By Wesley Houp
To say a river is a living system is a scientific truism that even the most scientifically uninitiated intellect can grasp with minimal cognitive stretching: rivers teem with life, from unicellular diatoms to aquatic invertebrates and on up to vertebrata, fish, amphibian, avian, mammalian. Watersheds branch like trees, only their life-force moves in reverse from tiniest green-shoot to broad trunk, the faintest spring or rill gaining momentum, joining forces with other rivulets, debouching into larger creeks that eventually embolden the flow of master streams. Geologists, taking the long view of things, give rivers human-like agency, noting how they “capture” and “pirate” this or that watershed, or “desert” and “abandon” this or that channel, ever insisting on a course of least resistance. Rivers, like so much of life on earth, adapt to physiographic vagaries and persist through course of time as if accumulating the knowledge of experience.