Upper Rhine Bovenrijn

Shortly before Wijk bij Duurstede the Kromme Rijn (Winding Rhine) branches off and flows northwest towards Utrecht.

Soon after Wijk bij Duurstede the Nederrijn crosses the Amsterdam-Rhine Canal, which provides a link with the Waal; and from this point to its junction with the Noord (linking it with the Merwede) it is known as the Lek.

Within the city and port area of Rotterdam the river successively bears the names of Nieuwe Maas (New Maas; at IJsselmonde, junction with the Hollandse IJssel), Het Scheur and the Nieuwe Waterweg (New Waterway). Between the oil port of Europoort and the ferry port of Hoek van Holland (Hook of Holland) the Nieuwe Waterweg flows into the North Sea.

The northern arm of the Rhine is known as Pannerdens Kanaal as far as Arnhem, where the Gelderse IJssel branches off to flow into the IJsselmeer. From Arnhem to Wijk bij Duurstede it is known as the Nederrijn (Lower Rhine).

The southern arm of the Rhine, known as the Waal, flows past Nijmegen and continues broadly parallel to the Maas, a short distance to the south (connected by two canals; the Maas continues as the Bergse Maas and the Amer, and after its junction with the Nieuwe Merwede flows into the Hollands Diep). At Tiel the Waal is joined by the Amsterdam-Rhine Canal, which provides a connection with the Lek. From the old outflow of the Maas into the Waal near Gorinchem the southern arm of the Rhine is known as the Merwede. At Dordrecht, where the Nieuwe Merwede branches off to flow into the Hollands Diep, the Merwede divides into the Noord (connection with the Lek) and the Oude Maas (Old Maas). The Oude Maas then flows south past Rotterdam and joins the Nieuwe Maas (Het Scheur) opposite Vlaardingen.