A one-page info sheet on the Sawmill River in Yonkers, NY
Note-- in the years since I first made up this info sheet, the city of Yonkers has daylighted the final portion of the Sawmill River. It is now the centerpiece of a wonderful little town plaza and city park, with the above-ground stream visible before flowing into the Hudson. (This is Larkin Plaza, right near the Yonkers Metro-North station.)
I made these info sheets originally just as a way to tell people about the old streams and the sewers that have replaced them in NYC. I thought it was funny, for information about old streams that no longer existed, to present it as a flyer for a tour that didn't actually exist either. It was only a few years later than I began to develop actual walking tours where I would take people above-ground along the old routes of these streams. We only walk above-ground, but we peer down a few manhole covers along the way so that we can actually see the water flowing below (which is nowadays a mixture of natural groundwater and combined sewage together).