How cities like Portland and Chicago are breathing new life into their urban rivers

For decades, the Willamette River that runs through Portland, Oregon, was a look-but-don't-touch situation.

"When we first moved here, there was no way in hell you'd get in the water," resident Matthew Mangus said.

The river was contaminated by raw sewage and had been closed for swimming since 1924, but now things are very different. Willie Levenson, founder of the Human Access Project, helped turn the Willamette into a vibrant recreational space that officially became swimmable again in 2012.