A once-floating dock was left high and dry by drought conditions that lowered the level of Medina Lake some 52 feet (16 meters). The lake, which provides water to Texas farmers and the city of San Antonio, is shrunken thanks to an ongoing drought that includes the driest, hottest 12 months in Texas' recorded history.

Across much of the western United States, similar conditions have caused cities, farms, and businesses to fear for the future of their water supply as demand outstrips availability.

"In the Southwest, if you look at the past three-quarters of a century when people were moving here and farming here and building dams here, all that activity was based on a much wetter period of time than we've had historically or what we're likely to have in the future," said Sandra Postel, founder of the Global Water Policy Project and the National Geographic Society's Freshwater Fellow.

Overall, nearly half the country currently faces drought, according to the U.S. Drought Monitor.

—Brian Handwerk

(See more drought pictures.)

Pictures: Drought Parches Much of the U.S.

Heat and dry conditions are causing hardships, from failed crops to forest fires.