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<br />Diversion and salinity <br /> <br />All of the flow of the La Plata river will be diverted to <br />the Southern Ute Reservoir. Return flows from the' project <br />land (988 acres and l,874 acres) receiving water will be <br />diverted back into the Southern Ute Reservoir. The flows <br />from the Dryside Canal would also return to the Southern <br />Ute Reservoir. The reservoir would be maintained at one-half <br />capacity during average runoff years. <br /> <br />Nutrient loads from irrigated lands and the Ridges Basin <br />Reservoir are not quantifiable, leaving some doubt as to the <br />trophic state of the Southern Ute Reservoir due to nutrient <br />loading according to the EIS. <br /> <br />Because of the diversion of 154,000 acre-feet of water out <br />of the Colorado river system, the project will increase <br />salinity levels at the Imperial Dam by 17.9 mg/l (l.7t). <br />There would ~e a 300% increase in the average flow-weighted <br />salinity of the La Plata River downstream of the Southern <br />Ute Diversion Dam which would be caused ~y the project <br />return flows and reuse of irrigation water. It i. estimated <br />that the Animas River would have a lot increase in .alinity. <br /> <br />It is estimated that the Animas La Plata project would <br />increase salinity levels in the Colorado river at Imperial <br />dam by 18.6 mg/L as a result of the concentratinq effect of <br />stream depletions and reduce salinity levels by 0.7 mg/L as <br />a result of the salt reduction from return flow. Irriqation <br />water would leach the remaining salt. from upper lands and <br />deposit them in the lower class six shale bottoms where <br />drainage is restricted. <br /> <br />The average annual increase, based on the 100-year average <br />would total 17.9 mq/l as measured at Imp.rial dam, about 1.7 <br />percent above current levels. Studies by the USSR conclude <br />that increasinq .alinity causes both direct and indirect <br />economic lo.se. in the Colorado River Ba.in estimated at <br />$343,000 annually for each increa.e of 1 mg/l at Imperial <br />Dam tor a total of $6 million. annually from building the <br />Animas La Plata Project. <br /> <br />In agriculture, losses come from decreased crop yields, <br />increased management costs, and the application of various <br />adaptive practices. In the municipal and indu.trial areas, <br />the 10.... ari.e primarilY from increased water treatment <br />co.ts, accelerated pipe corro.ion and appliance w.ar, <br />increa..d u.e of .oap and detergent., and decrea.ed <br />palatability of drinking water. <br /> <br />;, <br /> <br />:;- <br /> <br />" <br />, <br />, <br /> <br />~: <br /> <br />;.-., <br /> <br />;'. <br /> <br />I <br /> <br />, <br />t <br /> <br />":. <br />". <br /> <br />i~' <br /> <br />~'; <br />" <br /> <br />" <br /> <br />ff <br /> <br />,':;< <br />~ <br />:~ <br /> <br />34 <br />