WSP12329

• File Number: 822.600.10
• Description: Colorado River Annual Operating Plan - Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1995
• Author: USDOI/BOR
• Title: Annual Operating Plan
• Water Supply Pro - Doc Type: Annual Report

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1944 Mexican Water Treatv Deliverv. The guaranteed annual quantity of 1,850 MCM
(1,500 MAF) of water will be delivered to Mexico during calendar year 1995 in
accordance with Article 15 of the 1944 Mexican Water Treaty and Minute No. 242 of the
IBWC.

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199~OPERATIONS SUMMARY AND RESERVOIR STATUS

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/Water year 19~9nalled the return of dry hydrological conditions in the basin.
Basinwide precipitation during 1994 was below average. This lower precipitation also
translated into a below average snowpack. At the beginning of the runoff season the
basinwide snowpack was only 72 percent of average and conditions improved only
slightly through the remainder of the runoff season. Once again a pattern of southerly
storms developed over the basin during the snow accumulation season. As a result, the
northern portion of the basin had well below average snowpack levels, and the central
and southern portion of the basin had below to near average snowpack levels. These
factors combined to produce a well below average runoff in the Green River (42 percent
of average). a below average runoff in the Gunnison and Lake Powell (73 and 58 percent
of average respectively), and a slightly below average runoff in the San Juan Basin
(87 percent of average).

With the low runoff during 1994 there were no reports of flooding at any location during
the water year.

Unregulated inflow into Lake Powell is expected to be 8.365 MCM (6,781 MAp) in
water year 1994, approximately 58 percent of the 30 year average. This inflow, resulted
in the loss of approximately 1272 MCM (1.031 MAF) of storage in Lake Powell.
Approximately the same amount of storage was lost from the upstream reservoirs.
1.205 MCM (0.977 MAF). With an additional net loss of approximately 1,641 MCM
(1.330 MAF) within the Lower Basin reservoirs. the total Colorado storage system lost
approximately 4.118 MCM (3.338 MAF) during water year 1994. It is now estimated
that it would take five years of average inflow to completely fill the storage system.
During 1994. all deliveries of water to meet obligations pursuant to "The Law of the
River" were maintained. Tables l(a) and l(b) list the expected October 1, 1994 reservoir
vacant space. live storage. water elevation. percent of capacity, change in storage, and
change in elevation during water year 1994.

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