Yesterday I participated in the Charles River Conservancy’s annual City Splash event at the Arthur Fiedler Pier just off the Esplanade. Jumping into Charles River may seem frightening to some, after all this is the river that inspired the song “Dirty Water.” But this event is partly to show that decades of work and investment into cleaning the river making it one of the cleanest urban rivers in America. I can’t tell you how exhilarating is is to drop into the river’s cool waters after a long day of work and float while looking up at the Back Bay skyline. This was my second City Splash, and I hope to do it again, maybe even more than once a year. The Charles River Conservancy is working to make Charles River swimming a permanent summer feature by building a swim park adjacent to North Point Park. This wouldn’t be the first time as the North End Beach allowed residents of local tenements a place to bathe over 100 years ago (although there was probably less concern for water quality back then).