How flooding increases CO2 and what we can do about it – 2021 Flood Expo
11th October, 2021

Price & Myers Associate, Mark Gordon recently attended the 2021 Flood Expo in Birmingham, a major flood management event for the UK. Here, Mark shares some highlights from his visit.

Flood Expo is the UK’s largest flood exhibition and hosts an impressive roster of flood professionals, innovators, and suppliers. These collaborators contributed to an excellent programme of seminars and talks running over two days in September.

One of the event's main themes marking the event was the drive towards greater sustainability, and the role more innovative and intelligent drainage systems have to play in helping designers tackle the Climate Emergency.

One speaker in particular caught my attention. John Alexander from AquoBex outlined the real-world impact flooding has on the environment. A startling statistic shared during his presentation was that, on average, a flooded property contributes nearly four tons of carbon emissions annually, much of which is energy used to dry out materials and property. Waste disposed to landfill from flood affected homes is also equivalent to the total annual residual household waste from a typical household in one year. The effect of flooding on the environment is a big, and underappreciated factor.

Could the use of more sustainable materials like aluminium, which can be recycled infinitely, be used in flood-resilient construction to reduce the impact of flooding on the climate? A reduction in flood damaged materials being discarded to landfill would also have obvious environmental benefits. It’s time we invested more resources in prevention rather than recovery.

It was also good to see SuDS (Sustainable Drainage Systems) evolving to be more dynamic and agile. The use of “intelligent attenuation systems” is now an important feature in the design of surface water attenuation systems, and it’s used by key players in the market such as Wavin, Polpipe and SDS. Their attenuation systems are linked to live Met Office data. This means they assess future weather forecasts, along with expected rainfall. This allows these systems to respond accordingly by emptying storage tanks and other SUDS systems before the storm event, creating enough storage for projected rainfall volumes. This enables designers like me to specify more efficient attenuation systems and also reduce flood risk by lowering the chances of overwhelmed drainage systems, which ultimately contribute to overland flood flows.

When these systems are linked to rainwater harvesting systems, which recycle water for non-potable uses such as toilet flushing, we have the power to mitigate the impact of increased rainfall intensities. It will be exciting to see how these intelligent systems develop and how they integrate on a local, regional, and even national scale.

I also learned of a new drive by the Forestry Commission and the Environment Agency to try and address the increased risk of flooding from rivers, at their source. This new initiative involves the planting of new woodlands along rivers to help manage flood risks, and boost water quality and wildlife. The “Woodlands for Water” project is being piloted in six regions initially and will use trees to slow down flood water from overtopped banks. An additional benefit of the project is improved water quality in these networks.

The National Trust’s Director of Land and Nature, Harry Bowell, recently spoke about the initiative and outlined the intended benefits: "With 90% of UK floodplains 'not fit for purpose' and creating flood issues for communities, we fully recognise the value of trees to our river corridors in helping to slow flood waters, soak up carbon and keep rivers cool in the face of rising temperatures”.

It’s encouraging to see a more sustainable and organic solution to increased flood risk being implemented, one which will hopefully reap rewards as the new woodlands flourish.

Attending the Expo was time well spent, and will have an impact on how everyone in the Civil Engineering team at Price & Myers designs for flood risk. For an extended view on how we approach designing and managing for flood risk at our practice, don’t miss my colleagues’ Dimitris Lindartos and Andy Toohey discussing the subject here.