AZ vs. CA:02 California Exhibits, Vol II; Nos. 58-113A

page 9

-9- Location of be taken for a period of at least a year; but, as the Colorado is an International and Interstate stream, this work is peculiarly the prerogative of the Government and I think should be undertaken by it. Drainage Area The drainage area of the Colorado, according to the Report of the U. S. Geological Survey, is 225000 square miles. The Gila, with a drainage area of 66000 miles enters the Colorado below our headgates. This leaves for our supply, an area of 159000 square miles the greater part of which lies in the high plateaus and mountain regions of Arizona, New Mexico, Utah, Colorado and Wyoming. It is impossible to approximate the mean precipitation or run off for the entire area, but if we assume that a depth of 2 inches over this area finds its way into the river, it would give a mean flow for the year of approximately 23400 cubic feet per second. I believe that the mean flow for the summer months, when the greatest amount of water will be required, will exceed this, since the greatest flow of the river is during the summer. Ordinarily the river begins to rise in the latter part of March, reaches its high water stage in May or June and then falls gradually, reaching the low water stage in September or October. In proof of this statement, I append to this report a diagram marked W. S. 2. This diagram was compiled by Mr. W. S. Hawgood, Resident Engineer of the Southern Pacific Co. Mean Flow High Water Period