Those do. Unless those gutters are connected to the sanitary sewer system, they do end up in rivers, then lakes. I can thank TG for why the label for 2,4-D based products got highly restrictive. Independent CPOs in the states where TG works can thank them for why both the citizens and regulatory agencies have a real beef against lawn applications.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738