Hydrodynamic modelling of leaky barriers in channels

Leaky barriers are introduced into river channels to slow down floods and encourage temporary storage on the floodplain. They are a nature-based solution, inspired by beaver dams and natural accumulations of large woody debris, and have been growing in popularity. However, their hydraulic effects are not well understood. This project addresses the evidence gap with hydrodynamic modelling.

First, computational fluid dynamics (CFD) simulations are being undertaken with OpenFOAM to explore how individual leaky barriers work in detail. As the OpenFOAM source code is openly available, further functionality is being added as part of this project. This is to make it more suitable for modelling open-channel flows. The CFD simulations will then be validated with experimental data from the hydraulic flume.

Second, a 1D hydraulic model with leaky barriers included as internal boundary conditions has been developed as part of this project. Results from the CFD simulations will be plugged into the internal boundary condition to simulate the wider hydraulic impact of leaky barriers. This can then inform planning and design.