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<br />Table 8-90. Total a1Id per acre net profit by TDS
<br />leve~ Salt River Project.
<br />
<br />TDS
<br />(mg/l)
<br />
<br />565
<br />900
<br />1100
<br />1400
<br />
<br />Profit
<br />(Dollars)
<br />
<br />26,649,599
<br />26,649,599
<br />26,649,599
<br />26,649,599
<br />
<br />Per Acre
<br />(Dollars)
<br />
<br />160.60
<br />160.60
<br />160,60
<br />160.60
<br />
<br />Table 8.91. Summary statistics, &dt River Project.
<br />
<br />Total Acres
<br />Double Cropped Acres
<br />Annual Total Damages
<br />Annual Per Acre Damages
<br />Annual Damages Per mg/l
<br />Annual Damages Per mg/I Per Acre
<br />
<br />165,942
<br />31,717
<br />$ 0
<br />$ 0
<br />$ 0
<br />$ 0
<br />
<br />River Project. Under the Salt River supplemental
<br />subgroup heading are a number of small districts
<br />representing varius acreages which are: Gila Crossillg
<br />District, Maricopa Garden Falls District, Peninsular
<br />Ditch Company, Salt River Indian Reservation, and
<br />St. Johns Irrigation District (Map 3.10). The
<br />respective acreages were totaled and partitioned by
<br />drainsge clll8S in Table 3-92.
<br />
<br />Table 8-9$. Number of acres available for ....gle and
<br />double C1'O'[11Iing by land class, lands
<br />sv.pplemental to Salt River Project.
<br />
<br /> Single Double Total
<br /> Cropped Cropped
<br /> (Acres) (Acres) (Acres)
<br />Land 1 10,160 4.627 14,787
<br />(Well Drained) 8,976
<br />Land 2 6.300 2,676
<br />(Moderately Drained)
<br />Land 3 1.980 616 2.596
<br />(poorly Drained)
<br />Total 18,440 7,919 26,359
<br />
<br />A list of the crops chosen for the model is shown
<br />in Table 3-93 along with the matrix of double cropping
<br />possibilities. As can be seen, lettuce and sorghum are
<br />very important in that they provide the most double
<br />cropping alternatives.
<br />
<br />Determination of base yields was made utilizing
<br />data information from the Salt River Project (Table
<br />3-86). These base figurea were used to establish crop
<br />yield declination curves under differing levels of water
<br />quality in accordance with the procedure in previous
<br />study areas. The model results demonstrated that
<br />little change can be expected in crop production and
<br />land use. Tabte 3-94 displays the optimal production
<br />and acreage amounts as estimated by the model.
<br />
<br />Since no significant change is observed over the
<br />TDS range considered applicable to this area, no
<br />
<br />.,
<br />
<br />Table 8-98. Selected crops and double cropping
<br />possibilities, lands sv.pplemental to Salt
<br />River Project.
<br />
<br />Double Cropping Possibilitiesa
<br />
<br />Crops
<br />
<br />Wheat Barley Lettuce Sorghum
<br />
<br />Alfalfa
<br />Cotton x x
<br />Barley
<br />Wheat
<br />Sorghum x x x x
<br />Lettuce x x x x
<br />Onion x x
<br />Sugar Beets
<br />
<br />RCraps under these columns are those assumed to lead
<br />in the double cropping rotation.
<br />
<br />attempt is made to estimate a damage function. In
<br />spite of this, Table 3-95 presenting water use, Table
<br />3-96 containing the dollar values of the objective
<br />functions, and Table 3-97 summarizing statistics
<br />applicable to the area are presented as supplementary
<br />information.
<br />
<br />Roosevelt Water CoIlservatloD DilItrIet
<br />
<br />The Roosevelt Water Conservation District
<br />(RWCD) is on the east side of and adjacent to the Salt
<br />River Valley Water Users Association District (Map
<br />3-11). It has a total irrigable area of 39,415 acres. In
<br />1973 this acreage consisted of 116 acres of urban and
<br />suburban residential, commercial, and industrial
<br />lands; 1,211 acres of farmsteads, roads, ditches, and
<br />drains; and 34,703 acres of cultivated cropland, of
<br />which 28,188 acres were irrigated (Annual Crop
<br />Production Reports, Roosevelt Water Conservation
<br />District).
<br />
<br />The water supply consists of 5.6 percent of the
<br />surface water diverted at Granite Reef Dam by the
<br />Salt River Project (SRP) and 55 active wells. Well
<br />water is pumped directly into the distribution system
<br />which consists of 141 miles of concrete lined canals and
<br />laterals (McClanahan, personal interview). The aver-
<br />age surface water supply from SRP has been
<br />approximately 50,000 ac ft per year2, and the average
<br />pumpage has been approximately 100,000 acre feet
<br />per year (Arizona Water Commission files). If we
<br />assume an allotment of 50,000 ac ft of Central Arizona
<br />Project (CAP) water (RWCD request was 75,000 ac
<br />ft), they would still have to continue pumping 50,000
<br />ac ft to meet their needs.
<br />
<br />No specific data on the salinity of the wells being
<br />pumped are available, however, an estimate can be
<br />made by averaging the published analyses made on
<br />wells within the district area (Tsble 3-98) (Babcock,
<br />1973). Increasing salinity of CAP water has the
<br />possibility of several different impacts to RWCD
<br />
<br />25.6 percent of 900,000 ae ft (9-year average now of the Salt
<br />and Verde Rivers). .' '{;lit
<br />
<br />183
<br />
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