C153604 Feasibility Study - Laserfiche WebLink

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. . Table 8), Excluded from Table 8 are reservoir losses, which are reflected in the reservoir storage content, not releases. Reservoir evaporation losses are estimated to be on the order of 3.900 acre- feet per year, The annual reservoir seepage loss is estimated to be about 700 acre-feet. based on measured and estimated seepage discharges through the dam embankment and foundation, The reservoir evaporation and seepage calculations are included in Appendix G. Total reservoir losses are estimated to be 4,600 acre-feet per year, As a comparison. the State Engineer's inflow and release records (Tables F2 and F4) show a total seepage and evaporation loss of about 3,900 acre- feet per year (1980-1990), Overall, ditch and reservoir losses are estimated to be about 13,000 acre- feet per year, . . . It is readily apparent that any storage restrictions by the State Engineer against Julesburg Reservoir will have a major impact on the water available for irrigation, I n general terms, for each foot of depth that the reservoir storage 15 restricted, there would be a reduction of about 1,470 acre- feet in storage capacity, Currently, the State Engineer's long-term storage restriction on Julesburg Reservoir is at gage height 23,0, with no guarantee that the restricted water level will not be lowered further, The current restriction equates to about 3,700 acre-feet of lost storage, assuming that the District would normally operate the reservoir at a maximum gage height of 25,5, Refer to Figure 3 for the reservoir elevation-area-capacity relation, . . Based on examination of the storage release records in Appendix F, Table F4, the reservoir typically releases an average of about 14,000 acre-feet each year for irrigation. The maximum reservoir storage release during the study period was nearly 20,000 acre-feet, which occurred in 1988, Without the necessary dam repairs, the reservoir could become unusable through further storage restrictions or catastrophic failure, resulting in the loss of up to 20,000 acre-feet of irrigation releases from the reservoir. . . Water Qualitv Limited data related to water quality is available for the South Platte River at Julesburg, The water quality of the river at this location is expected to be similar or slightly lower In quality than water diverted for irrigation at the Harmony Ditch headgates, due to the Julesburg gage location farther downstream where river flows primarily consist of irrigation return flows during much of the year, The significant water quality parameters related to irrigation water supplies has been summarized for several years of water quality records obtained for the South Platte River at . 11 .