The Government has announced it will make sustainable drainage systems mandatory to new developments in England – the new approach to sustainable drainage is set to reduce flood risk and clean up rivers. 

In order to achieve better rainwater management, the government committed to publishing the review and decision regarding implementation of Schedule 3 to the Flood and Water Management Act 2010 as part of its Storm Overflow Discharge Reduction Plan, published last year.

Recommendations regarding Sustainable Drainage Systems (SuDS) were first set out in Sir Michael Pitt's review of the summer 2007 floods published in June 2008 which assessed SuDS as an effective way to reduce the risk of surface water flooding as well as the burden on the piped sewerage system.  The Pitt review rrecomendations were subsequently included in Schedule 3 to the Flood and Water Management Act, which gained Royal Assent in April 2010.

In England, Schedule 3 was not commenced, as the government addressed increasing the use of SuDS through planning policy from April 2015.

In October 2019 the Government commissioned an independent review of the arrangements for determining responsibility for surface water and drainage assets. The review, which was carried out by David Jenkins, set out clearly why the Government should reconsider implementing Schedule 3 to the Flood and Water Management Act 2010. The government response was published in July 2021 and it committed to review the case for implementation.

In addition to requirements that SuDS should be given priority in new developments in flood risk areas, current planning policy requires that SuDS are included in all new major developments (developments over 10 homes), unless there is clear evidence that this would be inappropriate. 

The Jenkins review of the arrangements for determining responsibility for surface water and drainage assets published in August 2020 suggested the planning-led approach alone is not working. David Jenkins recommended that non-statutory technical standards for sustainable drainage systems should be made statutory as the ambiguity makes the role of the planning authority very difficult.

The review also found that in general there were no specific checking regimes in place to ensure that SuDS had been constructed as agreed, leaving concerns about unsatisfactory standards of design and construction, and of difficulties of ensuring proper maintenance once the developer has left the site.

The recommendation to make SuDS mandatory to new developments in England is the result of the Government’s review which has been published today. This will reduce the risk of surface water flooding, pollution and help alleviate the pressures on traditional drainage and sewerage systems.

The Government's review states:

"The findings of this review including from risk management practitioners and many others evidence a widely held perception that existing planning and building regulation control provide insufficient focus on how rainwater can best and most sustainably be managed in new developments.

"Therefore, this review does not support the option of continuing to deliver SuDS purely through the planning process. Neither do the findings support an alternative approving and adopting body to the unitary authorities or county councils."

Announcing the outcome of the review, Environment Minister Rebecca Pow said: 

“Our traditional drainage systems are under increasing pressure from the effects of climate change, urbanisation and a growing population. 

“The benefits of sustainable drainage systems are many – from mitigating flood risk by catching and storing surplus water and reducing storm overflow discharges, to enhancing local nature in the heart of our developments and helping with harvesting valuable rain water.

“Taking a more consistent and effective approach to sustainable drainage systems will improve the resilience of our drainage and sewer infrastructure, while reaping these broader benefits.”

Schedule 3 provides a framework for the approval and adoption of drainage systems, a sustainable drainage system approving body within unitary and county councils, and national standards on the design, construction, operation, and maintenance of sustainable drainage systems for the lifetime of the development.

It also makes the right to connect surface water runoff to public sewers conditional upon the drainage system being approved before any construction work can start. 

New developments can inadvertently add to surface and sewer flood risk by covering permeable surfaces like grassland and soil that would otherwise assist in dealing with heavy rainfall. 

Water UK - Government must also implement policy recommendations from Storm Overflows Taskforce

A Water UK spokesperson said:

“This is a welcome step forward and something the industry has been pushing Government to implement for some time. However, this is only one of several vital policy changes recommended by the Government’s Storm Overflows Taskforce to accelerate the improvement of overflows. Alongside the £56 billion of new investment from water companies, Government must implement all of the taskforce’s recommendations if we are to truly transform the health of our water environment.”

The new approach to drainage will ensure sustainable drainage systems are designed to reduce the impact of rainfall on new developments by using features such as soakaways, grassed areas, permeable surfaces and wetlands. This reduces the overall amount of water that ends up in the sewers and storm overflow discharges. Certain features such as tanks and water butts also allow for water reuse and reduce pressures on water resources.

Following today’s publication of the review, regulations and processes for the creation of sustainable drainage systems at new developments will now be devised, through the implementation of Schedule 3 to the Flood and Water Management Act 2010.

The Government will now give consideration to how Schedule 3 will be implemented, subject to final decisions on scope, threshold and process, while also being mindful of the cumulative impact of new regulatory burdens on the development sector. 

This will include a public consultation later this year, which will collect views on the impact assessment, national standards and statutory instruments. 

Feedback from the consultation will help to shape a new consistent approach to sustainable drainage systems with implementation expected during 2024.

There will be exemptions for smaller developments, with thresholds being determined through the upcoming consultation period.

EAC Chair says right that Government leaves no stone unturned to address major and complex challenge of easing pressure on the system

Commenting on the announcement, Environmental Audit Committee Chairman, Rt Hon Philip Dunne MP, said:

“Our drains and sewers are spilling under significant pressure, exacerbated by new housing developments having the automatic right to connect to the sewerage system. It is absolutely right that the Government leaves no stone unturned to address the major and complex challenge of easing pressure on the system.

“Its intent for new developments to include sustainable drainage systems is absolutely the right direction, and was a key recommendation in our report that considered water quality. Developers must not simply have the right to connect to an overloaded sewerage system and not contribute to improvements.”

Wales has already implemented Schedule 3 - the Flood and Water Management Act 2010 (Schedule 3) came into effect in Wales on 7 January 2019 and requires new developments to include Sustainable Drainage Systems (SuDS) features that comply with national standards. 

The review has not addressed the subject of retro-fitting SuDS in existing developments where the only change to the development is the drainage system. The Government says this will present a completely different challenge and is also outside of the powers of Schedule 3.

Introducing the Government's review report and recommendations, Environment Minister Thérèse Coffey MP said she intends “to make swift progress in its implementation.”

Professor Jim Hall, National Infrastructure Commissioner, said: 

“Last month the Commission recommended Schedule 3 was implemented in England without delay, as the first of a number of recommendations for addressing the growing risks of surface water flooding. Making sustainable systems the default for new developments and introducing a more consistent approach to design will help address the problem at source. It makes both economic and environmental sense and, while we await further details and the outcome of the forthcoming consultation, this is undoubtedly a positive move which we hope can be brought into practice as soon as possible.”

Click here to download  The review for implementation of Schedule 3 to The Flood and Water Management Act 2010