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<br />. <br /> <br />, <br />Istudy area and arrived at a consensus average seepage loss of about 25 per-: <br />Icent of the diversion. Parshall (1922) measured seepage losses of 7.8 ft3/s <br />in a 9-mi reach (0.9 ft3/s per mil of Jackson Reservoir inlet canal and of <br />\19.3 ft3/s in a 19.7-mi reach (1 ft3/s per mil of the Empire Reservoir inlet. <br />.In 1967, D. R. Minges (U.S. Geological Survey, written commun., 1978) meas- <br />lured several of the reservoir inlet canals in the South Platte River basin <br />land calculated seepage losses ranging from 0.2 to 2.8 ft3/s per mi. Code <br />1(1945) reported canal losses in the nearby Prospect Valley of 0.6 ft3/s 'per <br />imi. ,Wors te 11 (1976) rev i ewed and summa r i zed 765 seepage tes ts made in the <br />iwestern United States and found that seepage rates normally ranged from <br />[0.1 ftld to 2 ftld, which for a typical canal width of 40 ft would range from <br />'0:2 to 5 ft3/s per mi. <br /> <br />Pond se~page was also computed using equation 13. Although there are no <br />,pond-seepage data for the project area, pond-seepage data from other areas <br />'were available and were the primary adjustment factors for the k2 parameter. <br />,Skinner (1963) computed changes in infiltration rates of about 0.25 ftld per <br />!ft for Olds Reservoir in Prospect Valley. Taylor (1975) computed values from <br />:0.04 to 2 ftld per ft in several ponds near Fountain, Colo. Emmons (1977) <br />:computed average rates of change of 0.7 ftld per ft, 4 ftld per ft, and <br />14 ftld per ft at three sites in El Paso County, Colo. Pri 11 (1977) computed <br />'values ranging from 0.7 to 2.2 ftld per ft for a pond in western Kansas. <br />, <br />, <br /> <br />, <br /> <br />I <br />i <br /> <br />j <br /> <br />I 'An impqrtant aspect of the proposed project is the wildlife-environment <br />:enhancement due to the ponds. Estimates of the diversions to ponds and their <br />,size and number are necessary parameters for assessing that part of the proj- <br />'ect. Because no site-specific engineering has been done, typical pond geome- <br />'tries were computed and it was assumed that ponds would be placed uniformly <br />~long canals located in the sand hills. <br /> <br />I Several model-simulation runs were made to evaluate the effects of <br />'various pond diversions. Each simulation was made over several months with a <br />~articular inflow diversion until the ponds reached a steady-state condition. <br />An example of the results of one such simulation is shown in table 3. After <br />making several of these simulations, figure 8 was drawn to illustrate the di- <br />:version into a pond necessary to maintain it at a certain surface area. <br />:Steady-state seepage is nearly equal to the inflow, with the evaporation be- <br />'ing much smaller than the seepage. A problem with the transient analysis that <br />, <br />,needs to be resolved for any additional studies involves the oscillations in <br />'all values other than inflow in table 3. Although not considered critical <br />,for this analysis, the use of smaller time steps or some predictor-corrector <br />:technique would result in oscillations with reduced magnitudes--the ideal be- <br />~ing no oscillations. <br /> <br />Average Pond Conditions <br /> <br />I <br />L <br /> <br />J~ <br /> <br />I <br /> <br />!....---,-- <br />I <br /> <br />-~_._---_.-- ----~--------------_. ------ - --- <br /> <br />~- <br />.~ <br />