Laserfiche WebLink
<br />. <br /> <br />Table 2-4 <br />Salinity Control Requirements <br /> <br />. <br /> <br />o <br /><::1 <br />W <br />N <br /> <br />1998 Salinity Control Requirements <br />Requirements 1,105,000 tons/year <br />11easuresinPlace 721,000 tons/year <br />Shortfall 384 000 tons/vear <br />2015 Salinity Control Requirements , <br />Requirements 1,477,000 tons/year <br />11easures in Place throul!;h 1998 721,000 tons/year <br />Plan of Implementation Target 756,000tons/vear <br /> <br />Future salinity concentrations will depend not only upon human activities but upon natural <br />phenomena, such as runoff conditions, natural evapotranspiration, and dissolution and mixing within <br />the major storage reservoirs, Even with full implementation of the Colorado River Basin Salinity <br />Control Program's current Plan of Implementation which offsets the human impacts since 1972 and <br />through 2015, the actual concentrations at the three numeric criteria stations (and elsewhere in the <br />Basin) will continue to fluctuate in response to hydrologic conditions, <br /> <br />, <br /> <br />. <br /> <br />Exceedance Evaluation <br /> <br />A statistical analysis was performed for the 1996 Review and reproduced in this Review in <br />order to determine the effecttveness of the program in maintaining the numeric criteria, The analysis <br />evaluated four conditions of various levels of salinity control ranging from no controls to <br />implementing the Plan, Data were developed which indicate the frequency of occurrence of various <br />mean annual salinity concentrations, Provided the salinity control measures in the Plan of <br />Implementation are in place, the mean arulUal flow-weighted salinity concentrations at the three <br />lower mainstem stations would be at or below the numeric criteria, with Hoover Dam being the <br />controlling station, This statistical analysis can be found in Appendix C of the 1996 Review, <br /> <br />Impacts of Hydrology <br /> <br />Beyond the exceedance percentages shown in Appendix C ofthe 1996 Review which show <br />how often various salinity levels should be attained, it is important to understand that annual salinity <br />concentr!ltions may remain depressed or elevated for a period oftime, The historical plot of salinity <br />at Imperial Dam shown in Figure 2-2 earlier in this Review effectively demonstrates this, <br /> <br />. <br /> <br />2.10 <br />