Laserfiche WebLink
<br />002506 <br />o Figure 2 presents seepage (percent of headgate diversion) versus headgate <br />diversion (cfs), As presented, the percent of headgate diversions seeping decreases <br />as the discharge increases, Note the data represents only a portion of the canals' <br />length. Other anomalies presented in this figure, particularly in the USBR data, <br />demonstrate the importance of other variables associated with ditch seepage and <br />potential problems associated with one time measurements. <br /> <br />o <br /> <br />Figure 3 combines the results of Figures 1 and 2 by presenting canal loss (cfs/mile) <br />versus headgate diversion (cts), Note the curve which exhibits the greatest loss per <br />mile per diversion includes Fort Lyon and Colorado Canal which are located <br />upgradient from other canals in the system and may be expected to receive <br />relatively little subsurface inflow to compensate for canal seepage, The lower curve <br />exhibits less loss per mile per diversion and is associated with data on the Amity <br />Canal which is bounded by the Fort Lyon over approximately 50 percent of its length <br />and may be expected to receive more subsurface inflow to compensate for canal <br />seepage, The scatter of data presented in Figure 3 again demonstrates the <br />importance of other variables associated with ditch loss, . <br /> <br />) I <br />Ii <br />; i <br />I <br />, <br />; <br />'; <br />I <br /> <br />1 <br /> <br />o Each ditch in the Arkansas can be fit to a curve similar to those presented in Figure 3 <br />of the form q = a Qb; where q = average monthly ditch loss (cfs/mi) Q = average <br />monthly ditch diversion (cfs) and a and b are coefficients, the coefficients a and b <br />can be estimated to approximate 'the averages reported by court decrees, <br />engineering studies and company interviews, This approach wiil allow seepage to <br />vary over time for each canal based on discharge and length, In addition, by <br />calibrating to available reported data the unique properties of each ditch such as <br />subsurface inflows and geometry will be incorporated, <br /> <br />The following conclusions and observations were deveioped after reviewing lateral loss data <br />presented in Table 3 and a field inventory for Water District 67 ditches prepared by Bill Howland, <br /> <br />o Available estimates ranging from 5 to 10 percent appear to be based on engineering <br />judgement since no field measurements were identified, <br /> <br />3 <br />