WSP04624

• File Number: 8220.145.A
• Description: La Plata Project ‎(New Mexico)‎
• Basin: San Juan/Dolores
• Date: 4/1/1944
• Author: USDOI/BOR
• Title: La Plata Project: Colorado-New Mexico - Project Investigations Report No. 32-A
• Water Supply Pro - Doc Type: Report/Study

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CONCLUSIONS

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Summary of Findings

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There are some 20,000 acres in Colorado and 3,800 acres in New
Mexico now inadequately irrigated from unregulated streamflow of La
Plata River. Farming operations carried on since 1875 have demon~
strated that soil and climate are sattsfactory for permanent agri-
culture providing that an adequate irrigation water supply is avail-
able.

Water supply is inadequate for the area under ditches. Shortages
have been particularly severe since 1928, and, together with low prices
for farm products, have resulted in a decrease in farmed area and live-
stock, and abandonment of many farms. At one time over half the popu-
lation of the project was receiVing relief of some kind.

Supplemental water must be provided if the present irrigated area
is to be successfully farmed and the farm population retained. Such
supplemental water supply can be developed only by storage of waters
of the La Plata Basin as the cost of importation from adjacent basins
is excessive.

An active storage capacity of 12,000 acre-feet at the Long Hollow
Reservoir site and 12,000 acre-feet for irrigation at the State Line
site plus provisions for silting and ror flood control at the latter,
which would increase the desirable capacity at the State Line site to
32,000 acre-feet, is the most attractive development.

The two reservoirs properly operated would substantially improve
the water supply to both states, as to both quantity and distribution,
and would utilize the entire run-off in periods of low flow. The pres-
ent irrigated area of 3,800 acres in New Mexico would usually receive
an adequate and ideally distributed water supply, with the aid of State
Line Reservoir. When State Line Roservoir is empty, stream operations
would be conducted, as at present, in accordance with the compact.

:the supply for Colorado lands would be greatly improved by storage
of surplus flows and regulation of flood water now diverted under de-
creed rights.

The average annual increase in gross crop values with the improved
water supply would amount to about $19 per acre for the Colorado lands
to be included in the project and $11 per acre for the New Mexico Innds.

The estimated cost of construction is $1,474,000 for the Colorado
division and $2,326,000 for the New Mexico division, or a total of
$3,800,000. Of this total, $400,000 can be allocated to the flood con-
trol benefits in New Mexico, and in a 40-year interest-free repaymont
period, $593,600 can be repayed by the Colorado irrigators and $273,600
by the New Mexico irrigators.

Recommendations

The project is desirable and urgently needed to stabilize the looal

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