WSP09467

• File Number: 8281.990
• Description: Colorado River Studies and Investigations -- Webster Hill Dam and Reservoir
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/2001
• Author: Brown and Caldwell
• Title: Technical Memo NO 4A: Analysis of Alternative 4 - New Storage Facility at Webster Hill Site - Mainstem Colorado River
• Water Supply Pro - Doc Type: Report/Study

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CONCLUSIONS AND RECOMMENDATIONS

The following conclusions and recommendations are based on the above results and analysis:

1, There appears to be sufficient legal and physical availability of water under a junior right
for diversion to storage at the Webster HilI site to result in a yield of 40,000 acre-feet per
year in those years in which the 20,000 acre-feet release for recovery of the endangered fish
would be required. The 28,909 acre-feet reservoir could be expected to refill during late
June, July and August under a junior refill right to permit a second release of 20,000 acre-
feet release in late summer or early fall.

2. Hydropower revenues from the 10mw installation would significantly reduce the cost of
releases for the endangered species to approximately $6.40 per acre-foot.

3. The opinions of probable cost developed herein are preliminary and would need additional
refinement.

4. The Webster HilI site with a hydropower installation appears to be a feasible reservoir site
from an economic perspective. Before concluding that this is a feasible alternative for
supplying stored water for making the 20,000 acre-feet releases, it is necessary to complete
additional investigations including:

· Right of way availability and estimated cost.
· More detailed cost investigation for relocating the gas wells.
· More detailed cost investigation concerning electrical transmission capacity available to
the site and cost of providing necessary transmission capacity to the site.
· Necessary environmental investigations concerning the site.
· A detailed site investigation and materials availability investigation would be necessary
to confirm engineering feasibility.

5. Before doing additional analysis, the U.S. Fish and Wildlife Service should be asked for a
determination of their possible acceptance and approval of constructing a 28,909 acre-feet
reservoir at the Webster HilI site and the operation of this reservoir for making releases of
stored water for recovery of the endangered species of fish.

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