In the second of two roundtable debates devoted to water resilience, the subject turned to drainage, wastewater and the impact of flooding. The discussion featured near- and long-term solutions, changing roles and responsibilities, the ongoing role of the regulator and the growing importance of data.
Awareness and accountability
To properly address the water waste challenge, roundtable attendees argued that it was important first to revisit roles and responsibilities. From an industry perspective, there needs greater recognition that drainage is not a water company responsibility alone. “If you look at the reasons rivers are not achieving good ecological status… you’ll see that the water sector is [partly] responsible… but so is agriculture, road runoff and housing”. Therefore, before investing in more storm tanks, for example, those responsible must first ensure sustainable drainage exists in the appropriate farming, highway or residential setting.
Meanwhile, greater awareness is required among householders. Despite the fact that six million properties in England are at risk of flooding, many homeowners remain oblivious to the risks. New flood performance certificates might help focus minds but what is needed is a comprehensive programme of education and awareness to underscore the importance of personal responsibility.
Role of the regulator
Most attendees agreed that it was time to change the way the water industry is overseen. Most shared the view expressed in a government white paper that the “current domestic legislative framework for water is … complex and not always well-aligned with modern expectations or emerging pressures”. One attendee characterised existing regulation as “sticky… like a layer of treacle”.
However, while the government’s stated “direction of travel” for future regulation—including parallel tracks for water and waste—was met with broad agreement, some attendees pointed to a lack of detail that could put “practical implementation” in jeopardy. Clarity is an urgent requirement: “You can’t regulate complexity but you can make sure that… roles and impacts are clear, and that [any] solution is coordinated”.
SuDs law
Those in search of near-term solutions should look to sustainable drainage systems (SuDS). Designed to reduce flood risks, improve water quality and manage surface water runoff, SuDS-based initiatives are appearing in “pockets” across the country. In Mansfield, home of the UK’s largest flood resilience scheme, a £76m SuDS programme features rain gardens and bioswales (landscaped, vegetated trenches). These measures are designed to create 30m litres of surface water storage and reduce flood risks for 90,000 people.
Mansfield was selected for its unique soil and its relatively isolated boundary, characteristics not necessarily replicable elsewhere. The project does, nevertheless, demonstrate what’s possible. Elsewhere, the London Borough of Enfield has embarked on a smaller-scale SuDs programme that will see 125 small interventions in the next two-to-three years.
More broadly, £11bn is earmarked to be spent in England over the next five years on improving an estimated 2,500 storm overflows, while nearly £5bn is being invested in upgrades at wastewater treatment works to remove phosphorus, a cause of nutrient pollution.
Local innovation
“Small interventions at scale”. This was a phrase repeated several times during the roundtable and it reflected a conviction that relatively minor schemes can have a major impact when replicated across locations and over time. Whether this approach necessitates, or prefigures, centralised mitigation efforts is open to debate. Some believe it might. “We can now model the whole water cycle… We can rewire the system”. Others suggested, however, that a lack of collective will, funding and common policy imperatives persists, making integration more difficult to achieve. “We’re failing because we are not looking at the key interdependencies”.
Access to data
In the further pursuit of solutions, attendees called for improved access to, and use of, data. While pockets of high-quality information—to monitor sources of pollution, for example—exists, access to good intelligence is mostly “sparse”. Without complete datasets on the overall quality of water in rivers, it is easy to draw the wrong conclusions. If you don’t know, for example, the impact of a spill on the physical behaviour of a “full flowing” river system, actions may be misplaced and money misspent. Why? Because “not all spills are bad spills”.
In a similar case of misplaced assumptions, one attendee urged that policymakers and public to revisit resilience investment. Rather than see it as a “cost centre”, we should view it as an “economic multiplier” where “every pound spent on resilience today would avoid multiple pounds in the future. [It would also avoid] pollution, fines, reputational damage and lost productivity”.
Drainage and Wastewater Resilience, a roundtable jointly hosted by Prospect and Southern Water, took place on 11th February 2026
This paper brings together the key insights from our discussion at a pivotal moment for wastewater resilience. While there has been recent progress, the underlying challenge remains stark and cannot be addressed through incremental change alone.
The latest data is a reminder of both scale of the challenge and system fragility. In 2025, around 291,000 storm overflow discharges were recorded, lasting close to 1.9m hours. Although this represents a reduction on the previous year, it is partly driven by favourable weather conditions and does not reflect a sustained structural shift. Spill levels remain far above what regulators consider acceptable, reinforcing the need for continued and accelerated action.
At the same time, pressures on the system are intensifying. Ageing infrastructure, much of it operating close to capacity, is being stretched further by climate change, urbanisation and rising environmental expectations. These arenot isolated challenges, they are compounding and systemic, with growing implications for communities, rivers and long-term service resilience.
The clearest conclusion from our discussion is that recent approaches are no longer sufficient. Wastewater resilience cannot be delivered through isolated asset upgrades or reactive interventions. It demands a fundamental shift towards whole-system thinking, earlier intervention, and far stronger alignment across policy, regulation and delivery.
This is not simply a question of doing more, it is about doing things differently. The prize is a wastewater system that is more resilient, more integrated, and better able to meet the expectations of customers, communities and the environment over the long term.
Chris Offer
Strategy and regulation director, Southern Water
