Water scarcity has always been a problem in the southwestern desert, with practically everyone relying on one river, the Colorado, to quench their thirst and the thirst of their crops. Increased water demands coupled with a long protracted drought in the Upper Colorado River Basin has created a potentially dire situation. The effects can be seen in Lake Mead, the giant lake along the border of Arizona and Nevada. Lake Mead has reached its lowest levels since 1937, the year the Hoover Dam was completed.