BOARD00670

• Board Meeting Date: 3/26/2001
• Description: WSP Section - Colorado River Basin Issues - Delta and Inadvertent Overrun Accounting Policy Resolutions
• Board Meetings - Doc Type: Memo

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STATE OF COLORAD

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Colorado Water Conservation Board

Department of Natural Resources

1313 Sherman Street. Room 721
Denver, Colorado 80203
Phone: (3D3) 866.3441
FAX: [phone]
www.cwcb.state.co,us MEMORANDUM

Bill Owens
Governor

Greg E. Walcher
Executive Directo

Rod Kuharich
eWeB Director

Dan McAuliffe
Deputy Director

TO:

Colorado Water Conservation Board Members
Randy Seaholm, Chief, Water Supply Protection #

FROM:

DATE: March 23, 2001

SUBJECT: Agenda Item 25e, March 26-27,2001 Board Meeting-
Colorado River Basin Issues - Colorado River Inadvertent Overrun Policy
and Accounting

Backl!round

The June 3, 1963, U.S. Supreme Court opinion in the case of Arizona v California (343
U.S. 546) held that Congress had put the Secretary of Interior (Secretary) in charge of the
water projects constructed by the Federal Govenunent on the Colorado River. Thus, the
Secretary has power to allocate and distribute the waters of the mainstem Colorado River
in accord with Section 4a of the Boulder Canyon Project Act (45 stat. 1057,43 U.S.C.
617)(BCP A). Subsequently, the Secretary has entered into water contracts with entities
in Arizona, California and Nevada pursuant to section 5 of the BCPA.

Article V of the U.S. Supreme Court Decree in Arizona v. California dated March 9,
1964, (376 U.S. 340) requires the Secretary of Interior to compih';'and maintain records of
the diversion of water from the Colorado River mainstem, return flows of such water to
the mainsteIl1, and the consumptive use of such water.

Pursuant to the 1970 Criteria for Coordinated Long~Range Operation of the Colorado
River Reservoirs developed in accord with the Colorado River Basin Project Act of
September 30, 1968, (P.L. 90-537) the Secretary annually consults with the Colorado
River Basin States and issues an Annual Operating Plan (AOP) for the coordinated
operation of Colorado River reservoirs. In conjunction with the AOP and pursuant to 43
CFR part 417, Reclamation requires each Colorado River water user in the Lower Basin
to schedule water deliveries in advance of the next calendar year. Actual records of
diversions, returns and uses are not final until the Decree Accounting is published the
following June.

Given the sequence of events above, during any given calendar year a user may
inadvertently consumptively use more Colorado River water than available to them under
their entitlement. Inadvertent overruns result from the after-the-fact accounting, gage
adjustments, and variations in climate that result in both more consumptive use and less

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