WSP01685

• File Number: 8507
• Description: Rio Grande Basin
• State: CO
• Basin: Rio Grande
• Date: 7/27/1970
• Author: US Dept of Ag/CWCB
• Title: Plan of Work - Rio Grande Basin in Colorado
• Water Supply Pro - Doc Type: Report/Study

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paramount. Information from the U. S. DepBrtment of Agriculture will
fill the gap between farm-by-farm conservation operBtions information and
the large project type information now Bvailable or to be made available
by the Bureau of Reclamation, Corps of Engineers, RC&D Area, and other
Federal agencies. The U. S. Department of Agriculture needs information
concerning opportunities and need for development of water and related
land resources in sub-watersheds of 250,000 acres or less within the
basin for development by local organizations with assistance from the
Department under the provisions of the Watershed Protection and Flood
Prevention Act (PL 566, 83d Congress, as amended) and the protection and
development of national forest resources of the basin.

DESCRIPTION OF BASIN

The Rio Grande River Basin in Colorado lies in the south-central part of
the State. It encompasses all or parts of nine counties: Mineral,
Hinsdale, Saguache, Rio Grande, Alamosa, Archuleta, Conejos, San Juan,
and Costilla. It is more than 7,500 square miles in Brea. It is Bbout
140 miles in length east to west Bnd neBrly 100 miles north to south.
The basin opens to the south in New Mexico. It is bounded on the west
and north by the San Juan Mountains and other lesser ranges of the
Continental Divide. On the east it is bounded by the Sangre de cristo
Range. Included is that part of the San Luis Valley locally known as the
"closed basin" encompa.ssing approximately 3,000 square miles without a
defined surface outlet and isolated from the Rio GrBnde drainage by a
low-lying ridge several miles in width.

Precipitation varies from more than 50 inches in the high mountains to
about 8 inches in the San Luis Valley. Average annuBl'snowfall ranges
from about 28 inches in the valley to more than 400 inches on the higher
mountain peBks. Growing seasons in the valley range from 100 to 110 days
for more hardy crops such as grains, hay and pasture, and 80 to 90 days
for less hardy vegetable crops. Frost-free seasons fluctuate widely from
the averages and hBve been recorded less than 30 days. Valley soils are
predominantly coarse to medium textured underlain by sands and gravels
with finer textured silts and silty clays Bppearing in lower areaS in the
center of the closed basin.

Agricultural crops, livestock, minerals, timber, tourism, and outdoor
recreation are the basic economic resources of the basin. Returns from
crop and livestock production are Bbout equal in value. Crops produced
are small grains, hay and pasture, potatoes, and vegetables. Irrigation
of crops is essential because of low precipitation. Agriculture and
natural resources have attracted some industry including processing
plants, manufacture, goods and services, construction, tourist and recre-
ation. Timber and other forest products contribute to the economy with
two sawmills a.t South Fork, one near Saguache, one near Antonito, one at

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