An idea for cleaning up rivers that was developed by a man in Baltimore, Maryland, is now at work in one of the most polluted rivers in Panama. It is yet another example of how small stories can offer inspiration far beyond the place where they started.

Baltimore’s Trash Wheel Family started with an idea sketched on a napkin by sailor and engineer John Kellett, who was disturbed by the garbage that flowed downriver after storms. He sketched plans for a machine powered by an old-fashioned water wheel that would catch the trash before it got into the harbour. He had no idea that it would spawn a social media family with a worldwide following or find a way to help Baltimore’s residents turn garbage into electrical power.