Flood Risk and Drainage: Navigating a Tighter Regulatory Landscape

This article was written by Antony Riozzi, Director of Water Services at Arbtech

confirms that water management is no longer a bolt-on regulatory issue; it is a fundamental development viability concern.

The policy direction is clear: the market is moving towards a statutory requirement for integrated water management, and the risk of owning an obsolete asset that cannot effectively manage surface water is rapidly increasing.

---

Antony Riozzi - Arbtech

Flood risk and drainage have become central considerations for every stage of development planning in the UK, and the regulatory landscape around them is tightening. With updated national standards, stronger planning policy, and the growing expectation for sustainable drainage systems (SuDS) across all developments, early engagement on water management is now critical for developers.

For years, developers sought out land considered naturally unconstrained sites where flood risk and drainage were not major limiting factors.

However, that land is becoming harder to find.

Urban expansion, denser development, and ageing drainage networks mean that even previously “safe” sites can now pose complex surface water challenges. At the same time, climate change is intensifying rainfall patterns and increasing the likelihood of flooding, placing greater pressure on local infrastructure and planning authorities to ensure new schemes are resilient.

In response, the planning framework is evolving.

The National Planning Policy Framework (NPPF) was updated in late 2024, expanding the expectation for SuDS beyond major developments to all sites where drainage has an impact.

This aligns with the Government’s new non-statutory technical standards for SuDS, published in June 2025, which set out detailed design principles for surface water management, runoff destinations and climate change allowances. While currently guidance, these standards are already shaping planning decisions and are expected to form the basis of future statutory requirements.

Meanwhile, the Environment Agency has refreshed its Flood Map for Planning and standing advice for flood risk assessments, both of which now place greater emphasis on surface water flooding and system exceedance, risks that are increasingly relevant even outside traditional flood zones. Together, these changes reflect a consistent policy direction: flood risk and drainage must be addressed earlier, more comprehensively, and to higher technical standards than ever before.

For developers, this shift presents both challenges and opportunities. The risk of delay or redesign grows if flood and drainage issues are not identified until late in the planning process.

Conversely, schemes that engage early with Lead Local Flood Authorities (LLFAs), drainage engineers and the Environment Agency are better placed to create integrated, policy-compliant solutions.

Designing SuDS at concept stage, incorporating swales, attenuation basins, permeable paving and natural flood management, can reduce runoff, provide net gains for biodiversity and strengthen the planning case.

Importantly, well-designed SuDS also add long-term value. Developments that manage water visibly and effectively are more resilient, easier to maintain and often more attractive to investors and occupiers.

As the government moves closer to enacting a statutory approval regime for SuDS under Schedule 3 of the Flood and Water Management Act 2010, early adoption of best practice will place developers ahead of the curve.

The Insider Take

The opportunity for developers is to treat early water engagement as a strategic asset class.

By integrating SuDS at the concept stage, developers not only mitigate project risk and avoid costly redesigns but also create resilient, desirable schemes that are inherently more valuable and attractive to investors.

Early adoption of this strategic approach is the key to future-proofing the development pipeline and de-risking capital allocation.