8031

• UCREFRP Catalog Number: 8031
• Author: U.S. Department of the Interior.
• Title: Fish and Wildlife Service Final Biological and Conference Opinion on Lower Colorado River Operations and Maintenance - Lake Mead to Southerly International Boundary.
• USFW Year: 1997.
• USFW - Doc Type: \
• Copyright Material: NO

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BIOLOGICAL OPINION

Proposed Action

that it can be passed through Glen Canyon Power plant when operated at the available capability
of the powerplant. Any water thus retained in Lake Powell to avoid bypass of water at the Glen
Canyon Powerplant will be released through Glen Canyon Powerplant as soon as practicable to
equalize the active storage in Lake Powell and Lake Mead."

Reservoir equalization scheduling is assisted by computer modeling simulation with the following
steps. First, the model computes the quantity of 602(a) storage required by the criteria. Next, the
model predicts the End Of Water Year (EOWY) contents of Lake Powell, Lake Mead, and the sum
of Upper Basin reservoirs. Next, the model makes two checks to see if the reservoirs should be
equalized: 1) if the sum of Upper Basin reservoir contents is greater than the 602(a) storage
quantity, and 2) if the predicted EOWY contents of Lake Powell are greater than the predicted
EOWY contents of Lake Mead; then the contents of Lake Powell and Lake Mead are equalized by
releasing water through Glen Canyon Dam.

b. Interstate and international waters

Fig. 2, above, and Fig. 5 illustrate the LCR water that is released and diverted yearly. Based on
the Law of the River, entitlements to the beneficial use of Colorado River water in the lower basi n
have been established in the following four ways.

· Court decrees for 4,156,847 acre-feet which includes the water rights perfected by the
States (which existed prior to the effective date of the Boulder Canyon Project), Indian
reservations water entitlements, and other Federal entitlements listed in the Court decrees.

· Secretarial reservations for Federal uses, such as the Bureau of Land Management, Fish
and Wildlife Service, and Reclamation.

· Contractual entitlements under section 5 of the Boulder Canyon Project Act.

· The International Treaty with Mexico for 1.5 maf.

The 1964 United States Supreme Court Decree in Arizona vs. California, in Article II, states "The
United States, its officers, attorneys, agents and employees are hereby severally enjoined from
releasing water controlled by the United States for irrigation and domestic use in the States of
Arizona, California and Nevada, except as follows:

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