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� <br />P/anning Considerations - Technical <br />i <br />RRWCD Compact Compliance Pipeline <br />Scope of Work <br />August 30, 2007 <br />Well Field Considerations <br />Slattery Aqua Engineering, LLC (Slattery} has determined that the existing wells to be considered <br />for compact compliance supply should be located a minimum of ] 0 miles to the north of the <br />North Fork Republican River. Therefore, we propose to initially investigate the wells in a zone <br />bounded by County Road/Section Line 46 on the south, the Nebraska State Line on the east, <br />County Road/Section Line 54 to the north, and State Road 385 to the west. <br />Most of the wells irrigate 225-acre circles within a mapped quarter-section (160 acres). The <br />existing wells are assumed t� mostly be permitted at 400 acre-feet per year capacity (slightly <br />more than 3 feet per year on the irrigated circle), and estimated to have a historic consumptive use <br />ranging from 188 AF/YR (18 inches of irrigation water applied over 125 acres) to 313 AF/YR (30 <br />inches of water applied over 125 acres). With these assumptions, the program could require <br />between 32 and ] Q6 existing wells to be "retired," depending upon their actual historic use. <br />Ptanning of the project will consider using fewer, larger, higher capacity welts in place of the <br />existing 400 AF/YR wells to reduce the complexity of the infrastructure and system operations. <br />Also, it should be possible to move the water rights from a number of setected wells to a single <br />well withdrawing the total historic consumptive use associated with the selected welis and this <br />option will be explored with Slattery. <br />Puma Station and Pipeline Considerations <br />The "retired" wells must be connected to the Pipeline for delivery from the well field to the <br />Republican River. Consideration will be given to providing a smalI storage basin to reguIate the <br />inflow from the well pumps and the pipeline booster pump. <br />Various types and sizes of pipe will be evaluated during this study. Life cycle costs including <br />initial instailation, replacement, and operation and maintenance costs will be considered. The <br />types of pipe that will be evaluated include reinforced concrete (12CP), steel, ductile iron, <br />polyvinyl chloride (PVC), and fiber-glass. Several alignments for the augmentation pipeline will <br />be considered during this study to identify the preferred alignment. <br />Outfall Structure Considerations <br />The outfall structure of the Pipeline is expected to be located as ciose as possible to the Colorado- <br />Nebraska state line. If local considerations so indicate, the Pipeline could discharge to the river at <br />an upstream location near or in the Town of Wray. With this location the pipeline would meet <br />other objectives than simply compact compliance and will only be considered with the <br />concurrence of the District. <br />Operations and Controls Considerations - <br />A complex well field and pipeline system is expected to require operations and controls that are <br />flexible, accurate, real-time and remote. Tn any given year, this system could be expected to <br />deliver between zero and 20,000 acre-feet of water to the North Fork Republican River gauging <br />station. 6valuating several parameters simultaneously will allow for immediate decisions and <br />adjustments to the system deliveries and timing. Tndividual or group well performance and yield, <br />demand relative to stream flow, timing of augmentation flow relative to irrigation dernands, and <br />any impacts to flow by adjacent users (i.e., Laird Ditch or Pioneer Ditch) or infiltration will be <br />factors to consider in developing an aperations and controls program specifically tailored to this <br />system. During this study, we will identify critical parameters to be monitored, measured and <br />adjusted year to year to optimize the perFormance of the augmentation pipeline. <br />� O <br />�j E � . GEI Consultants, Inc. <br />