Ghezala Earth Dam was built in the North West area of Tunisia, located west of Mateur City. First full filling of reservoir, of storage capacity close to hundred thousand of cubic meters, started in 1985 and lasted two years. The foundation of dam is essentially composed of a consistent clayey marl layer. At lower level of the dike's body a pipe, made up of reinforced concrete, has been designed for water evacuation from upstream side to downstream side. The pipe structure is composed of eleven sections of 15 m length each. During dam exploration, over twenty six years, a monitoring system permitted, in particular, the measurement of consolidation settlement which occurred in the soil foundation. This follow up made possible the observation of cracks which mainly occurred in central portion of the pipe of evacuation as result of differential settlements. In this context, a 2D numerical simulation of the dam foundation was performed by using the Mohr Coulomb behavior for the dam's material and the soil foundation. Numerical predictions of the evolution of consolidation settlement were compared to recorded ones. A good agreement between predictions and in situ records confirmed the effectiveness of adopted modeling for the studied case history.