ABSTRACT
A culvert design may vary from a simple geometry (standard culvert) to a hydraulically smooth shape (minimum energy loss culvert). Based upon current design practices, the hydraulic characteristics of the culvert are the design discharge, the corresponding water depth in the natural stream in the absence of the culvert structure, and the maximum acceptable afflux. This chapter presents a complete design application based upon a real case study in Australia. A new approach is developed for hydraulic engineering design guidelines of fish-friendly box culverts with a focus on fish species with weak swimming capability. The barrel size is selected by a test-and-trial procedure in which both inlet control and outlet control calculations are performed for design flow conditions. A bridge design is more suitable alternative to a massive multicell box culvert structure. When the fish-friendly culvert design requires more cells than the optimum design for flood capacity, the revised design would operate with a smaller afflux at the design discharge.
