WSP03308

• File Number: 8220.105.I
• Description: Colorado River-Water Projects-Navajo-Environmental Studies
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/26/2004
• Title: Navajo Dam EIS-Draft Bio Opinion-US Fish and Wildlife Service New Mexico Ecological Services Field Office
• Water Supply Pro - Doc Type: Report/Study

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Area Manager
DAAFT

D. Category:
Duration:
Fn'I.jU""l;Y.
E. Category:
Timing:
F. Category:
Level :
G. Category:
Control:

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Flows greater than 2,500 cfs during runoff
A minimum of 10 days between March I and July 31
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Timing of peak flows
Within 5 days of historical mean peak date of May 31
Target base flows (mean weekly)
500 cfs target from Farmington to Lake Powell with 250 cfs minimum release
from Navajo Dam. Range 500-1,000 cfs.
Flood control releases
Handle as a high magnitude, short duration spike and release when flood
control rules require, except that the release shaH not occur earlier than
September 1. If an earlier release is required, extend duration.

Statistics for criteria A-E are measured at the Four Corners Gage. Statistics for criteria F will be
measured using the Three Gage Rule described above. By applying operating rules based on the
Flow Recommendations, depletions shown in Table I are possible.

Depletions
The depletions shown in Table I are for existing private and public projects that affect San Juan
River flows. Some of these projects have undergone section 7 consultation and others have not.
This depletion table was used to develop the Flow Recommendations.

Table 1

Reclamation projects in Table I that wiH require section 7 consultation include the Hammond
Project, the Florida Project, the Pine River Project, and the Mancos Project. Table I also
includes future projects that have undergone consultation and NEP A analysis; these projects
include the Animas-La Plata Project, completion of the Navajo Indian Irrigation Project, and the
Jicarilla Apache Nation water sale to Public Service Company of New Mexico. Depletions due
to evaporation of water from Navajo Reservoir are also included in the table. The depletions that
are portrayed in Table I are either analyzed as part of this document's environmental baseline or
as cumulative effects,

The majority of the depletions shown in Table I are independent of the Navajo Unit; however,
there are both direct and interrelated effects from Navajo Unit depletions. Direct depletions
include:

Navajo Indian Irrigation Project
Navajo Reservoir evaporation
San Juan power plant
Minor depletions (small contracts)

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280,600 af
27,428 af
16,200 af
less than 1,000 af

These depletions, with the exception of the Navajo Reservoir evaporation, have undergone
section 7 consultation. Navajo Reservoir evaporation (average annual depletion of27,428 at)
will be analyzed in this draft biological opinion.

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