Much of the opposition to this plan is along political lines: Lake Powell is legally considered the Upper Basin's water, and Lake Mead belongs to the Lower Basin. The Friends of Lake Powell have called this an attempt to steal water from the Upper Basin, to avoid a shortage in the Lower Basin. The Upper Basin has released 107% of its obligation from Lake Powell since 2000; therefore, falling levels in Lake Mead are a result of water overuse and waste in the Lower Basin states – a "structural deficit". There are also arguments for storing water in Powell: Lake Mead, with its much lower elevation and hotter climate, has a considerably greater evaporation rate than Lake Powell. In addition, a 1983 study by Larry J. Paulson of the University of Nevada showed that the cold water discharge from Glen Canyon Dam has led to a significant reduction of the water temperature, and thus evaporation, from Lake Mead.