WSP00697

• File Number: 8200.750
• Description: San Juan River General
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 3/1/1960
• Author: Clifford H Jex
• Title: Report on Stream Depletion of the San Juan River Basin in Colorado - March 1960
• Water Supply Pro - Doc Type: Report/Study

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003261

Present Water Use

The principal water use is irrigation. Other use includes municipal

for the Town of Hancos and domestic for the concessionaire of the lIesa

Verde National Park.

A study conducted by the Bureau of Reclamation in 1936 gave 9,920

acres as the area then irrigated by runoff of Mancos River. A field check

of land cleared for irrigation in recent years, supported by farm unit

work maps of the U.S. Soil Conservation Service, indicates the irrigated

land now totals 11,000 acres. This is an increase of 11% in the twenty-

three-year period, 1936-1959. The increase is the result of the regulated

water provided by the Jackson Gulch Reservoir.

The estimated present stream depletion of the Mancos River is given

in Table XXIII.

TABLE XXIII

Average annual stream depletion by irrigation .......
Average annual stream depletion by reservoir
evaporation... , . ., .. ...... , .. ......... ... ... .. ,.
Average annual stream depletion by municipal use...,.

15,400 acre feet

700
100

"
"

"
"

Total

16,200 Acre Feet

Potential \lIater Use

The Hancos Project (with the Jackson Gulch Reservoir as the principal

feature) which was constructed by the Bureau of Reclamation and placed in

operation in 1950, provides for the full utilization of the usable runoff

of the Mancos River. Rights to the use of 1,942 acre feet, or approximately

20% of the storage capacity of the Jackson Gulch Reservoir, remains unallo-

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