Into what other river does the river fed by the spring whose name means "Blue Pot" feed?
Blau (Danube) The Blau (] ) is a 15 km long river in Baden-Württemberg, southern Germany, and a left tributary of the Danube. The source of the Blau is the karst spring of "Blautopf", in the town Blaubeuren, in the Swabian Jura. It flows east through Blaustein to the city of Ulm, where it empties into the Danube.
Black River (New York) The Black River is a 125 mi blackwater river that empties into the eastern end of Lake Ontario on the shore of Jefferson County, New York in the United States. The origin of the name is not clear, but it may stem from the natural tannic acid that darkens the water in places. The river flows in a generally northwest direction, with its valley dividing the Adirondack Mountains on the east from the Tug Hill region to the west.