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<br />utilization of saline flows, are being implemented by
<br />State or private entities. Other techniques requiring
<br />more detailed studies include salt removal at points of
<br />diversion to use, and such long-range concepts as
<br />dilution through augmentation by weather
<br />modification, desalting sea water, and developing
<br />geothermal resources.
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<br />
<br />PREFACE
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<br />This status report was prepared by Bureau of
<br />Reclamation staff personnel as the biennial program
<br />appraisal referred to in the February 1972 report of
<br />the Bureau of Reclamation entitled "Colorado River
<br />Water Quality Improvement Program" (CRWQIP).
<br />That report forme'd the basis for unanimous
<br />recommendations developed by Federal and State
<br />conferees at the Seventh Session of the Environmental
<br />Protection Agency's 1972 conference on "Matters
<br />Relating to the Pollution of the Interstate Waters of
<br />the Colorado River and Its Tributaries." The
<br />Reclamation report stated that "Appraisal and program
<br />progress and direction will be made at intervals of 2
<br />years." The factors to be considered include: (1) kinds
<br />of physical control works needed, (2) economic
<br />evaluation of possible control works, (3) public
<br />acceptance and commitment to control, (4) potential
<br />impacts of evolving technology, and (5) relationships
<br />within the basinwide management plan. Moreover, the
<br />recommendations of the conference provided that the
<br />Bureau of Reclamation report on general program
<br />progress annually to the conferees and other interested
<br />State agencies.
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<br />The results displayed in this status report are based on
<br />investigations and research conducted during the past 2
<br />years. Although these studies are largely rooted in prior
<br />efforts of the Environmental Protection Agency, the
<br />Colorado River Board of California, the U.S.
<br />Geological Survey, and the Bureau of Reclamation,
<br />they do not as yet unfold a comprehensive basinwide
<br />control plan.
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<br />These prior studies and the recommendations of the
<br />conference were used to structure the program.
<br />Consequently, emphasis was placed on determining the
<br />effects of salinity levels and on methods of controlling
<br />salinity from irrigation, point, and diffuse sources. As
<br />the studies progressed, it became evident that within
<br />this array, -prime considerations should be given to
<br />non structural or minimal land treatment approaches.
<br />Beginning in FY 1974, increased emphasis was placed
<br />upon such measures as improving irrigation efficiencies,
<br />improving management of the river and water
<br />conveyance systems, utilizing saline flows, managing
<br />Federal lands for salinity control, reformulating the
<br />plans for water resource developments to minimize salt
<br />loading, examining salt precipitation phenomena in
<br />large reservoirs, and reducing evapotranspiration
<br />through treatment and management of vegetation.
<br />Some of the measures, such as improving irrigation
<br />efficiencies, are being conducted directly within the
<br />CRWQIP, while others, such as the research on salt
<br />precipitation phenomena in reservoirs and the
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<br />Salinity control is viewed in these investigations as a
<br />related facet of an evolving comprehensive plan for
<br />managing the water resources of the Colorado River
<br />Basin. No single measure can achieve the goals
<br />established by the 1972 Enforcement Conference and
<br />the seven basin states of 11* * * maintaining salinity at
<br />or below present levels in the lower main stem:' The
<br />CRWQIP has been evaluating and will continue to
<br />evaluate alternative ways to meet the salinity problem.
<br />Whether or not specific solutions can be recommended
<br />depends, in part, on the results of the economic,
<br />institutional, and legal studies. Moreover, there has
<br />been no commitment by the Federal Government to
<br />any specific solutions that may be identified during the
<br />evaluations.
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<br />Salinity control, particularly as applied to a large river
<br />basin, is a novel undertaking. Many physical, social,
<br />economic, and legal complexities are involved.
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<br />In the physical area, the relative proportion of salinity
<br />attributable to various sources such as natural springs,
<br />natural solute erosion, irrigation, evaporation,
<br />out-of-basin export, and municipal and industrial uses
<br />have been identified only in a preliminary manner. For
<br />example, all irrigation projects are assumed to
<br />participate in salt loading the river system. Recent
<br />studies, however, suggest that irrigation under some
<br />conditions may actually remove salts from the system.
<br />Also, various portions of the basin are remote.
<br />Data-gathering in these areas has been difficult and the
<br />historic data base has not always been adequate to
<br />provide reliable assessments of the impact of various
<br />water uses. The program is therefore developing a
<br />reliable data base.
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<br />Complex social questions arise with respect to value
<br />judgments involving salinity goals, environmental
<br />impacts of salinity control, accounting for the water
<br />losses that would be attributable to salinity control,
<br />and cost sharing. The latter is particularly important
<br />since most of the entities being impacted by the rising
<br />salinity levels are located in or divert from the lower
<br />portions of the basin, while most of the salinity
<br />originates in the upper portions of the basin.
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