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76. The determinations included in this section may be summarized as follows: (1) It is more economical to provide pipe capacity / to permit delivery of Lake Mead water to the urban area at the maximum monthly rate of con- l sumption than to provide less pipe line capacity] and local storage to meet the deficiency. (2) A pipe line with a capacity of 30.0 MOD will be adequate until about the year 1980. A 60.0 MOD pipe line will supply all requirements of the District, with the exception of "Other Agricul­tural Lands" until the year 2000. (3) The 34—year cost of two 30.0 MOD pipe lines con­structed at intervals of 34 years is 1.36 times the 34—year cost of a 60.0 MOD pipe line con­structed now. (4) The economical diameter of steel pipe line with a maximum capacity of 30.0 MGD and an annual average water usage of 20.0 MGD is 40 inches. (2) Pipe Line Routes - Numerous direct routes for a pipe line between Lake Mead and Las Vegas can be found. Three possible routes are shown on Figure 22. Pipe sizes and the static pumping head remain the same for all the lines selected. Dynamic pumping head, orpipe friction, is a function of length. It does not appear that any of the routes have any appreciable advantage over each other, hence the most advan­tageous route is the shortest route. The lengths of the three pipe lines shown are approxi­mately as follows: