Rising in the mountains of Dogu’a Tembien in northern Ethiopia, it flows eastward to empty finally in the Giba and Tekezé River.

[1] The May Harena is a confined ephemeral river with an average slope gradient of 100 metres per kilometre.

The problem is exacerbated by the fact that most of the urban drainage from Hagere Selam is rapidly directed to this river.

On some steep slopes, exclosures have been established; the dense vegetation largely contributes to enhanced infiltration, less flooding and better baseflow.

[6][7] Boulders and pebbles encountered in the river bed can originate from any location higher up in the catchment.