Alex Fraser is a river engineer with CH2M and ordinary member of the Chartered Institute of Water and Environmental Management (CIWEM) Tyne and Humber Branch Committee.
Specialising in flood risk management, he has worked on a range of projects employing solutions including upper catchment natural flood-risk management, flood storage areas and urban flood protection.
Having managed the Government funded Property Level Resilience Grant, Alex has experience working with property level interventions of both a resistant and resilient nature.
In this article he argues that the property level resilience sector needs to become better integrated with Risk Management Authorities and the consultants that they commission. This can be done by open dialogue, knowledge and information sharing and working collaboratively on projects at an early stage.
Delivering a more sustainable approach to managing flood risk
NFM, SuDS & PLR are more than just acronyms, they represent a suite of techniques that deliver a more sustainable and responsible approach to managing flood risk.
- Natural Flood-Risk Management – reduces catchment contributions to flood peak remotely from the vulnerable area;
- Sustainable Drainage Systems – reduce runoff from impermeable areas & reduce pressure on drainage systems near the vulnerable area;
- Property Level Resilience – reduces a property’s vulnerability to flooding, protecting the most vulnerable and valuable areas from damage.
By improving water management at each stage of the hydrological cycle we achieve a more sustainable water management package. It is important all parties take responsibility, it would be unfair to expect farmers to reduce discharge that could impact profits if vulnerable communities don’t also invest in resilience themselves.
NFM is an innovative approach to flood risk management, particularly at the national scale. The background to the approach is well grounded in environmental management, but the current method of delivery is an exciting challenge for the sector. In achieving this new way of working, the use of complex fully spatially distributed and physically based hydrological models is a pioneering development. Their use does however, rely upon evidence based assumptions. These assumptions are perhaps most prominent in proposals for tree planting or soil improvement, the assumption being that current use generates high runoff and that interventions will improve this. Where assumptions are made about current condition or potential improvement, there is uncertainty about what impact these interventions may have upon the system. My work at Durham University (soon to be available on the e-theses portal) demonstrated the uncertainty surrounding the potential effectiveness of such interventions within the CRUM3 fully spatially distributed and physically based hydrological model.
As a result of this uncertainty I see an important role for the PLR sector, in delivering improved resilience at the vulnerable community. This is made more pressing given the release of new residual uncertainty guidance from the Environment Agency that all flood resilience schemes now need to adhere to. This, in my opinion, the PLR sector needs to become better integrated with Risk Management Authorities and the consultants that they commission. We can do this by open dialogue, knowledge and information sharing as well as working together on projects at an early stage.