This paper describes for the first time an original foggara, different from the classical foggara (foggara of Gourara) which collects water from the Intercalary Continental aquifer. Located in the middle of the Mzab River, this hydraulic system called the Mzab foggara is intended to exploit the flood waters. Two missions were carried in 2009 and 2010 in the Mzab Valley to describe the hydraulic system. The Mzab foggara constitutes of a gallery of ovoid form 200 m long equipped with 9 air shafts and a 900 m long seguia. The foggara of the Mzab River can drain water flow of 5 m3·s-1 to irrigate western part of the palm plantation of Ghardaia (located 600 km south of Algiers).