In this paper, an hybrid metaheuristic based solution is proposed to solve the annual optimal hydro generation scheduling problem. The problem of the hydro generation scheduling is formulated as a continuous non-linear optimization problem and solved using enhanced combination of metaheuristics: random greedy, evolutionnary algorithm and, pseudo dynamic programming. The obtained results upon one year of the application of the proposed method on the horizon of one year of hydropower generation (while in the literature most authors are limited to one week) demonstrate the efficiency of the proposed algorithm.