PROJ00040

• Contract/PO #: C153446
• Contractor Name: Grand Mesa Water Conservancy District
• Contract Type: Grant
• Water District: 0
• County: Delta
• Bill Number: XB 99-999
• Loan Projects - Doc Type: Feasibility Study

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of outflows from Tongue Creek into the Gunnison River. Most of the outflows
occurred in the spring months of high flows.

One important aspect of the proposed operation of the basin was that irrigation
demands would be met first in the upper service area by the streamflows and local
return flows. Remaining stream flows and generated return flows were then applied
to meet the lower service area demands. If during one particular month these
demands were met and water was still present in the stream, the amount was
marked as surplus water. If this water was present in the stream in the upper
service area, then it was shown as available for storage in the proposed reservoir.
If during one other month a portion of the demands in the lower service area could
not be met from the stream and return flows, then that amount was shown as to be
replaced by the proposed reservoir.

For the Leroux Creek basin, studies made by the USBR quantified water available
for development upstream from the site where surplus water could potentially be
diverted to the basin of Tongue and Surface Creeks, via an extension of Overland
Ditch. The USBR studies covered the years of 1941 to 1966. The consultant
extended the USBR data by generating quantities available for development from
1967 through 1984, in years of low, normal, and high stream flows.

With regard to water available for development in the basins of streams which are
intercepted by Overland Ditch (these streams contribute water to the ditch), the
USBR once studied a possible Grand Mesa Canal which, if constructed, would have
conveyed surplus water from the intercepted streams to the Tongue Creek basin.
The Grand Mesa Canal, as considered by the USBR, would have followed a route
generally parallel to Overland Ditch. The USBR determined quantities of water at
each intercepted stream which would be available for inter basin transfer via the
Grand Mesa Canal. Essentially, the same quantities would also be available for
interbasin transfer by way of the existing Overland Ditch, given the generally
parallel routes of the two canals. The USBR study covered the years of 1941
through 1966. The USBR findings were extended to include the years from 1967 to
1984, for years of low, normal, and high stream flows.

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