WSP08299

• File Number: 8141
• Description: Fryingpan-Arkansas Project
• State: CO
• Basin: Arkansas
• Water Division: 5
• Date: 1/1/1969
• Author: US DoI BoR
• Title: Flood Control Fryingpan-Arkansas Project Eastern Slope Features
• Water Supply Pro - Doc Type: Report/Study

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period. However, large increases of crop yields are expected as a
result of technological advances and improved farm management, and in
consideration of the currcnt and pending developments, most of the in-
crease in production should take place in the early part of the period.
According to the publications of the U,S. Department of Agriculture,
A 50-Yeal' Look Ahead at U.S. Aql'l:cultul'e, June 1959; and Agricultural
Economic Report No. 33, Long-Te)~ Production Pl'ospects fol' Westel'n
Agl'icultul'e, May 1963, there "ill be substantial increases in crop
yields in the United States ovcr the next SO years. It is reasonable
to assume that there "ill be further technological advances after this
time so that over a 100-year period there will be a large increase in
average yield per acre. Based on a 1957-59 average index of 100 for
crops produced in the Arkansas River Basin, the index of production in
the United States is expected to be 113 in 1975 and 160 in 2010. Ex-
trapolation of the 1975 to 2010 rate to the year 2060 yields an index
of 265 or an increase over 1957 of 165 percent. The increasc between
1960 and 2060 would be 163 percent. For Colorado the index figures for
thc years 1975, 20]0, and 2060 are 119, 169, and 2RO, respectively.
The increase in average yield pcr acrc will be 180 percent. It is esti-
matcd that crcp production in the Arkansas River flood plain in 20hO
will be about 2032 tiGICS tllat of ]960 or ~n increase of 13~ percell!.
This percclltagc is hased on an average yield pcr acrc index of 100 in
1960; 126 in 1975; and 176 in 2010. It is cxpected that thc incrcase
in per acre yields bet"een 2010 and 20hO "ill be at a decreasing rate
so that thc 2060 index will be only 232. Thc increase betHeen 1960 and
2060 would be 132 percent. This overall increase of 132 percent ad-
justed to an average annual cquivalent recognizing a faster growth rate
in the initial years of project operations results in a groHth factor
of 85 percent.

89. During a likc period, population Hi thin the flood plain of
the Arkansas River is also expected to increase, but at a lesser groHth
ntethan ,a~ricultural product-ion. jt is -estimated that the 2060 popu-
lation of the basin above thc Purgatoire River Hill be about 4.25 times
the 19hO population wnich "ould he a 325 percent increase. Population
projections shown on plate 8 indicate that most of the groHth Hould
occur during the latter part of the period. Adjusting the nonunifo:nn
growth rat~ to reflect the deferrcd growth, yields an average annual
equivalent rate of 0.7R. Further adjustment of the basin factor to
reflect groHth only in the flood plain results in a gro"th factor of
40 percent. Gro"th in the area, other than increased agricultural
production, will likely be directly or indirectly related to increases
in population. Consequently, gro"th that would take place in the flood
plain, other than crops and some cconomically stable developments, "ould
occur at the same rate as population exp;msion.

90. Benefits to future dcvelopmcnts arc tabulated in table 12, and
are estimatcd to be $181,400. This is ahout 32 percent of benefits to
existing developments that "ould be benefitcd. As indicated in the
table, thcre "ould be no significant bencfit from this sourcc in the

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