river, northwestern Germany. It rises on the south slope of the Teutoburger Forest and flows generally northwest and north through the Länder of North Rhine-Westphalia and Lower Saxony to the east side of the Dollart (baylike enlargement of its estuary), immediately south of Emden. It flows around the island of Borkum after passing through the Dollart and along the western edge of the Lower Saxony Wadden Sea National Park on its way to the North Sea. There is a marked winter maximum and summer minimum flow. The Ems is 230 miles (371 km) long.

Between 1892 and 1899 the river was canalized to connect it with the Dortmund-Ems Canal in order to provide a German waterborne outlet for the Ruhr industrial district. There are also connections with the Rhine-Herne Canal and the Mittelland Canal system. Traffic northward on the canal system is mostly in coke and coal from the Aachen and Ruhr coalfields; southward, the traffic consists chiefly of imported raw materials and foodstuffs.