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<br />Basin Water Quality Control Project was established as a result of the
<br />Conference, producing the first extensive field investigations of salin-
<br />ity effects.
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<br />The findings and data generated by this Project were based on a
<br />methodology that had been worked out and published by Pincock.l This
<br />methodology was based on the salt tolerance curves of Bernstein2 and a
<br />crop budgeting approach. Pincock's initial study concerned only the
<br />Wellton-Mohawk Irrigation District in Yuma County, Arizona. Pincock at
<br />that time concluded "A change in water quality of the magnitude studied
<br />[800 ppm in 1960 to a projected 1,233 ppm in 2010] did not indicate an
<br />adjusted cropping pattern. . , . Salinity damages were negligible in
<br />1980 [at 920 ppm] . , . By 2010, projected damages were $854,679 gross
<br />or $464,614 net. . ." Insofar as those results could be generalized to
<br />other agricultural areas, the potential damages did not appear extensive.
<br />
<br />The first major report of the Colorado River Basin Water Quality
<br />Control Project was the multivolume study The Mineral Quality Problem in
<br />the Colorado River Basin, published by the U.S. Environmental Protection
<br />Agency (Regions VIII and IX) in 1971. This expanded study geographically
<br />covered the Lower Main Stem, Southern California, and the Gila area. It
<br />also considered indirect as well as direct income losses for agriculture,
<br />industry, and municipal (residential) uses. A summary of their projected
<br />incremental losses is given in Table III-I. These results established the
<br />serious potential of the salinity problem in the Lower Basin.
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<br />Significant advances in the methodology of salinity damage mea-
<br />surement were made by Sun, Moore, and Snyder between 1972 and 1974.3
<br />Using Bernstein's experimental results, linear programming activities
<br />were constructed for 108 ways of growing each major crop of the Imperial
<br />Valley, using variations in soil types, irrigation treatments, water
<br />quality levels, and leaching fractions. Farm models were constructed
<br />
<br />1M, Glade Pincock, "Assessing Impacts of Declining Water Quality
<br />on Gross Value Output of Agriculture, A Case Study," Water Resources Re-
<br />search, Vol,S, No.1, February 1969.
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<br />2Leon Bernstein, Salt Tolerance of Plants, U.S, Department of
<br />Agriculture Information Bulletin 283, December 1964.
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<br />3p.C. Sun, "An Economic Analysis of the Effects of Quality and
<br />Quantity of Irrigation Water on Agricultural Production in Imperial Val-
<br />ley, California," Ph.D. dissertation, Department of Agricultural Econo-
<br />mics, University of California, Davis, California, 1972; and C.V, Moore,
<br />J.H. Snyder, and Peter Sun, "Effects of Colorado River Water Quality and
<br />Supply on Irrigated Agriculture," Water Resources Research, Vol. 10,
<br />No.2, April 1974,
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<br />111-3
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