Lake Powell is a reservoir on the Colorado River, straddling the border between Utah and Arizona, United States. It is a major vacation spot that around two million people visit every year. It is the second largest man-made reservoir by maximum water capacity in the United States behind Lake Mead. However, due to high water withdrawals for human and agricultural consumption, and because of subsequent droughts in the area, Lake Mead has fallen below Lake Powell in size several times during the 21st century in terms of volume of water, depth and surface area.(Wikipedia)