WSP05551

• File Number: 822.600.10
• Description: Colorado River Annual Operating Plan - Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/2002
• Author: USDOI/BOR
• Title: Annual Operating Plan
• Water Supply Pro - Doc Type: Annual Report

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The determination of surplus conditions for calendar year 2002 is based on these Interim Surplus
Guidelines. Consistent with Article XI, Section 7 of the Interim Surplus Guidelines, the August
24-Month Study was used to project the January 1,2002, Lake Mead reservoir water surface
elevation. Based on this projection, the Full Domestic Surplus will govern releases for use in the
States of Arizona. Nevada., and California during calendar year 2002, as defined in Arliele Xl,
Section 2 of the Interim Surplus Guidelines, The amount of this Surplus shall equal:

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a.

For Direct Delivery Domestic Use by MWD, },250 MAF reduced by the amount
of basic apportionment available to M\\'D.
For use by SNW A, the Direct Delivery Domestic Use within the SN\V A service
area in excess of the State of Nevada's basic apportionment
For use in Arizona. the Direct Delivery Domestic Use in excess of Arizona's basic
apportionment.

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b.

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c,

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For informational and planning purposes, Reclamation has estimated the amount of surplus water
expected to be pumped or released from Lake Mead during calendar year 2002 under the Full
Domestic Surplus. It is not expected to exceed 0.640 MAF (789.44 t\-lCM), The actual amount
of surplus could be less than this amount (in the likely event of the use of any available unused
apportionment) and could also, based on actual Direct Delivery Domestic use, exceed this
projected amount.

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As provided in Article Xl, Section 3 of the Interim Surplus Guidelines, the Secretary shall
undertake a "mid-year review" pursuant to Article 1(2) of the Operating Criteria, allo\N;ng for the
revision of the current ADP, as appropriate, based on actual runotTconditions which are greater
than projected, or demands which are lower than projected. The Secretary shall revise the
determination for the current year only to allow for additional deliveries. Any revision in the AOP
may occur only after a reinitiation of the AOP consultation process as required by law.

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For informational purposes, the natural inflow required to reach a Quantified Surplus (70R value
strategy) on January 1,2002, is 24.892 MAF, which has been exceeded in the historical record
only I percent of the time. As provided in Article IV(I) of the Interim Surplus Guidelines, the
70R strategy involves assuming a 70-percentile inflow into Lake Powell, subtracting out the
consumptive uses and system losses and checking the results to see if all of the water could be
stored or if flood control releases from Lake Mead would be required, Ifflood control releases
from Lake Mead would be required, additional water is made available to the Lower Division
states beyond a full domestic surplus. The notation 70R refers to the natural inflow into Lake
Powell that has been exceeded 30 percent of the time (17.4 MAF),

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1944 U.S.-Mexico \Vater Treat).

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Under most probable inflow conditions, water in excess of that required to supply uses in the
United States \\-;11 not be available, therefore there will be no Colorado River surplus, as defined
by the 1944 U.S.-Mexico Water Treaty, for delivery to Mexico. Vacant storage space in
mainstem reservoirs is substantially greater than that required by flood control regulations.

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October 15, 200 1

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