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

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

1506

phreatophyte consumption for the entire mainstem downstream of the

reservoir, and second, the total irrigation demand for all of the

initially identified PIA parcels except Parcel Ml16. Inflows

during the irrigation months in excess of the releases required to

meet downstream demands and all inflows in the non-irr igation months

were stored in the reservoir or spilled. Losses due to evaporation

were deducted from reservoir contents.

The computer simulations were iterated, reducing the reservoir

capacity 100 AF each run, until the smallest reservoir that did not

resul t in a shortage in supplying the ir r iga tion demand was

determined. For Case I, the full-supply condition, the required

size of reservoir was 7,200 AF. An annual summary of the final Case I

simulation run for the 7,200 AF reservoir is contained in Appendix

D.3.

The simulations for Case II were essentially identical to those for

Case I, except the reservoir size was decreased until the smallest

size was found that did not result in irrigation supply shortages

that exceeded the adopted acceptable shortage criteria. For Case

II, the acceptable shorted supply condition, the required size of

reservoir was 4,400 AF. An annual summary of the final Case II

simulation run for the 4,400 AF reservoir is contained in Appendix

D.3.

It was presumed that the residual payment capacity of even the best of

3l