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<br />. <br />. ..:.-:. <br /> <br />~ <br /> <br />'.. <br /> <br />The hydrosalinity analysis (Reclamation, 1982) for the FR/FES predicted the 1984 Plan <br />would reduce salt loading about 140,500 tons per year. Lining of the east side canals and <br />laterals accounted for 66,500 tons of this reduction. The report does not present separate <br />infonnation for lining the laterals vs. canals. Subsequent reevaluation (Reclamation, 1994) <br />of the analysis shows an increase in estimates to almost 95,000 tons, with 63,880 tons <br />attributed to lining the laterals and 31,000 to the canals. <br /> <br />Cost effectiveness for the 1984 Plan was reported as the cost of decreasing salinity <br />concentrations at the Imperial Dam in the lower basin. It was not calculated separately for <br />laterals vs. canals. The FR Supplement reports it as the annual cost of removing 1 ton of salt <br />from the river ($/ton/year). Using updated annualized costs for lining only the laterals with <br />concrete and replacing habitat (i.e., about $7,640,(00) and the hydrosalinity analysis results <br />of the FR Supplement (63,880 tons) shows the annual cost of lining only the laterals and <br />replacing habitat would have been about $120Iton. Similarly, annual cost of lining the canals <br />with concrete and replacing habitat would have been about $218/ton/year. <br /> <br />East Side Laterals Proiect <br /> <br />The recommended project incoiporates several conclusions from studies of the 1984 Plan: <br /> <br />I. The Winter Water Replacement Program reduces annual salt loading about 41,380 <br />tons (a decrease from the 1984 Plan estimate of 74,000 tons). Another 94,880 tons could be <br />eliminated by lining and/or piping the canal and lateral systems (an increase from 66,500 <br />predicted for the 1984 Plan). Of this, about 63,880 tons would be from piping the laterals. <br /> <br />2. It would cost less to place lateral systems and low-capacity canal segments in pipe <br />compared to lining open ditches with concrete. For the canals, additional savings would <br />result from lining them with plastic sheets (pVC or membrane), using current methods. <br /> <br />3. Significant savings (up to 40 percent) would be realized if the UVWUA would <br />install pipelines under a cooperative agreement with Reclamation instead of using a <br />traditional construction contract. <br /> <br />4. An updated inventory of seepage-dependent wetlands is needed to better identify <br />effects on wetlands. The replacement program needs to be revised to better meet current <br />policies for wetland protection, and address socio-economic concerns for the program. <br /> <br />Updated cost saving measures still showed lining canals would not be cost effective (about <br />$140/ton in January 1994 prices, not including habitat replacement costs). Therefore, lining <br />the canals was eliminated from further study, and remains a deferred portion of the 1984 <br />Plan. The FR Supplement (Reclamation, 1994) documents detailed recommendations for <br />piping laterals and small canal segments. <br /> <br />6 <br />