Determining Bank Storage of Lake Mead

By means of a water budget, the bank storage at Lake Mead is evaluated. It is necessary to estimate a part of the inflow to the reservoir. A procedure for making this estimate based on the measured tributary inflow below the streamflow gaging station on the Colorado River near Grand Canyon is suggested. It is found that the amount of water going into and coming out of bank storage in a year is (as of 1965) approximately 6.5% of the quantity being stored or withdrawn from storage as determined by tables giving the relationship between elevation and surface storage. The percentage relationship of bank storage to surface storage is a marked reduction from that which occurred during the initial filling and the earlier life of the reservoir.