Natural flood management is when we use, alter or restore landscape features to reduce the impact of flooding. This catchment-based approach is an evolving area of work in the uplands, and is currently being developed by a range of partners including the Environment Agency and Natural England.
Wildfire contributes to the risk of flooding because it is probably the greatest threat to peat. Areas of peat left exposed by fire are unstable and subject to wind and water erosion. Eroded peat is washed into watercourses along with silt from any mineral base material that has become exposed as the peat is removed. This has implications for water quality on catchments as well as adding to the debris that can increase the frequency and impact of flood events.
Research into the effectiveness of various land management techniques – including peat restoration – is still in its infancy, but partners are looking at how this could be applied to upland catchments within the South Pennines. For example, Water@Leeds (part of the University of Leeds) has applied a hydrological model to identify the impact of land management upon flow to a 5.7 km² headwater tributary for the River Calder. Re-vegetation modelling was conducted under a series of rainfall events. Different land cover regimes in different parts of the catchment have been evaluated with regards to impacts on flow. They have identified that the establishment of sphagnum adjacent to streams and watercourses could provide some potential for a modest reduction of flood peaks.
The enclosed videos show a realisation of sphagnum regeneration in these riparian buffer strips, which would be efficient for modest flood reduction during a storm rainfall event.
Pennine Prospects is one of several organisations that has been commissioned by Calderdale Council to help deliver the DEFRA Flood Resilience Pathfinder Project in Calderdale. This project aims to develop an approach that can assess the impact of land management on flooding as well as identify issues and sites needing further work. It will also support community resilience programmes in terms of education and supplying information.
The project is managed by Countryside Services (part of Calderdale Council), with Pennine Prospects taking responsibility for developing the ‘grab a grid’ initiative. Meanwhile, Calder Futures will deliver river stewardship and Treesponsibility will deliver on education and community work. In addition, water@Leeds has been commissioned to validate this work as part of a wider project looking at how different land uses could help reduce surface run-off. As well as producing a report, Pennine Prospects has produced a video on the issues.