An urban drainage system conveys storm water from the upstream to the drainage point in the towns and cities. The most important task of this system is to keep the streets and buildings from flooding. In this context, a cost effective solution would be to utilise the existing sewerage systems capacity by providing control structures such as control gates at suitable locations in the sewerage system, which is controlled and operated using suitable control strategy. This paper presents the development of a fuzzy rule based model for effectively reducing the surface flooding in the affected areas through improved operation of an urban drainage system.