Natural flood management can increase flood resilience and deliver multiple other benefits to communities. But many flood risk management authorities believe it can be too challenging to put such measures in place on a large scale. Flood risk specialist Steve Cook suggests some reasons why and looks at how to better promote natural flood risk measures to see more widespread uptake.
Flood risk management authorities are being encouraged by governments across the UK to invest more in natural flood management (NFM) approaches, such as restoring meanders in rivers or creating coastal salt marshes to reduce the risk of inland and coastal flooding.
To support this, the UK, Scottish and Welsh governments are each providing NFM support and policy direction. For example the Department for Environment, Food and Rural Affairs (Defra) has invested £15 million into NFM schemes, while environmental agencies across the three countries have worked with the Environment Agency (EA) to publish the Working with Natural Processes to Reduce Flood Risk directory. This brings together NFM research, analysis, case studies and evidence. Meanwhile, the UK government’s 25-year Environment Plan includes a national approach that will incentivise farmers to manage their land in a way that protects and enhances the environment, including using natural flood management.
However, uptake of NFM schemes can be perceived as too costly and time consuming with too few benefits to deliver on a large scale. So, what needs to happen to encourage more investment in NFM? We offer our views on the step changes that we think are needed across the industry to increase uptake.
Build the business case
Evidence suggests NFM can play an important role in certain flooding scenarios such as managing smaller-scale frequent floods and building resilience to future climate change. However, many flood risk authorities look for tangible evidence of how many homes and businesses flood alleviation schemes will protect. When evaluating NFM, instead of just focusing on reducing the consequences of flooding to properties, we should be highlighting how NFM also contributes to the broader sustainable management of natural resources such as enhanced biodiversity in rivers and on land, the creation of more attractive landscapes and better quality water.
Through working closely with communities affected by flooding and by surveying residents and businesses it is possible to create cost-benefit evaluations of the wider knock-on effects of flooding in local areas such as the damaging impact it can have on a local economy. We have used this approach to value the wider benefits of several flood risk management schemes: in Bristol we identified over £1.7 billion potential additional local benefits stemming from a tidal flood risk management intervention, including protecting tourism and heritage assets and ensuring businesses can continue to operate. This approach could provide more tangible reasons to invest in NFM, leading to more community, economic and political support and helping more schemes get off the ground.
Promote traditional and NFM approaches together
NFM is typically seen as a way to increase a community’s flood resilience rather than offer complete protection. But it is harder to quantify the benefits of using ‘softer’ or natural resilience measures compared to more traditional hard-engineered measures such as coastal walls or flood gates: there is simply more evidence available so far to support traditional approaches.
However, we should be promoting how NFM can complement hard defences to provide both protection and resilience in the long term. The ‘York 5 Year Plan’ and ‘Slowing the Flow in the Rivers Ouse and Foss’ documents, which we developed with the EA following the devastating flooding in York in December 2015, set out both short term solutions and a long-term vision to increase flood protection and resilience to the city. The 5 Year Plan uses hard defences to protect people at immediate risk in the city centre whilst the Slowing the Flow document recommends integrating NFM measures further out in the catchment, to build flood resilience in line with the increased risk of flooding linked to climate change. Installing NFM in intervals will help spread costs across many years, and allow time to work with landowners upstream from York to develop and install NFM measures.
Identify wider benefits and issues
For NFM to work at catchment-scale, we need to understand the benefits of NFM that appeal most to communities — be it reduced flood risk, improved water quality, enhanced local biodiversity and so on — and promote them as a catalyst for community support. For example, if a community’s drinking water needs to be treated by the local water company to remove high phosphate levels, and all residents pay via their water bills for that to happen, we would work with the water company to deliver NFM measures that manage flooding in ways that also tackle the phosphate issue and reduce the overall cost to the public purse. Our award winning Ecosystem Services Identification, Valuation and Integration (ESIVI) tool can be used to quickly identify various benefits provided by a scheme’s natural capital and the potential to enhance existing services or create new ones, and estimate their monetary value.
Sophisticated benefits mapping can help identify ‘flagship’ issues within catchments. Working with Natural Resources Wales in the Elwy and Clwyd river catchments in North Wales, we used aerial imagery, ordnance survey (OS) mapping, habitat and geomorphology classification and flood risk information to map the best places to apply NFM measures and identify potential wider social and environmental benefits that would come from them.
NFM in action: restoring Swindale Beck
The Swindale valley is on the eastern side of the Lake District National Park. Over one hundred years ago, the Swindale Beck — which runs through the valley — was straightened to create extra farmland. The straightened river caused water to rapidly shoot downstream, increasing the risk of flooding, while also having a negative impact on wildlife.
We worked alongside the landowner United Utilities, RSPB, the EA and Natural England to restore a stretch of Swindale Beck to its natural meandering path, extending the length of the river to help slow the flow of water through the valley to reduce flood risk.
By working with natural processes, we’ve created multiple benefits on one of the largest upland river and floodplain naturalisation projects in the UK. The new meandering channel reinstates habitats for fish and insects, and almost immediately after the works were complete salmon spawned in the river. Planting of native tree species will become homes for wildlife, while a rich variety of new plant species will flourish from the natural flooding regime.
The project demonstrates how, with close collaboration with landowners, NFM schemes can deliver multiple benefits for the greater public good beyond flood resilience, and do so without disturbing existing farming activities and other land uses.
Image credit: RSPB images