Hydraulic structures disrupt fish migration thereby contributing to declines in fish populations around the world. Methods for piping fish upstream over dams can offer much steeper lift than conventional fishways. We describe the lifting mechanism of a tube fishway, demonstrated using numerical modelling, verified by a physical model. Efficacy is demonstrated by safely lifting two species of Australian native fish over 8 m up an embankment. Significant volumes of water can be transported from a chamber at the foot of a dam over its crest using simple conduits and two valves. Unsteady flow contributes entirely or significantly to the volume of water lifted. We explore how this piped system could be scaled up, while controlling turbulence impacts on fish. We propose new methods of characterising hydraulic efficiency for fishways that recognise the energy used and the value of the water discharged.

水力结构破坏了鱼类迁徙，从而导致世界各地鱼类种群的减少。与传统鱼道相比，通过管道将鱼向上输送到大坝上的方法可以提供更陡峭的升力。我们描述了管鱼道的提升机制，使用数值建模进行了演示，并通过物理模型进行了验证。通过将两种澳大利亚本地鱼类安全地提升到堤防超过 8 m，证明了其功效。使用简单的管道和两个阀门，可以将大量水从大坝脚下的腔室输送到其顶部。非定常流动对提升的水量有完全或显着的贡献。我们探索了如何扩大这个管道系统，同时控制湍流对鱼类的影响。