Lewes, East Sussex, UK
Creating a new riverside development alongside a community with living memory of catastrophic flooding demands particular sensitivity. In Lewes we are working with innovative developer Human Nature to design a highly sustainable neighbourhood with future-proofed flood defences and an explicit remit to ensure it does not increase flood risk in other parts of the town.
Since disastrous flooding hit the town of Lewes in 2000, local residents and businesses have lived in fear of it happening again. So proposals to redevelop an old industrial site on the floodplain of the tidal River Ouse unsurprisingly raised questions of what impact it might have on flooding risk.
The former Phoenix Industrial Estate was under 1.5 m of water in the 2000 flooding, and the site has a history of failed redevelopment proposals. Human Nature – an unconventional real estate company founded by two former directors of Greenpeace and with a focus on projects with exemplar sustainability and place-making credentials – has taken a fresh approach to creating a feasible and sustainable scheme.
The masterplan foresees a mixed-use neighbourhood with some of the site’s industrial buildings retained and reused, and access the riverfront opened up. .
Expedition was tasked with designing the flood defences, sustainable drainage, water strategy and related earthworks; we have also advised on the re-use of existing structures across the site and the potential to integrate new buildings with the upgraded flood defences.
The site’s existing flood defences vary widely in size and condition. The big challenge is to bring tidal and fluvial flood resilience to the masterplan; protecting the site while also improving and mitigating flood risk for the neighbouring area. We are working closely with the Environment Agency to achieve this.
Our design has to work on several levels – not simply to provide flood defences but also improve the connectivity to the riverfront as part of the landscape strategy, contribute to enhancing biodiversity, whilst considering the phasing of construction. Future resilience is a real concern as climate change will increase rainfall intensities and fluvial flood risk, as well as sea levelsand tidal flood risk.
We are proposing a combination of flood defence walls sensitively integrated with planting and retained parts of the existing river wall and its character; landscape features on the site to manage run-off and remove pollutants before discharge, and integrated storage features so stormwater can be retained until river levels drop sufficiently to allow its release by gravity.
Render and drawing courtesy of Periscope