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D. Note: Since peak flows occurred infrequently, it was assumed that limited surcharging would be acceptable. I I I I I I I I I I I I I I I I I I I c. SlImmaJ:y of Pipe Sizes and Costs - Non Pressure Pipe. The following table summarizes pipe sizes and costs required for the 4 different demand scenarios (from the 3 preceding tables). Detailed cost tabulations are given in Appendix C. For preparing preliminary estimates, the costs were based on using one pipe size for both segments. Table V-4 Summary of Pipe Sizes Reqpired Demand Sec. 2 (1900') Cost of New Pipelines Sec. 3 (20,100') Normal Operation: 3.3-3.8 MGD 10" 12" $1,218,000 Emergency Operation: 7.3 MGD 14" 13.3 MGD 16" 14" 18" $~,434,000 $1,824,000 ALTERNATIVE 2 - NEW PIPELINE DESIGNED FOR PRESSURE FLOW 1. Method for Analysis of PresSllri7M Pipeline. Calculation of pipeline capacity for a pressurized system is simpler than non- pressure flow since the pipe always flows full and air adjustment is not needed. The entire pipeline can be analyzed as one section. Capacity is based on overall average slope, which is calculated from overall head and total equivalent length. Assuming water exits the pipe at atmospheric pressure, the hydraulic grade line (HGL) will be the same as the average ground slope. However, an analysis based on overall average slope is only possible if the pipe profile is concave shaped. If it is not, and there are certain flatter sections, particularly in the upstream areas, the hydraulic grade line will pass below the profile of the pipe and a vacuum could occur. Pressurized flow in the pipeline was analyzed for 3 segments: 1) from Cabin Reservoir water surface to the Wye (this requires installing pipe through the outlet box), 2) from the Cabin outlet box to the Wye, and 3) from the Wye to the WTP. The upper line (to the Wye) must be designed to leave sufficient residual pressure at the Wye (during peak flow) to supply both the Palisade WTP and the Ute WTP. V-15