Complex composed of two very different wetlands located on the Atlantic watercourse Oued Al Maleh. The main entity is the mouth of the river, which is currently reduced to a small salt steppe flooded temporarily. The second is a former small dam lake located 30 km from the mouth. Very silted, the latter gave birth to a dense and tall tamarica grove that extends the dam lake upstream.

The site is home to a remarkable flora, among which there are two rare forms (Atriplex semibaccata, and Polygonum balansae ssp. rhizoxylon endemic species) and one vulnerable (Ruppia maritima). The avifauna of the Mohammedia complex has at least 80 species; this diversity is closely linked to the diversity of biotopes. Six remarkable species frequent the site during wintering and/or migration: Marmaronetta angustirostris, Netta rufina, Tadorna tadorna, Phoenicopterus ruber, Phoenicopterus ruber, Platalea leucorodia and Larus audouinii.