WSPC06079

• File Number: 8064.100
• Description: Ute Tribes
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 6/1/1987
• Author: Boyle Engineering
• Title: Agricultural Engineering Study - Mancos Watershed - Task D-E - Final Report - Design-Cost Estimate for Off-Farm Irrigation Facilities and PIA Determination
• Water Supply Pro - Doc Type: Report/Study

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15;2

Elevation-capacity-area curves, were developed for each of the three

sites and preliminary operafing studies were performed to determine

the total capacity necessary at each site to provide a' full

irrigation supply for the initially identified PIA parcels. The dam

freeboard and spillway size were established by routing of the IDF

and FOF through a full reservoir using the HEC-l Modified PuIs flood

routing computer program. The selected spillway size was the

minimum required to pass either the IDF with one foot of freeboard or

the FOF with no freeboard. Floods at Sites 5 and 8 were estimated by

extrapolation of the derived floods at Site 9.

Because of the relative large size of spillway required at Site 9

compared to the reservoir size, a larger reservoir (configuration

9B), which would provide greater flood surcharge storage and allow a

corresponding smaller spillway, was also analyzed.

Rough estimates were made of the major quantities and appraisal-

level cost estimates of the four alternative reservoir

configurations were prepared. The comparative results are shown in

Table 0.9.

It was concluded that Site 9 is the most feasible location and the

small reservoir/large spillway configuration is the most

economical. This site and configuration were adopted for the final

detailed evaluations of the cost of storage. Table 0.9 indicates

that the cost for storage water from a reservoir at Site 9 is more

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