WSP06774

• File Number: 8282.600.10
• Description: Colorado River Annual Operating Plan
• Basin: Colorado Mainstem
• Date: 12/14/1999
• Author: USDOI/BOR
• Title: 29th Annual Report and 2000 Annual Operating Plan for Colorado River System Reservoirs
• Water Supply Pro - Doc Type: Publication

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Lower Buin Reservoin

Water shall be released or pumped from Lake Mead to meet the foUowing requirements:

(a) 1944 Mexican Water Treaty obligations;
(b) Reasonable benefieial consumptive use requirements of mainstream users in
the Lower Division States;
( c) Net river losses;
(d) Net reservoir losses;
(e) Regulatory wastes; and
(f) Flood control.

The Operating Criteria provide that after the commencement of delivery of mainstream water by
means of the CAP, the Secretary ofthe Interior will determine the extent to which the reasonable
beneficial consumptive use requirements of mainstreant users are met in the Lower Division
States. The reasonable beneficial consumptive use requirements are met depending on whether
a normaJ, surplus, or shortage condition has been determined. The normaJ condition is defined
as annuaJ pumping and release from Lake Mead sufficient to satisty 9,251 MCM (7.500 MAF)
of consumptive use in accordance with Article ill(3)(a) of the Operating Criteria and Article
II(B)(I) of the u.s. Supreme Court decree in Arizona v. California, The surplus condition is
defined as annuaJ pumping and release from Lake Mead sufficient to satisty in excess of 9,25 I
MCM (7.500 MAF) of eonsumptive use in accordance with Article ill(3)(b) of the Operating
Criteria and Article II(B)(2) of the U.S. Supreme Court decree in Arizona v. California.

The current water supply conditions foreeast mandatory flood control releases that are projected
to be above downstreant requirements in January and February of calendar year 2000. Using a
most probable inflow forecast for 2000, flood control releases are aJso projected in the beginning
of calendar year 200 I. Therefore, taking into account (I) the existing water storage conditions
in the basin, (2) the most probable near-term water supply conditions in the basin, and (3) that
the beneficiaJ consumptive use requirements of Colorado River mainstream users in the Lower
Division States are expected to be more than 9,250 MCM (7.5 MAF), the surplus condition is
the criterion governing the operation of Lake Mead for caJendar year 2000 in accordance with
Article ill(3)(b) of the Operating Criteria and Article II(B)(2) of the decree in Arizona v.
California.

While there still is no agreed upon long term strategy for the determination of surplus conditions,
the making of this determination, based on flood control and spill avoidance considerations, does
not preclude the Secretary from adopting other determination eriteria in future years.
Reclantation has initiated the National Environmental Policy Act process and has solicited
comments on the development ofspeeific surplus criteria for management of the Colorado River
in a FederaJ Register notice on May 18, 1999 (64 Fed. Reg" No. 95, p. 27008). Reclantation
continues to work on the development of specific surplus eriteria.

Nothing in the decree in Arizona v. California prohibits the Secretary of the Interior from
releasing water apportioned, but unused, in any Lower Division State for that year for

December I, 1999

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