Laserfiche WebLink
<br />(~ ,:'0.3~ <br /> <br />During 1990 storage in most of the major reservoirs on the <br />Colorado River declined and only flows required to meet downstream <br />demands were released. The reduced flows in 1988 thru 1991 have <br />resulted in an increase in salinity concentrations in the major <br />reservoirs. <br /> <br />. <br /> <br />HISTORICAL USES <br /> <br />Estimated historical Lower Basin mainstream and Upper Basin <br />uses for calendar years 1975 through 1990 are shown in Table 2. <br /> <br />SALINITY CONCENTRATION AT MONITORING STATIONS <br /> <br />Salinity concentrations for the years 1973-1990 at the three <br />stations at which numeric criteria have been set: below Hoover Dam, <br />below Parker Dam, and at Imperial Dam, are shown in Table 3. These <br />concentrations are all less than the numeric criteria. <br /> <br />TABLE 3 <br />FLOW-WEIGHTED AVERAGE ANNUAL SALINITY CONCENTRATIONS <br />AT SELECTED STATIONS <br />(Total Dissolved Solids in mg/l*) <br /> <br />~ <br /> <br />. <br /> <br />Calendar <br />Year <br />Numeric <br />criteria <br />1973 <br />1974 <br />1975 <br />1976 <br />1977 <br />1978 <br />1979 <br />1980 <br />1981 <br />1982 <br />1983 <br />1984 <br />1985 <br />1986 <br />1987 <br />1988 <br />1989 <br />1990 <br /> <br />Below Hoover <br />Dam <br /> <br />Below Parker <br />Dam <br /> <br />At Imperial <br />Dam <br /> <br />723 <br />675 <br />681 <br />680 <br />674 <br />665 <br />678 <br />688 <br />691 <br />681 <br />679 <br />658 <br />598 <br />556 <br />517 <br />519 <br />529 <br />550 <br />578** <br /> <br />879 <br />843 <br />834 <br />829 <br />822 <br />819 <br />812 <br />802 <br />760 <br />821 <br />827 <br />727 <br />675 <br />615 <br />577 <br />612 <br />648 <br />680 <br />721** <br /> <br />747 <br />709 <br />702 <br />702 <br />690 <br />687 <br />688 <br />701 <br />712 <br />716 <br />713 <br />678 <br />611 <br />561 <br />535 <br />538 <br />540 <br />558 <br />629** <br /> <br />*Determined cooperatively by the U.S. Geological Survey <br />(USGS) and Reclamation. Published in "Quality of Water <br />- Colorado River Basin," Progress Report No. 15, January <br />1991. Some of these values have been revised from <br />previous years. <br /> <br />. <br /> <br />**provisional records. <br /> <br />4 <br />