The five Great Lakes, and the rivers, channels, and lesser lakes that connect to them, hold a fifth of the world’s surface fresh water. But below-average precipitation, increased evaporation due to above-average temperatures, and mounting water consumption is driving water levels here to record lows.

(Text adapted from and photo shot on assignment for, but not published in, "Down the Drain: The Incredible Shrinking Great Lakes, " September 2002, National Geographic magazine)