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<br />~",.... <br /> <br />I <br /> <br /> <br />... CHAPTEf/2. WATER RESOURCE INVENTORY <br />! <br />Efficiencies I <br />i <br /> <br />On~ valuable aspect of the water budget is that rtprovides a m~ans to calculate efficiencies. Estimating <br />efficiencies helps identify potential areas for irrigation improvemehts. As displayed in Table 2-4 and Table <br />2-5, the following efficiencies were estimated: i <br /> <br />1. Overall efficiency = Crop requirements / Total diversio~s <br />2. Delivery efficiency = Farm deliveries / Total diversions. <br />3. Farm efficiency = Crop requirements / Farm deliveries <br /> <br />Overall efficiency of the Fire Mountain Canal system was estimated to be between 36 and 38 percent. <br />This indicates that crops are using 36 percent of headgate div,ersions. The remaining water (64%) is <br />being lost through delivery and on-farm inefficiencies. USBORoriginally estimated a 27 percent overall <br />efficiency for Fire Mountain Canal (USBOR 1957). Therefore, overall efficiency is greater than originally <br />estimated. <br /> <br />Delivery Efficiency was estimated to be approximately 80 percent. This indicates 20 percent of the <br />headgate diversions are lost during delivery in the Fire Mountain Canal. USBOR originally estimated a <br />30 percent delivery loss for length of the canal (USBOR 1957). Therefore, water delivery is currently <br />more efficient than originally estimated. <br /> <br />Farm efficiency was estimated to be approximately 46 percen~. This means 46 percent of the water <br />delivered to farms is actually used by crops. USBOR originally estimated a farm efficiency of 57 percent <br />(USBOR 1957). Therefore, current estimates do not meet original estimates. <br /> <br />Water Budget Results <br /> <br />Upon review of the water budget, the following observations are made: <br /> <br />1. Overall, the Fire Mountain Canal is doing a relatively good job matching diversions with crop <br />demands (Figures 2-3 and 2-4). Small amounts of excess water is diverted in the early and <br />. .Iate irrigation months; however, inadequate water is being diverted during the peak demand <br />months. There is the potential to increase diversions during peak demand (June, July) and <br />decrease diversions during May and August. Excess water in the early months can just be a <br />result of flushing flows used during the turn-on of the canal. <br /> <br />2. While Fire Mountain Canal is not a typical demand-type irrigation system, water is being <br />supplied to match crop demand. <br /> <br />3. Evaporation is a minor contributor to delivery losses. ; <br />I <br /> <br />4. Delivery losses are low for an earthen ditch canal: (20%). Based on discussions with the <br />Natural Resources Conservation Service {NRCS),e~rthen ditch canals in our area can lose up <br />to 40 percent of water diverted (Boyce 2000). ! <br /> <br />5. On-farm efficiencies are approaching 50 percent, which is relatively good for surface irrigation <br />through gated-pipe systems. Typically, surface irriga~ion in our region, by the use of furrows or <br />corrugations, achieves a maximum efficiency of 50 percent. <br /> <br />6. The greatest efficiency improvements would be qbtained by upgrading on-farm irrigation <br />systems to more efficient methods such as surge or sprinkler irrigation systems. <br /> <br />2-15 <br /> <br />-1- <br /> <br />II <br />~) <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />el <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />(~.. <br />~I <br />I <br />