WSP12929

• File Number: 8282.600.40
• Description: 2004 Annual Operating Plan
• Basin: Colorado Mainstem
• Author: Lower Colorado Region River Operations Group
• Title: 2004 Annual Operating Plan Reservoir Information Operation Study
• Water Supply Pro - Doc Type: Data

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To: All Annual Operating Plan Recipients

From: Lower Colorado Region
River Operations Group
Attention: BC004600
P.O. Box 61470
Boulder City, NV 89006-1470
Phone: [phone]

This operation study reflects the 2004 Annual Operating Plan (AOP) as signed by the Secretary of Interior. The Partial
Domestic Surplus condition is the criterion governing the operation of Lake Mead for calendar year 2004. A copy of the
2004 AOP can be obtained by contacting Lorraine Siano, [phone] or visit our website at
www.usbr.gov/lc/region/lcrivops.html.

Diversion and use schedules in this study are based on water orders submitted to Reclamation and are subject to change.
Diversions in CY 2004 by the Metropolitan Water District of Southern California (MWD) and the Central Arizona Project (CAP)
are projected as being 0.581 million acre-feet (maf) and 1.634 maf, respectively. Consumptive use above Hoover is
projected as being 0.292 maf.

Lake Mead's elevation is projected to be 1124.80 feet at the end of calendar year 2004. Based on this projection, we are
assuming normal diversion and use schedules for calendar year 2005. The actual determination of the criterion governing
the operation of Lake Mead for calendar year 2005 will be based on the August 24 Month Study, per the Interim Surplus
Guidelines.

Lake Mead's elevation is projected to be 1118.44 feet at the end of calendar year 2005. Based on this projection, we are
assuming normal diversion and use schedules for calendar year 2006.

As of 5/04/04, due to the current elevation of Lake Mead, Hoover's generating plant effective capacity has been changed to
1767 MW. Unit capacity tests will be performed as lake elevation decreases in 2' increments. Davis generating plant
effective capacity has changed to 255 MW. This study reflects these changes in the projections.

Current runoff projections into Lake Powell are provided by the National Weather Service, Colorado Basin River Forecast
Center and are as follows: observed unregulated inflow into Lake Powell for the month of May was 1.180 maf or 51% of the
30 year average. The forecast for the month of June unregulated inflow into Lake Powell is 1.020 maf or 33% of the 30 year
average. The projected April through July unregulated inflow for water year 2004 is 3.4 maf or 43% of average.

Hoover, Davis, and Parker historical gross energy figures come from form PO&M from the Power and O&M Group, Boulder Canyon
Operations, Bureau of Reclamation, Boulder City, Nevada. Questions regarding these historical numbers can be directed to
Joe Donnelly, [phone].

(Note: lower basin previous months historical SNWS and flow to Mexico values are preliminary estimates.)