Modelling NFM in Calderdale

Prioritising Natural Flood Management (NFM) interventions in Calderdale

A rainfall run off model (SD-TOPMODEL) developed at the University of Leeds is being used to help prevent flooding in the Calder Valley. The digital model will show the flow of water from hillslopes to the river. This will enable the project team to analyse how and if existing landscape features, such as walls, gates and hedges, and new measures, such as hedge and tree planting, reduce flood risk by storing and slowing flood water.

We investigated the link between land use and management practices and flood levels in the Upper Calderdale valley and the benefit that different landscape-wide NFM interventions might have on reducing flood levels in the valley.

The role of iCASP in this project has been to provide the modelling expertise and the scientific evidence for the Calderdale Flood Action Plan to help prioritise the siting of future NFM schemes. Conclusions will be used to support business cases for further NFM funding for Calderdale and evaluate work already done. It will also help identify research gaps and help communities to understand how working with natural processes can have an impact on flooding.


Environment Agency
Calderdale Council
Calderdale NFM Operational Group
University of Leeds
Yorkshire Water

Project Team

Tom Willis – iCASP Impact Translation Fellow (link)
Sally Kelling – Environment Agency & Calderdale NFM Operational Group
Jo Arnold – Environment Agency & Calderdale NFM Operational Group
Rosie Holdsworth – Calderdale Council & Calderdale NFM Operational Group Granville Davies – Yorkshire Water & Calderdale NFM Operational Group
Dr Megan Klaar – University of Leeds
Professor Mike Kirkby – University of Leeds
Dr Mark Smith – University of Leeds


November 2018 – 2021


Technical Report

Summary of Calderdale Modelling Report

    Appendix B: Hebden Bridge maps

      Appendix C: Upper Calder maps

        Appendix D: Jumble Hole maps

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          Summaries of the main results for different land management practices and NFM interventions. They include a description of the investigative work carried out and the impact of the land management/intervention scenario on flood levels for the three sub-catchments used in our project.

          Project updates