Colorado river.Colorado River near Page, Ariz.Photo courtesy trodel via FlickrIn this ongoing series of features, slideshows, and discussions, we explore the complicated and often dramatic relationship between urban rivers and the people who defend and rely on them. Where does our water come from? What kind of convoluted journey does it make on its way to our taps? How do we think about its critical role in building a sustainable urban future?

We start with the Colorado, then head to New Jersey’s Passaic, taking a hard look at how we’ve poisoned it. But that’s just the beginning. Come back each week for a new installment of our travels down some of America’s most important rivers.