About this project
Leaky wooden dams are being used as a significant component of many planned and implemented Natural Flood Management schemes.
Their low installation cost and simple design, has led to their widespread application, but with minimal design and limited critical assessment of best practice in design and construction. For example, informal designs that block the whole channel result in significant scour, producing elevated downstream sediment loads, impaired performance and, potentially, eventual failure.
Furthermore, the longitudinal spacing may interfere with natural pool-riffle sequences and the effects of constructing dams both in and out of phase with these features is unknown. Such dams thus provide a poorly constrained contribution to flood retention.
Alternative, more substantial, designs that are raised above mean low flow levels and constructed to retain known volumes of water, may limit their geomorphological impact to large flow events, but with largely unknown long-term impacts on catchment sediment load and geomorphology.
This project will use a combination of fieldwork, experiments and numerical modelling to assess the behavior of leaky dams of different porosities, installation heights and installation angles at different flow rates.
These results will be used to improve the design of leaky dams for natural flood management schemes (working with Forest Research, Yorkshire Wildlife Trust and others), both in terms of hydraulic effectiveness/efficiency and bio-geomorphological effectiveness.