Introduction
For much of the southern half of the UK, it has been a damp start to the year.
The opening months of 2026 have been exceptionally wet across the UK. A strong and unusually southerly jet stream has steered a succession of low-pressure systems towards us, bringing frequent rain, strong winds and flooding.
So, with the UK getting more used to this ‘new normal’ of wet winters, what does it mean for the planning system both in a proactive development sense, and also for those seeking permission to build flood defences?
Is the recent weather exceptional?
The Met Office reports: Cornwall and County Down recorded their wettest January on record, while Northern Ireland saw its wettest January in 149 years. Across the UK, 26 stations set new monthly records for highest January rainfall. Daily records also fell: Plymouth recorded its wettest January day in 104 years, Hurn (Dorset) in 74 years and Dunkeswell (Devon) in 57 years. Each of these figures helps to demonstrate that 2026 has started not just wetter than average, but with rainfall intensities and frequencies that rival some of the most notable periods in the observing record.
Climate projections indicate that on average, winters will continue to become wetter and summers drier, though natural variability will mean we will continue to see individual years that don’t follow this trend.
However, rain that does fall in summer will likely be more intense than what we currently experience. For example, rainfall from an event that typically occurs once every 2 years in summer is expected to increase by around 25%. This will impact on the frequency and severity of surface water flooding, particularly in urban areas.
If these predictions are accurate, the UK will face an increasing risk from flooding across susceptible areas.
What does this mean in context of the planning system?
With an increased risk of flooding, the planning system will need to adapt in both a proactive and reactive sense: proactively in terms of permissions for new developments in areas that may be prone to flooding, and reactively relating to permissions for flood defence schemes where needed.
Proactive land development
The planning system needs to avoid placing people and infrastructure in vulnerable locations, as well as not allowing development that will have a knock-on effect elsewhere.
Local Planning Authorities rely on updated flood risk assessments to shape land allocations, which increasingly push growth away from high-risk zones. Where development is unavoidable, the sequential and exception tests determine whether sites can be justified and what level of mitigation is required.
With a focus on flood resilience, design expectations are also shifting. Sustainable drainage systems are now a requirement for many schemes, and developers must show how run-off will be managed within the site boundary. Measures such as raised thresholds, resilient materials and safe access routes are becoming standard in at-risk areas.
Planning conditions and legal agreements often secure maintenance and long-term drainage responsibilities, meaning early engagement with Lead Local Flood Authorities is essential.
Reactive flood defence schemes
Flood defence projects face their own challenges in the planning system, ironically for some, because building on a floodplain is in itself a major barrier.
Although some schemes benefit from permitted development rights, many require full applications that must balance urgent protection needs with environmental and visual impacts. Full planning permission would generally be needed for a significant flood wall, land raising, or any infrastructure adjacent to a main river.
Construction of flood defences may disrupt access, alter views or change the character of riverside areas, so transparent engagement is vital. Planning must assess the benefits to those protected against any potential effects downstream.
Increasingly, schemes are expected to be adaptable, with designs that can be raised or expanded as future climate scenarios unfold. Planning conditions often secure monitoring and maintenance to ensure these structures remain effective throughout their lifespan.
What trends are we seeing?
With increasing demands from central Government to meet housing targets, Local Planning Authorities are feeling the pressure to find more and more sites.
Avoiding development on floodplains altogether is not realistic; however, we are seeing a more robust approach from developers through clearer assessments, improved flood protection schemes, and stronger mitigation and resilience measures.
The question is not whether building on a floodplain is always wrong, but whether a specific site can safely accommodate what is proposed, both now and in future climate scenarios.
Our take
“Flooding across the UK is only going to get worse. As a country, we need to become resilient, which means stronger guidance in the planning system for both proactive development and reactive defence schemes.
“We’re already seeing some positive steps being taken by developers, alongside considerations outlined in the National Planning Policy Framework (NPPF), which requires all planning decisions to address flood risk and climate adaptation.
“The Planning Practice Guidance (PPG) also gives specific instructions on assessing flood risk from all sources; applying the sequential and exception tests; designing for residual risk; incorporating sustainable drainage; and using flood resistance and resilience measures.
“Building on floodplains will continue, but applications need to demonstrate serious consideration of both the current climate and what the future is likely to hold.”
Andrew Metcalfe, Managing Director
Stay out of deep water with Squires Planning
If you’re planning a development or scheme on or close to a floodplain, it’s worth seeking expert advice at an early stage to keep you out of deep water, both metaphorically and physically!
Squires Planning and our network of experts can help you assess the viability of the scheme and advise on your best chance of planning success.
Contact us today for more information.
