Sustainable Drainage Systems

Aphra Brandreth Excerpts

Thursday 5th February 2026 Westminster Hall

[Aphra Brandreth (Chester South and Eddisbury) (Con)]

It is a pleasure to serve under your chairmanship, Mrs Barker. I congratulate the hon. Member for Newton Abbot (Martin Wrigley) on securing the debate. He spoke passionately about this issue, the impact of heavy rainfall and flooding in his constituency, and the consequences for residents when developments do not adequately address the need for sustainable drainage and for SuDS to be maintained. The hon. Member for Honiton and Sidmouth (Richard Foord) made some important points, particularly about the need for more skilled professionals in this area.

The previous Government’s plan for water, published in 2023, recognised that sustainable drainage systems are an effective means of reducing surface water flooding, and committed to their use in all new developments. The current Government are continuing that approach through the publication of national standards for sustainable drainage systems. As I understand it, although the Government are yet to make a final decision, they are pursuing a planning policy-based approach to SuDS, rather than commencing schedule 3 to the Flood and Water Management Act, which would require all developments to include SuDS in order for planning approval to be granted. If schedule 3 is implemented, developers will be required not only to include SuDS in new developments, but to ensure that designs are approved before construction begins.

As the Government’s national standards are non-statutory, the Minister will be aware that questions have been raised about enforceability. There is a concern that developers may seek to identify ways to evade the guidance. Is the Minister therefore concerned that, however well-intentioned, the non-statutory guidance may not achieve its intended purpose?

I note that although there are calls for clarity on the adoption of multi-property developments by an appropriate authority, there is no clarity about which authority that should be. Is the Minister’s Department looking at that, or would it be willing to clarify that?

I turn briefly to developments that have been built but have not yet been adopted. The Minister may be aware that research from the Home Builders Federation, published in October 2025, found that in developments of 10 or more homes built in the past three years, 97% of new sewers and 98% of SuDS remain unadopted. The research also found significant inconsistencies across local authorities. As the Minister knows, local authorities are reluctant to adopt roads until sewers are formally adopted.

I want to briefly mention two examples from my Chester South and Eddisbury constituency that illustrate the issues all too clearly. Saighton Camp, which is just outside the city of Chester, and the Wychwood estate in Wybunbury both have unadopted incomplete infrastructure. Residents have been left in limbo, with developers moving on, the water company refusing to adopt the sewerage system until the developers complete the work and the local authority refusing to adopt the road until the sewers are formally adopted. Alongside this, there are frequent issues with the swales, which are meant to provide sustainable drainage yet are ineffective. With that in mind, what assessment has the Minister made of the issue being a procedural one? Does she believe there is scope to make the adopting process more consistent to provide clarity for residents?

The Government have set a target to build 1.5 million homes in this Parliament, but given their current performance, no one really believes they can possibly achieve that. The Government’s own figures show that in their first year in power the net number of new additional dwellings and the number of new homes built both went down. Can the Minister provide assurances that the Government will not abandon their approach to SuDS, and will recognise them as a continuing priority that will not be traded off for other land uses in pursuit of their top-down housing targets? When businesses are facing increased financial pressure and costs as a result of the Government’s disastrous economic policy, what assessment has the Minister made of the effect of those policies on SuDS, which may add further costs to new homes?

On the topic of development, it would be remiss not to mention the role that farming can play in water management and sustainable drainage. Nearly 300,000 homes have been built on prime farmland, with an extra 1,400 hectares used for renewable energy projects, despite more than enough previously developed brownfield land waiting for regeneration. Under the previous Conservative Government, through the countryside stewardship scheme and sustainable farming incentives, farmers were encouraged to implement practices that would mitigate the risks and consequences of flooding. Can the Minister provide assurances that water management grants will be part of the SFI scheme when it finally reopens?

Internal drainage boards do a fantastic job of managing water levels and reducing the risk from flooding within their districts. Their work involves maintenance and improvement, and they currently play a significant part in advising on planning applications regarding SuDS. Can the Minister provide assurances that IDBs will continue to have a prominent role in the planning process? Furthermore, as the shadow Minister, my hon. Friend the Member for Keighley and Ilkley (Robbie Moore) has called for, have the Government considered the merits of bringing flexibility to the relationship between the Environment Agency, IDBs and land managers?

In 2024, the previous Government provided IDBs with £75 million to modernise and upgrade resilience assets for farms and rural communities. Is the Minister working closely with her colleagues in the Cabinet Office to monitor the consequences of the recent storms and the related funding of IDBs?

I know that all Members here today, and Members from across the country, will have constituents who are affected by flooding. We know how damaging and disruptive it can be. It is therefore important that the Government set out a clear approach as to whether SuDS are viewed as best practice or a standard approach. Clarity is needed so that the industry knows where it stands, and our constituents can have confidence in the legislation and guidance that is provided to developers. Part of that will involve ensuring a prominent role for local risk management authorities, such as IDBs, so that the best possible sustainable approaches can be implemented to mitigate the risks and consequences of flooding.