservoir conditions.

Reclamation, as the agency that is designated to act on the Secretary's behalf with respect to
operation of Glen Canyon Dam and Hoover Dam and managing the mainstream waters of the
lower Colorado River pursuant to federal law, is the lead federal agency for the purposes of
compliance pursuant to the National Environmental Policy Act of 1969 (NEP A) for the
development and implementation of the proposed interim guidelines. Five federal agencies are
cooperating for purposes of assisting with environmental analysis and preparation of the Draft
EIS. The cooperating agencies are the Bureau of Indian Affairs (BIA), United States Fish and
Wildlife Service (FWS), National Park Service (NPS), Western Area Power Administration
(Western), and the United States Section of the International Boundary and Water Commission
(USIBWC).

The Draft EIS includes six chapters as outlined below:

. Chapter 1: Purpose and Need;

. Chapter 2: Description of Alternatives;

. Chapter 3: Affected Environment;

. Chapter 4: Environmental Consequences;

. Chapter 5: Other Considerations and Cumulative Impacts; and

. Chapter 6: Consultation and Coordination.

ES.1.1 Purpose and Need for Action
During the period of 2000 through 2006, the Colorado River Basin experienced the worst
drought conditions in approximately one hundred years of recorded history. During this
period, storage in Colorado River reservoirs has dropped from nearly full to less than 60
percent of capacity at the end of2006. Currently, the Department of the Interior
(Department) does not have specific operational guidelines in place to define the
circumstances under which the Secretary would reduce the annual amount of water available
for consumptive use from Lake Mead nor to address the coordinated operations of Lake
Powell and Lake Mead during drought and low reservoir conditions.

The purpose of the proposed federal action is to: 1) improve Reclamation's management of
the Colorado River by considering tradeoffs between frequency and magnitude of reductions
of water deliveries, and considering the effects on water storage in Lake Powell and Lake
Mead, and on water supply, power production, recreation, and other environmental

Draft EIS - Colorado River Interim Guidelines for
Lower Basin Shortages and Coordinated Operations
for Lake Powell and Lake Mead

ES-1

February 2007