"When I first got to L.A. in 2002, I started a satire website, where my business partner and I made fun of all things Californian, including the L.A. River. But I've come to love the bizarre L.A. River. You've got manmade monstrosities beside age-old nature. The Sepulveda Basin Recreation Area is less than a mile from one of the busiest freeway intersections in the world, but you'd never know it when you're paddling amid sycamores, willows, grapevines, and egrets.

"I never set out to be an activist, only to respond to a need in my community: to help revive the L.A. River. One day in 2008, my wife overheard me talking about paddling the 51-mile river and figured it would make for dramatic footage as a five-minute short for her new production company. I think she hoped for scenes of me being hauled off to jail, handcuffed to my kayak. She didn't quite get that, but she ended up with Rock the Boat: Saving America's Wildest River, a 54-minute environmental documentary.

"After that, I began talking up the idea of guided trips for the general public. I hatched a pilot boating program in 2011 with a coalition of local partners, and in 2012 L.A. River Expeditions branched off to run its own trips. There are about 15 soft-bottom miles, and that's usually where we go.

"Our ideal curriculum, if you will, would be to show Rock the Boat in community settings and use it as a way to prepare people—especially urban youths—to paddle the river that's in their own backyard. Then they'd go back to the communities or schools to process that experience and continue learning about things like watersheds, wildlife, public access, leadership, and community involvement. We've already managed to change many people's notion of the river as a ditch to that of a waterway with lots of potential. Nature doesn't have to be something that only happens out there beyond the city."