The Narrow Gera is a long tributary of the Gera River, which begins in the center of the Thuringian capital Erfurt and runs parallel to its main course in the flat center of the Thuringian Basin until shortly before the district town of Sömmerda .

Outside the urban area, it flows between Nöda and Riethnordhausen close to the foot of the hills.

At Haßleben, its course is separated from that of the main Gera river by the Kantorberg and another hill.

On the outskirts it takes up the Wilder Graben, which previously flows parallel to the Gramme, but does not branch off from it.

On the western edge of Werningshausen there is a connecting ditch between Schmaler Gera and Gramme at Lindenstrasse, but only 0.6 km north of the village the two bodies of water unite, whereby the Gramme, which was previously close to the edge of the village, is in the bed of the previously in a wide arc around the village Schmalen Gera, which is led around, continues to flow.