WSP00927

• File Number: 8407.500
• Description: Platte River Basin - River Basin General Publications - Missouri River
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 1/1/1991
• Author: BOR
• Title: Annual Operating Plans - Western Division System - Power Operations - Water Year 1990-1991
• Water Supply Pro - Doc Type: Report/Study

WESTERN DIVISION SYSTEM
WATER YEAR 1991 - FORECASTED GENERATION AND PUMP ENERGY REQUIREMENTS

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The total Western Division System generation under most probable inflow
conditions is projected to be 1,526,2 gwh (excluding Yellowtail and Mt.
Elbert) for water year 1991. Pump energy requirements are expected to
total 59.4 gwh \ for the System, which results in a net generation of
1,466.8 gwh (excluding Yellowtail and Mt. Elbert).

The System imports one-half of the total Yellowtail Powerplant generation
and this is forecasted to equal 402 gwh for water year 1991. Total System
load for the year is expected to be 2,181 gwh, rangi ng from a low of
140.2 gwh in February to a high of 262,1 gwh in July. Import energy
totaling 404,9 gwh from other interconnections (exluding Yellowtail) will
be required to meet this load requirement. System surplus generation is
expected to total 92. 5 gwh for the water year, peaking at 28.1 gwh in
September.

A reasonable minimum water supply condition for water year 1991 would
result in a total projected generation of 1,294.7 gwh (excluding Yellowtail
and Mt. Elbert) for the System, which is 231.5 gwh less than the generation
produced under most probable inflow conditions. Pump energy requirements
are expected to total 64.3 gwh for the System and this results in a net
generation of 1,230.5 gwh (excluding Yellowtail and Mt. Elbert).

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The import energy from Yellowtail under reasonable minimum inflow
conditions are forecasted to drop to 273.2 gwh for water year 1991. Total
System load is projected to be the same as for most probable inflow
conditions, 2,181 gwh. A total of 677.5 gwh of import energy from other
interconnections (excluding Yellowtail) will be required to meet this load
requirement if reasonable minimum inflow conditions occur. Peak import
energy from other interconnections (exluding Yellowtail) occurs in November
at 94,7 gwh due to the low Colorado-Big Thompson Project generation because
of the Shadow Mountain drawdown for aquatic weed control. System surplus
generation does not occur in any month,

If reasonable maximum water supply conditions occur in water year 1991,
tota 1 System generat ion is expected to be about 1,543.3 gwh (exl udi ng
Yellowtail and Mt. Elbert). This is only 17,1 gwh more generation than the
most probable inflow conditions produce, Pump energy of 63.3 gwh is equal
to that for most probable inflow conditions and results in a net generation
of 1,479.9 gwh (excluding Yellowtail and Mt, Elbert).

Import energy from Yellowtail Powerplant increases substantially under
reasonable maximum water supply conditions to 613,4 gwh, which is 211,4 gwh
more than the most probable inflow condition produces. Total System load
projected for water year 1991 of 2,181 gwh is the same load as utilized for
the most probable i nfl ow condit ion. Import energy from other
interconnect ions (excl udi ng Yell owta i 1) wi 11 be requi red from October
through March and total 329,9 gwh. If reasonable maximum inflow conditions
occur, surplus generation for the System will be equal to 242.1 gwh and
peak at 80.2 gwh in June.