The Bureau of Reclamation projected that once Lake Powell filled, the total bank storage would stabilize at approximately , and henceforth would fluctuate depending on water levels in the reservoir. The actual loss was , twice the initial prediction, but river flow data indicates that further leakage after 1980 has been negligible. However, according to a 2013 study by hydrologist Thomas Myers for the Glen Canyon Institute, the reservoir continues to lose about each year due to leakage. According to USBR data for water year 2015 (a year when Lake Powell did not experience a significant overall gain or loss in volume), Lake Powell lost a total of to evaporation and only to leakage.