Cause and Effect
To summarize:
Stormwater with a high level of TSS (and often other pollution, such as petroleum products from automobiles), as well as phosphorus and nitrogen (from pet waste, over-fertilization of lawns, and soaps, for example) is washed down the storm drains and frequently discharged into the tributary system of the Potash Brook watershed usually withouth treatment of any kind.
The volume and force of the stormwater runoff scour out the tributary channels, which creates significant erosion. The sediment and pollutants are to carried downstream locations, and ultimately to Lake Champlain.