Many people don’t know it, but there was once a brook running from JP along what is now Columbus Avenue and into the area around Forsyth Street on Northeastern’s campus. The Stony Brook, commemorated in the Orange Line stop of that name, was the source of water for many of the breweries along Pynchon Street. It was also the source of much misery in Roxbury and Boston due to its frequent floods. Over time, it was eventually culverted almost entirely, and now it runs underground in a pipe for the majority of its length.
There is an excellent history of the Stony Brook in blog form at http://stonybrookinboston.blogspot.com/. Start with the oldest post and read in reverse order.
There is also a very good view of the Stony Brook in this 1832 map of Roxbury from the JP Historical Society.