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<br />and implement demonstration projects to address improved <br />N <br />w::.. irrigation practices through better timing of water delivery <br />~ <br />tn and switching to sprinkler irrigation. <br /> <br />Forum Activities <br /> <br />Salt-Flow Relationships <br /> <br />During the final stages of <br /> <br />preparation of the 1978 revision to the salinity standards, <br />it became apparent that the rate of projected salinity <br />increases was overestimated when compared to recent histori- <br />cal salinity trends. Salinity levels since 1972 have been <br />declining. A part of the decrease is now considered to be <br />due in part to an apparent change in the flow versus salt <br />load relationship which occurred in the period after 1968 <br />with the filling and operation of the major reservoirs of <br />the Upper Basin, The reason for this salt load reduction is <br />not fully understood. A study to develop flow versus salt <br />load relationships reflecting present conditions of develop- <br />ment was initiated, Mass balance, multiple regression, and <br /> <br />statistical methods are being used to analyze model inputs <br /> <br /> <br />under base conditions over which future changes will be <br /> <br /> <br />superimposed to estimate projected future salinities for the <br /> <br /> <br />1981 standards revision. It appears that a significant reduc- <br /> <br /> <br />tion in salt load has occurred in the Colorado River above <br /> <br />Cisco, Utah, beginning in about 1969. Analysis of the data <br />for the river reach, Lees Ferry to Grand Canyon, also indi- <br />cates a reduction in salt load beginning about 1955 and <br />again after the closure of Glen Canyon Dam. Although the <br /> <br />24 <br />