From ageing infrastructure to changing climate patterns, the need for advancements in the way we design spaces is clear. In 2025, we saw both extended periods of hot, dry weather leading to restrictions on water usage and intense periods of rainfall causing flash flooding in many areas. The UK already has the tools, evidence and emerging delivery models needed to adopt sponge city principles, but implementation remains too fragmented, too slow and too dependent on isolated projects.
For the flood and water management sector, the challenge is no longer whether blue-green infrastructure, sustainable drainage systems and nature-based solutions can reduce surface water flood risk. That case has been made. The more pressing question is how the UK moves from pilot schemes and planning aspirations to catchment-scale delivery, long-term asset stewardship and measurable resilience outcomes.
The sponge city concept provides a useful framework because it reframes urban rainfall as a resource to be absorbed, stored, slowed, cleaned and reused, rather than a problem to be conveyed away as quickly as possible. It also helps bring together disciplines that too often operate in silos: flood risk management, drainage engineering, planning, highways, landscape architecture, water company investment, biodiversity and public health.
This is where the UK has a real opportunity. The 2025 white paper Creating Sponge Cities to Tackle Surface Water Flooding highlights international best practice, including Copenhagen’s Cloudburst Management Plan, where surface water management has been planned as a citywide system rather than a collection of disconnected interventions. More than 250 surface water projects, over 125 new pipes and six stormwater tunnels have been brought together to manage extreme rainfall through both grey and blue-green infrastructure.
But the most compelling examples for UK practitioners are closer to home.
The Mansfield Sustainable Flood Resilience project is perhaps the clearest current demonstration of sponge city principles being applied at scale in a British context. Severn Trent’s £76 million Green Recovery project is delivering hundreds of interventions across the town, including detention basins, bioswales, rain gardens, permeable paving, street planters and bioretention tree pits. The ambition is not simply to beautify the urban realm, but to reduce surface water flood risk for around 90,000 people and create capacity to store approximately 30 million litres of stormwater during heavy rainfall.
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That distinction matters. Sponge city infrastructure must not be treated as amenity-led landscaping with drainage benefits attached. Done properly, it is flood infrastructure. It requires hydraulic modelling, robust design standards, appropriate adoption routes, inspection regimes, maintenance funding and clear accountability over the lifetime of the asset.
Other UK places are also beginning to show what this transition could look like. London has long recognised the value of sustainable drainage and urban greening in reducing pressure on combined sewer systems. Wales has taken a stronger regulatory route, with mandatory SuDS approval for new developments. Across England, local authorities and water companies are increasingly exploring partnership models that can unlock wider benefits from surface water interventions, from reduced sewer flooding to improved water quality and biodiversity gain.
The next step is to make these approaches normal, not notable.
That means accelerating the implementation of Schedule 3 of the Flood and Water Management Act in England, so sustainable drainage becomes a consistent requirement for new development rather than a variable planning outcome. It means ensuring highways schemes and public realm investments are designed to manage water at source and it provides local authorities the resources and technical capacity to plan, approve, adopt and maintain blue-green assets with confidence.
It also means improving how schemes are valued. Traditional cost-benefit assessments can struggle to capture the full contribution of sponge city measures: avoided flood damage, reduced sewer overload, lower treatment costs, urban cooling, carbon sequestration, biodiversity, amenity, health and place-making. For industry experts, this is not a peripheral issue. If appraisal methods undervalue multi-functional infrastructure, investment decisions will continue to favour single-purpose grey solutions, even where blended approaches would deliver greater long-term resilience.
For BluWater Solutions, the message is clear. The UK does not need to wait for a perfect model before scaling up sponge city delivery. The building blocks are already visible in Mansfield and other emerging schemes. What is needed now is greater coordination, stronger policy alignment, reliable maintenance models and a shared commitment to designing places that manage rainfall where it lands.
Surface water flooding is a system problem. It will not be solved by isolated assets, short-term funding pots or end-of-pipe thinking. Sponge cities offer a practical route to more resilient urban catchments, but only if the concept is treated as core infrastructure strategy.
The UK has spent decades designing water out of towns and cities as quickly as possible. The next phase of flood resilience must be about designing water back in - intelligently, safely and at scale.
This article appeared in Issue 12 of Flood Industry magazine, May/June 2026. You can view it here.