Mohsen Monadi - PhD Candidate, Department of Civil Eng., Faculty of Eng., Urmia University, Urmia, Iran.
Mirali Mohammadi - Associate Prof. in Civil Eng., Faculty of Eng., Urmia University, Urmia, Iran. and The University College of Science & Technology (Elm-O-Fann), Urmia, Iran.

The purpose of this study is to find an optimum height of the flood levee’s at the downstream reservoir dams, so that the objective function which is benefit to cost of flood levee construction ratio (B/C) becomes maxima and all requirements are met. Therefore, with regard to flood control in the downstream of the reservoir dam, the optimum height of downstream flood levee is calculated. A simulation of the region and the flood routing in the reservoir of the dam are carried out using the (HEC-RAS) software and the Hydro-Rout Models, respectively. A Real Genetic Algorithm (RGA) is employed to maximize the benefit/cost ratio of the reservoir dam construction. Thus, a mathematical programming in MATLAB software has been prepared and then linked with the optimal programming (RGA) to maximize the benefit/cost ratio of the Sonateh reservoir dam in Kurdistan province constructed on the Khor-Khoreh Chay River is taken as a case study to verify the results. The results reveal that an optimum levee height is obtained equal to 1.35m. The results of Sonateh dam construction indicate that the optimum levee’s height obtained by using the new method which is more accurate and efficient.

Optimization, Height of Levee, Sonateh Reservoir Dam, HEC-RAS, Genetic Algorithm