The Ihme is a 16-kilometre (10 mi) long river in Lower Saxony. It gives its name to the locality Ihme Roloven and is a left tributary of the Leine. Its source is in the village Evestorf. After about 6 kilometres (4 mi), the Ihme reaches the city of Hanover, where it flows into the Leine. In order to protect the city center of Hanover from flooding, much of the water of the Leine is rerouted by a ditch into the Ihme.