There's an old joke about Arizonans and their rivers. An Arizona man is on vacation in Germany, and he visits the Rhine River. "Isn't it beautiful?" one admirer asks. The desert dweller responds, "Sure, but I can't see the river with all this water in the way!"
The joke reveals the complex ways that water structures the Sonoran Desert and the lives of its peoples. Water follows a complex cycle, one that has been altered by human settlement.
Presently, Phoenix receives its water from the Salt River Watershed as well as the far-off Colorado River through an intricate network of canals, many of which are still a visible part of the landscape.
Groundwater reserves are another significant supply source for Arizona, with 40% percent of its water coming from aquifers. Water enters underground through recharge along mountains, recharge from streams, or artificial recharge, and leaves through wells, discharge to streams, or riparian plants. Another 39% of Arizona's water comes from the Colorado River, which also flows through six other states and Mexico. More than a century of water rights cases have been filed to determine how much each state and the two nations can claim from the river.