A flood corresponds to the slow or rapid overflow of water from its usual location. This inundation in general affects lands adjacent to a watercourse or variable level area (for example, a middle or major bed). This requires a flood protection study to define the areas that will be attenuated by the overflowing water and to take the necessary safety measures based on the results of an engineering study (for example, the construction of supporting walls, the widening of hydraulic structures, and the construction of reinforced concrete channels). In order to control flooding, a long series of flow measurements is necessary, which unfortunately is not the case in most cases. The hydrometric station of Ifni controlling the watershed of Oued Adoudou on an area of about 662 km2 gave us a series of maximum daily rainfall for a period of 18 years, from 1996 to 2016, which fit well to several laws such as Gumbel’s law, Log normal, Person III, and Gamma. From the fitting line, the values of probable rainfall for different return periods were determined; 46.1 m3/s for a 10-year return period, 54.85 m3/s for 20 years, 66.1 m3/s for 50 years, and 74.7 m3/s for 100 years. In order to estimate the flood flows by empirical formulas based on precipitation, the rainfall-flow correlation was verified by the HEC-HMS calculation code. Hydraulic modeling was made based on the calculated flows of the Oued, the object of the study, by the hydraulic modeling software HEC-RAS. This allowed us to identify the flood-prone areas and from the latter to protect the population and their property through the development of development schemes for protection against flooding.