The problems in concern with flood modeling which Engineers face, originate from predicted from level of water and flood forward speed basicly as a function of base of river and basin topography. But increasing flows which due to probable rain shower originated from global climate change and urbanization cause to increase calculation difficulties. On the other hand hidrolic models explain the water level to get reached in given in a flow, morphologic results of floods and flood spreading. However the basic difficulty is complication of current flooded from main river bed to floodplain. In spite of calculation of water level is a simple problem response given flow in channel with single section, the problem gradually gets complicated with water flooding from main channel to flood plain. Flood plains don’t only work as retard pool, also due to they carry flow the complication of current originated from this. There are several flow calculation methods in a main channel, a compound sectioned channel consisting of one or more flood beds. In this study, the discharge computation is carried out using Single Channel Method (SCM) and Divided Channel Method (DCM) known as classical methods. These methods have been applied to a compound channel given in literature. The computed discharge values were compared with the experimental discharge values, and the validity of these classical methods is investigated. The He method in the DCM method in compound channel gave better result than V (vertical) and D (diagonal) methods. However, since the SCM method gives fewer errors than the DCM method, it has been concluded that the SCM method is better suited to use in calculation of flow of the composite sectioned channels.