<br />iGG\
<br />
<br />Recovery from the 1977 Dry Year
<br />
<br />The Board's 1977 Annual Report
<br />noted that the virgin flow of the Colo-
<br />rado River at Lee Ferry for water year
<br />1976-77 set a new record for histori-
<br />cal low flows and created severe de-
<br />mands on Colorado River system
<br />water supplies. The above average
<br />runoff during the 1977-78 water year
<br />increased Basin reservoir storage by
<br />about 2.6 million acre-feet. Prelimi-
<br />nary estimates of 1978-79 runoff,
<br />based upon Upper Colorado River Ba-
<br />sin snowpack conditions as of January
<br />1, 1979, point to another year of
<br />above-average runoff, This, combined
<br />with unusually high streamflows dur-
<br />ing December 1978 on the Bill Wil-
<br />liams and Gila Rivers in the Lower
<br />Basin, indicate a full recovery from
<br />the effects of the 1977 dry year.
<br />
<br />Potential Future Surplus Flows
<br />
<br />The Board's 1977 Annual Report
<br />described joint Bureau of Reclama-
<br />tion-Corps of Engineers studies of al-
<br />ternative reservoir operating strategies
<br />during the years prior to completion
<br />of the Central Arizona Project when
<br />surplus flows are imminent and reser-
<br />voir spills are likely to occur. These
<br />studies continued during 1978 but,
<br />due to a lack of urgency resulting
<br />from the drawdown of about 5.6 mil-
<br />lion acre-feet of water from storage in
<br />1977, no meetings were held on their
<br />findings.
<br />
<br />Program for Banking Water
<br />in Lake Mead
<br />
<br />During 1978, meetings were held
<br />between the California State Depart-
<br />ment of Water Resources, The Metro-
<br />politan Water District of Southern
<br />California, and the Board to discuss a
<br />concept for banking, or storing, water
<br />in Lake Mead. Briefly, the concept in-
<br />volves Metropolitan increasing its
<br />deliveries from the State during years
<br />of good supply for the State Water
<br />Project, taking less than its annual
<br />Colorado River apportionment, and
<br />
<br />having a like amount credited to its
<br />account in Lake Mead, In years of
<br />low water supply from the State Wa-
<br />ter Project, in addition to its annual
<br />apportionment, Metropolitan would
<br />divert water credited to its account in
<br />Lake Mead,
<br />The proposal was also discussed
<br />with representatives of the other Cali-
<br />fornia Colorado River water contrac-
<br />tors and the States of Nevada and
<br />Arizona and it was agreed to com-
<br />mence studies on this concept.
<br />
<br />Water Quality
<br />
<br />Colorado River Salinity Standa;ds
<br />
<br />The Colorado River Basin states in
<br />1975 adopted numerical standards for
<br />salinity in the Colorado River. Under
<br />the provisions of Section 303 (c) ( 1) of
<br />Public Law 92-500, the states are to
<br />review these standards at least once
<br />during each three-year period and, as
<br />appropriate, to modify them.
<br />The seven-state Colorado River Ba-
<br />sin Salinity Control Forum, through its
<br />permanent Work Group, which is
<br />chaired by the Board's Chief Engineer,
<br />conducted engineering studies of fac-
<br />tors affecting future salinity in the Col-
<br />orado River and prepared a draft of
<br />the report entitled "1978 Revision,
<br />Water Quality Standards for Salinity
<br />Including Numeric Criteria and Plan of
<br />Implementation for Salinity Control,
<br />Colorado River System", The report
<br />constitutes the first triennial revision of
<br />the standards and plan of implementa-
<br />tion.
<br />Following approval of the report by
<br />the Forum on August 29, two regional
<br />public hearings were held on Novem-
<br />ber 14 and 16, in Las Vegas, Nevada,
<br />and Grand Junction, Colorado. A sup-
<br />plement to the report was then pre-
<br />pared containing a summary and anal-
<br />ysis of the comments received during
<br />and after the meeting and appropriate
<br />modifications to the report. On De-
<br />cember 18, the Forum approved the
<br />supplement and directed that the re-
<br />port and supplement be sent to the
<br />individual states for adoption.
<br />The Forum found no reason to rec-
<br />ommend changes in the numeric sa-
<br />
<br />8
<br />
<br />linity criteria adopted in 1975 at the
<br />lower mainstem stations, which are:
<br />
<br />Salinity in mgj I
<br />Below Hoover Dam....,.....,...., 723
<br />Below Parker Dam.,.......,..,...., 747
<br />Imperial Dam ..,....,..,............... 879
<br />
<br />Salinities at each of the stations
<br />have been decreasing almost consist-
<br />ently since 1972, In 1978, the flow-
<br />weighted salinity at Imperial Dam, for
<br />example, was 67 mgll below the nu-
<br />meric criteria. The current and pro-
<br />jected rate of basin-wide water
<br />development is slower than estimated
<br />in the 1975 report. Although progress
<br />on the salinity control program also
<br />has been slower than anticipated,
<br />there is no reason to believe that the
<br />numeric criteria will be exceeded dur-
<br />ing the next three-year revision peri-
<br />od.
<br />
<br />Colorado River Basin Salinity
<br />Control Program
<br />
<br />The Bureau of Reclamation con-
<br />tinued its efforts on Colorado River
<br />salinity control projects and the Colo-
<br />rado River Water Quality Improve-
<br />ment Program in accordance with the
<br />Colorado River Basin Salinity Control
<br />Act of 1974, P.L. 93-320. The Soil
<br />Conservation Service continued its ac-
<br />tive role in salinity control through its
<br />on-farm water management program.
<br />A draft contract for the operation
<br />and maintenance of the Grand Valley
<br />Unit by local agencies was completed
<br />by the Bureau. Execution of the con-
<br />tract, which includes economic penal-
<br />ties for excessive water diversions, is
<br />required before construction can be-
<br />gin on this unit. The Soil Conservation
<br />Service continued its activities in the
<br />Valley and issued its final report de-
<br />scribing its proposed on-farm program
<br />for salinity control. Current plans call
<br />for completion of the salinity control
<br />programs of the Bureau of Reclama-
<br />tion and Soil Conservation Service in
<br />1990 and an estimated reduction of
<br />the salts picked up in the Grand Val-
<br />ley by 410,000 tons annually.
<br />The Bureau completed the Environ-
<br />mental Impact Statement and the
<br />Definite Pian Report for the Paradox
<br />Valley Unit. Construction of a tempo-
<br />rary brine conveyance pipeline and
<br />
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