Residence Times in Vegetated Stormwater Ponds

Bringing together lab work, field work, and computational modelling to present a complete picture of mixing processes in vegetated ponds.

Ponds are often placed besides roads or in developments in order to capture rainfall run-off. Their purpose is two fold; to help reduce urban flooding and to improve run-off quality.

This EPSRC funded project, 'Residence Times in Vegetated Stormwater Ponds', focused on quantifying the latter. The project improved our understanding of how vegetation impacts water movement in ponds and how this can be modelled. This allows for better predictions of the ability of ponds to improve water quality. The work was a collaboration between the University of Sheffield and the University of Warwick.

As of 31 August 2016, this project was successfully completed. We thank our researchers, project partners, guest speakers, and everyone else who has participated. While dedicated funding is no longer available, we look forward to continuing to develop our knowledge of vegetation, mixing, CFD modelling, residence time distributions, and stormwater ponds with you in the future as we are able.

See our outputs page for the full list of project related outputs and publications.

News

27 March 2019

The article 'A CFD‐based mixing model for vegetated flows', based on work from this project, has been published. This article describes a framework for predicting flow-field, turbulence, and mixing within vegetated environments such as ponds and wetlands using Computational Fluid Dynamics (CFD) computer modelling. Supplementary materials available with the article include the ANSYS Fluent User-Defined Function (UDF) code used in the calculations.

The image to the left shows the surveyed bathymetry of a real stormwater management pond. The inlet is located to the top right and the outlet at the bottom left of the image. The green shaded area indicates the pond's marginal vegetation.

The animation on the right illustrates solute transport through this real pond as determined by the newly published CFD framework. There is clear evidence of short-circuiting in the main flow field as the solute that moves through the unvegetated area arrives at the outlet very quickly in comparison to solute that travels through the vegetated areas. This demonstrates the slower travel times associated with flow through vegetation.

This case study will be reported in a forthcoming presentation at NOVATECH 2019. For further information about the background research and the modelling approach, refer to the outputs page.