AbstractWith attention focused on flood hazard risk from place to place on a whole flood plain before and after flood hazard reduction and mitigation countermeasures are implemented, the present study proposes a method for evaluating flood hazard risk described using a local inundation depth and its frequency of occurrence. The method is composed of a rainfall run‐off model, a 1‐D channel flow model, a depth‐integrated 2‐D flood model, and several sub‐models, such as of a potential damage curve and an evacuation rating curve. To test the applicability of the proposed method, a flood plain located in the northern lake area of Shiga prefecture is chosen for discussion. The spatial distribution of damage resulting from each flood is thus evaluated before and after countermeasures are implemented.