WSPC07505

• File Number: 8040.950
• Description: Section D General Studies - General Water Studies
• State: CO
• Basin: Statewide
• Date: 4/30/1982
• Title: High Plains Study - Six-State High Plains Study Recommendations - With Response
• Water Supply Pro - Doc Type: Report/Study

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SUBJECT TO REVISION

effects may be negative because of siltation and draining of wetlands and loss of cover
and terrestrial habitat. It is expected that development of sandhills areas for irrigation
will adversely affect some wildlife species. Most wildlife species do not fare extremely
well in intensively cultivated areas; however, the !;lo!;lulations of some species, such as
the Ringneck Pheasant, have increased significantly in the grain !;lroducing areas of
the High Plains P'ld migratory water fowl seem to use the grain cro!;lS as a source of
fq,oo during the -",turn south in the Autumn season.

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Inter!;lretations and Explanatory Comments

A brief discussion is !;lresented here to futhur explain the nature of the results
of the projections and information developed by the study. In addition, some illustration
is given of the sensitivity of the results to some of the !;lrojection methods, data, and
assumptions.

The Northern Subarea

The northern !;lart of the High Plains study area, including Nebraska, Colorado,
and Kansas has a much larger sU!;lply of Ogallala water in storage. Thus, the analyses
show significant economic development potential in the foreseeable future. However,
most of the opportunity for growth of the irrigation sectors is in Nebraska. This
three-state northern area had nearly 2.7 billion acre-feet of Ogallala aquifer water in
1977. For the Baseline Case analysis, 6.6 !;lercent of the water reserves would be
wi,!hdrawn and used between 1977 and 1990. An additional 12.1 percent to 13 percent
o~,the water reserves of this area would be used between 1990 and 2020 for the
Baseline and voluntary conservation cases respectively, leaving between 2.18 billion
and 2.16 billion acre-feet of water in storage in the area in 2020. However, 51 !;lercent
of Colorado's reserves, 25 percent of Kansas's, and 16 !;lercent of Nebraska's reserves
are projected to have been used by 2020.

The Southern Subarea

The three southern states of New Mexico, Oklahoma, and Texas had smaller
quantities of water in storage than the northern area. From only 367 million acre-feet
in storage in 1977, projected de!;lletion is to 266.6 and 125.7 million acre-feet by 1990
and 2020 respectively, a loss of nearly two-thirds of the 1977 supply.
In comparison to the North, where increased conservation is projected to have
very little eff eet upon the quantity of water used each year, the conservation policies
are projected to make a significant difference in the southern subarea-l0.9 percent
more water would be left in storage in 2020 for the voluntary conservation case, and
29.7 percent more would be left in storage for the mandatory conservation case than
for the Baseline Case. The results of this study show that the northern subarea would
have 9.4 times the quantity of ground-water in storage in 1990 and 17.4 times the
quantity in 2020 than the southern three sta tes will have.

Crop Production

The four major crops best-suited to irrigation in the High Plains, listed in highest
to lowest rank order of value of production in 1977-corn, wheat, grain sorghum, and

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