WSP11123

• File Number: 8220.100.50
• Description: CRSP - Power Rates
• Basin: Colorado Mainstem
• Date: 4/1/1979
• Author: USDOE/WAPA
• Title: CRSP and Participating Projects - Proposed Power Rate Ajustment
• Water Supply Pro - Doc Type: Publication

explanatory notes for each column. Of significance to note is that on
Figure 6, Table I, and on other figures and tables to follow, the data
for fiscal year 1977 cover a IS-month period. The fiscal years before
that are for the periods July through the next June, and the fiscal
years after that are for the periods October through the next September.

The following paragraphs provide detailed explanations of the
repayment study data, including power revenues and the costs to be paid
by such revenues.

C. CRSP Power Resources and Power Sales, Project capacity and
energy resources are dependent to a large extent on climatic conditions
which affect both the supply of project water and the use of project
water. Project power operations are conducted within the limitations
of the water statutes governing the use of Colorado River water. The
design of the project facilities coupled with reservoir operating
criteria enable the major powerplants to be operated at maximum
capacity during heavy load hours, thus making it possible to market
full plant capacity less operating reserves and less the amount
required by project use,

The significant factors involved in the repayment study in
regard to capacity and energy resources and power sales are discussed
below.

1, Hydrological Basis for Estimating Project Generated
Energy. For fiscal years 1964 through 1977, actual generation data
were used. The hydrological analysis used for projections of projeet-
generated energy after fiscal year 1977 was based on runoff and depletion
records for the Colorado River drainage system above each of the
reservoir sites for the period 1906 through 1977. Using these records
and subtracting estimated future depletions, fourteen 72-year sequences
of operation were run for each season (summer and winter) of future years.
In the first sequence, the water supply for the starting year of 1978 was
assumed to be equal to that of the year 1906 (except as modified by
depletions), In the second sequence, the water supply for the starting
year of 1978 was assumed to be equal to that of the year 1911 (as
modified by depletions). The other sequences were run similarly using
S-year intervals to determine the water supply for the starting year of
1978 until in the fourteenth sequence, the water supply for 1978 was
assumed equal to that of 1971 (as modified by depletion), The averages
of the fourteen sequences for each season of each future year were
construed to represent a reasonable estimate of the future average
generation per season.

Figure 7 shows the historical flow at Lee Ferry, Arizona, for
the period 1896 through 1977, It will be noted from this that, in
the 14 years since start of generation by the CRSP powerplants (water
year 1964), there have been 4 years of flow above and 1 year equal to
the long-time average.

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