WSP09492

• File Number: 8541
• Description: San Luis Valley Project
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 1/1/3000
• Title: Economic Size of Reservoir for Irrigation Purposes
• Water Supply Pro - Doc Type: Report/Study

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advisable if purrping in the heavily farmed area north of Monte Vista

is oontemplated. Aooordingly, some other plan of utilizing some ground

water storage was sought. Af'ter muoh oonsideration it we.s conoluded

that pumping. from the ground water might be acoomplished east of the

heavily farmed area north of Monte Vista and west of the irrigated area.s

in the vioinity of Mosca ani Hooper. Pumping could be accomplished in

this area without affeoting the" subbing" praotice in either area in all

probability. Pumped water could be dumped into cane.ls already serving

the areas to the east. The amount that oould be utilized would approaoh

60,000 acre feet and the demand on the river at Del Norte reduoed by en

equal amount. The ideal demand had previously been estimated at 670,000

aore feet, but by supplying up to 60,000 aore feet of this demand by

pumping, the amount by which the demand on the river is reduced could be

put to various uses.

The results of the operation studies caused a new look to be taken

at depletions allowable under the terrr.B of the Rio Grande Compact. The

study of the depletions indicates that the new demand on the river of

608,200 acre feet is more in line with Compact provisions. See attached

table of computations.

Studies were made for reservoir capacities of 300,000; 500,000;

and 700,000 acre feet at the Gerrard and Wagon 1"Iheel Gap sites for

irrigation purposes alone. Compact oompliance was computed at the

.New 1~xico State Line. The shortages relieved by each reservoir size at

each site were then computed by evaluating the supply furnished against

the estimated ideal. Historical shortages were computed in the same
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