C150063 Feasibility Study

• Contract/PO #: C150063
• Contractor Name: Jackson Lake Reservoir & Irrigation Company
• Contract Type: Loan
• Water District: 1
• County: Morgan
• Bill Number: SB 94-29
• Loan Projects - Doc Type: Feasibility Study

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officials, the water storage at the reservoir has been based on reservoir gage height
rather than decreed storage capacity. The storage at the decreed gage height is
indicated in a 1 948 vintage chart used for reservoir operation as well as on a filing map
for the reservoir including a proposed enlargement (date unknown). The 1948 chart
indicates a maximum storage of 27,256 acre-feet at gage height 30.0 feet, while the
filing map indicates a maximum storage of 35.445 acre-feet at gage height 30.2. The
1948 storage capacity chart used by the Company and the Water Commissioner for
reservoir operations (shown in Table 4 and on Figure 3) may not reflect water in
storage, but instead indicates water delivery to stockholders, after accounting for
reservoir evaporation and seepage losses during the delivery season (shrinkage). The
1948 chart may therefore understate the actual reservoir storage content. Correction of
these errors, I.e., utilization of the filing map, would appear to increase the historic
record of water in storage and overall utilization of the supplies. Refer to Figure 3 and
. Table 4 for the storage capacity derived from the filing map.

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The reservoir is not currently operating under any fill restriction. The Company
has a self-imposed restriction during the winter and spring months whereby the
reservoir level is held below gage height 27 feet due to potential wave damage at higher
levels. This restriction does not impact storag&, as the^.reservoir has been able to fill in
March or April each year:

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