WSP07589

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/1978
• Title: Salinity Management Options for the Colorado River -- Part 2 of 2 -- Page 169 - End
• Water Supply Pro - Doc Type: Report/Study

Thble 8-110. Number of acre. available for .ingle and
double cropping by land cia.., Roo.e-
veU Irrigation INtrict.

l\:l
00
(;)
o

Single
Cropped
(Acres)

28,168

Double
Cropped
(Acres)

784

55

2,185

Total
(Acres)

28,952

Land 1
(WeU Drained)
Land 2
(Moderately Drained)
Land 3
(poorly Drained)

Total

2,130

231

30,529

839

31,368

There is a .mall change in the .hadow price of
land clas. 8 as demonstrated in Table 8.116. The
remaining values, however, remain constant over the
TDS interval in question and indicate that salinity has
minimal effect on changes in demand for the different
land classes.

231

Table 8.116 displays the total amount of water
required in the model, number of acre feet used per
acre, and the ratio of total water used to estimate net
profit for each level of TDS. The change in water use
over the interval 776-1400 mg/l Is so smaD that It is
assumed no difference exists. The same can also be
deduced concerning changes in the objective function.
In Table 8-117, seven objective functions vaues are
presented which correapond to the reapectlve levels of
TDS. The total change over the interval (776-1400
mg/l) is only $6,409. It appears that significant
agricultural damages will not be encountered within
the specific TDS range especiaDy in view of the fact
that present water quality in the RID is about 1800
mg/!. Additions of Colorado River water below this
level would improve water quality and benefit its
users. However, when Colorado River water surpas-
ses 1800 mg/!, damages are expected to increment
quite rapidly. In light of the above discussion and the
relatively smaD amount of estimated damages, it is
assumed that the benefits accruing to the Colorado
River supply up to 1800 mg/l are offset by expected
damages from 1800 to 1400 mg/l. Figure 8-19 contains

Table 8.111. Selected crop. I!nd double cropping po.8ibilitie., RooBeveU Irrigation INtrict.
Double Cropping Possibilitiesa
Crops
Wheat Barley Lettuce Sorghum Silage
Alfalfa
Cotton x x x
Barley
Wheat
Sorghum x x x x x
Lettuce x x x x x
Alfalfa Seed
SUage x x x x x
Pasture
Sugar Beets

aCrops under these columns are those assumed to lead in the double cropping rotation.

Table 8-11'. YieldB of mnJor crop. in the Roo.eveU Irrigation INtrict, 1969.1978 (t01lBlacre).

9S Percent
1969 1970 1971 1972 1973 Confidence
Interval ,
Alfalfa Hay 6.00 6.00 6.00 6.00 6.00 6.00:1: 0
Ensilage (Sorghum 26.00 :I: 7.29
or Corn) 35.00 22.00 28.00 20.00 25.00
Barley 1.70 1.99 2.11 2.14 2.26 2,04 :I: 0.26
Wheat 1.86 2.25 2.55 2.70 3.24 2.52 :I: 0.64
Upland Cotton 2.25 2.0 2.20 2.40 2.40 2.25:1: O.21a
Upland Cotton Seed 1.00 . 1.00 1.00 1.00 1.10 1.02 :I: 0.06
Sugar Beets 19.00 15.00 23.10 22.50 22.50 20.42:1: 4.27b
Irrigated Pasture 6.30 6.00 6.10 6.00 6.10 6.10:1: 0.17
Lettuce 10.28 10.25 13.20 It.25 N/A 11.24 :I: 2.20
Sorghum 2.18 2.24 1.82 1.65 2.35 2.05 :I: 0.37
Alfalfa Seed 2.0 2.0 1.0 1.67 :I: 1.06c
a480~pound bales per acre.
b Animal unlt months.
cRundred weight.
Source: Data from Roosevelt Irrigation District Crop Reports.

192