Laserfiche WebLink
<br />~. <br /> <br />lG42 <br /> <br />----(Sediment-control-benefit)--- <br /> <br />, ' <br /> <br />~. <br /> <br />'. <br /> <br />,_.'_,u, ' <br /> <br />sediment is, therefore, ~4.34 which capitalized at 2-1/2 percent for <br />100 years equals ~159. <br /> <br />If gross direct and indirect benefits arA up,ed to determine the <br />value per acre-foc"t of res9!'7lJir capn.('.ity, the grof:s benefits drop from <br />$16, 643,300 wi'~h the 1..86 acre-f'Jet per acre pre','cnt sUFPly b <br />$14,300,000 wi';;h the 1064 acr8-1'eet per ",ore ':n thout existing private <br />reservoirs. T10e difference of ~2., 343,300 when c0,-rected for reservoir <br />efficiency and com,lUted en an acre-f00t basis becomes ii7 .62 p~r acre-foot. <br />This figure reduced by 'J.12 per acra-foot for ~peration and '!laintenance <br />beOOIDG8 $7.50 per acrc-f:Jc.t. Tho value pcr acre-foot of reservoir cnpn- <br />city deplet3d by sedime"t would theref8re be ;,7.50 capitalizEtd at 2-1/2 <br />percent for 100 years or 0275 per uc,re-foot. <br /> <br />The value of ~159 per ncre-fopt determined by using <br />was used, however, in this appendix for computing total <br />due_ to sediment retonti,on by__the potential reservoirs. <br /> <br />net benefits <br />annual benefits <br /> <br />. <br />,u The 'Corps of Enginecrs 'ha's estimo.ted that 2/3 of the sedimen't=-ent-cr- <br />i"'f': the J,ehn 1'1B.rtin "eservoir'~sdcpositGdin -I;he irrigc.tion p-o,oluIid" <br />1/3 is, deposited in the floodcoritr!>l space. Benefits fromwitnhoJjUng <br />sediment from entering tho ,flood control spaea, basad on raplacement <br />cost for this capacity, arc ostimated at ~43 per acre-foot by the Corps <br />of Engineers. Benefits from prolonging the usefulness of t)~ conser- <br />vation pool of John Martin Res'3rvoir are the same as those computed <br />for reservoirs devoted entir81y to irrigation. <br /> <br />The operation and maintenance costs of the irrigation systems are <br />incrcas'ed by th", aLlount of sedi",ent entering the canA.ls and laterals. <br />The cost of cleaning sediment fram laterals and canals is C8GO per acre- <br />foot (50t per cubic yard) ane, $160 per acre-foot (lOt per cubic yard), <br />respecti7ely. Any reduction in this CC,T would be of b6nefit to th8 <br />canal companies and to tho farmers. <br /> <br />On these bases the sediment retention in the potential reservoirs <br />would result in the a verage annual b6nefi ts shown in table 10. <br /> <br />. <br /> <br />.. <br /> <br />/ <br />18 <br />