Oum Rabie or Oum Errabia or Mou Arbiâ (Berber: Wansifen, Arabic: أم الربيع, French: Morbêa) is the 550 km Moroccan river with a flow of 117 m3 / s. It takes its source at an altitude of 1 800 m in the Middle Atlas, 40 km from the town of Khénifra and 26 km from the town of M’rirt, this important river takes its source from the height of the jebel Hayane in the rural commune Of Oum Errabia and flows into the Atlantic Ocean at the level of the municipality of Azemmour.

The Oum-Er-Rbia basin is the cornerstone of Morocco’s hydroelectric and irrigation network, which covers an area of ​​35,000 km². The Oued Oum Er-Rbia, 600 km long, originates in the Middle Atlas at 1,240 m altitude and 40 km from Khénifra, then crosses the Middle Atlas range, the Tadla plain and Abda-Doukala, (the coastal Meseta) and flows into the Atlantic Ocean about 16 km from the city of El Jadida (Azemmour).

The Oum Errabia Basin is a complex of rivers, concentrating in the Middle Atlas (causse, meseta and dir), it is the river system including Oum Errabiaa, oued Srou, oued Chbouka. The centerpiece of the basin is on the main axis of the Oum Errabia (Oued El Abid). This basin was considered a hydraulic reservoir for a part of the country, and a set of eight dams was built there.

The Tanafnit El Borj dam, 25 km from Khénifra, is the first hydroelectric dam built in the village of Tanafnit, upstream from the Oum Errabia springs.