Combined Sewer Overflow is basically the discharge from a combined sewer system that is caused by snowmelt or storm water runoff. The Gowanus canal is an example of where combined sewer overflow may be found. The Gowanus canal is where one can actually notice that combined sewer overflow has happened and basically have these green signs indicated that the public should not fish, swim, or go canoeing and kayaking on the canal due to rainwater being mixed with the untreated sewage. Combined sewer overflow is happening when the sewers from our homes, storm drains, and business and commerce go through the sewer at once and don't follow a path leading to the sewer treatment plant but end up overflowing and going towards another path allowing untreated water sewage into streams and rivers. This mostly happens when it starts to rain and to much rain gets into the sewer leading to an overflow and making it come out towards a path that leads towards streams or rivers. The Gowanus canal is affected by combined sewer overflow because when it happens the water becomes polluted affecting the water quality and not only does it affect the water, it also affects the species that live around the canal and the homes and the businesses because once the water is polluted it gives off a smell that not only the species surrounding the canal may not like but also the people live and working around the canal as well.