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<br />
<br />
<br />Recommended Plan
<br />
<br />Plan 7 is recommended for implementation. This plan was selected
<br />after considering local reaction from reviewing the eight candidate plans at
<br />public meetings with farmers and ranchers in the valley and after considering
<br />comments on the draft report received from officials of local, state and federal
<br />agencies and with other interested groups. Major factors influencing the
<br />selection include the desires of local landowners and operators, cost effective
<br />salinity reduction, overall implementation cost, and program administration.
<br />Program implementation will extend over a ten year period. Effectiveness of
<br />the program should be monitored and the data evaluated at three year intervals
<br />to determine whether the improvements are achieving the expected degree of
<br />salinity reduction.
<br />
<br />Plan Description
<br />
<br />Irrigation water management, consisting of close prec1s1on in control-
<br />ling the time of set and the flow rate per furrow during each irrigation,
<br />supplemented by installing water measuring devices and leveling of irrigated
<br />fields comprise the minimal level of improvement needed in Watersheds 2, 4, 5,
<br />6, 10, 12, 13, 14, 15, 16, 18, 21, 23, 24, 25, and 26 (see Table IV-2). Onfarm
<br />ditch lining in addition to the minimum level of improvement is cost effective
<br />and will be included in watersheds 4 and 21. Intensive treatment, consisting
<br />of irrigation water management and the practices listed in Table IV-2, have
<br />been identified as cost effective and needed in watersheds 1, 3, 7, 8, 9, 11,
<br />17, 19, 20, and 22 to achieve objectives of the salinity control program.
<br />Improvement of off-farm laterals in watersheds 1, 3, and 9 not needed for
<br />proper operation of onfarm system improvements is also included. The cost for
<br />implementing the recommended plan, together with the expected reduction in
<br />salt loading, are based on strict adherence to implementing those improvements
<br />listed in Table IV-2 only in the respective watershed areas.
<br />
<br />When completed implementation of the recommended plan will result in a 335,000
<br />ton per year reduction in salt loading, about a 52 percent reduction in the
<br />640,000 ton salt load delivered annually to the Colorado River from irrigation
<br />sources in the Lower Gunnison Basin.
<br />
<br />The estimated total installation cost is $169,400,000. Of this amount $110,911,000
<br />is the construction cost for onfarm improvements (including $120,000 for voluntary
<br />implementation of mitigation practices), $15,269,000 is the construction cost
<br />for 104 miles of off-farm lateral improvements, $25,740,000 is the cost of
<br />administrative and technical assistance, and an additional $17,600,000 is
<br />needed if full mitigation for the loss of habitat values is required. After
<br />the recommended plan is fully implemented the annual local cost for operation,
<br />maintenance and replacement is estimated to be $800,000. The average annual
<br />cost including operation, maintenance and replacement is $22,460,000, expressed
<br />in present value terms. The present value of benefits is $31,490,000 giving
<br />average annual net benefits of $9,030,000.
<br />
<br />IV-20
<br />
<br />
<br />Implementation of this plan will impact on 3,800 acres or 10 percent of the
<br />wetlands in the Lower Gunnison Basin. Full mitigation for the impacted habitat,
<br />estimated to cost $17,600,000, would require upgrading the habitat value on '
<br />8,900 acres of wetlands elsewhere in the valley not otherwise disturbed by
<br />implementing this plan.
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