Schedule 3 SuDS approval and what commencement means

Schedule 3 SuDS approval would add a second consent to almost every development in England. A drainage system would need approval from a SuDS Approving Body before construction starts, that approval would become a precondition of connecting surface water to the public sewer, and national standards for sustainable drainage would stop being advisory. Schedule 3 to the Flood and Water Management Act 2010 has been on the statute book since 2010 and is still not in force in England, so the position remains one to verify rather than plan around.

Anyone drafting a drainage strategy today works within the existing arrangement: planning conditions, the lead local flood authority as consultee, and the right to connect intact. What follows is what would change, and why it is worth building programme flexibility now.

What Schedule 3 provides for

The Schedule does four things.

It requires drainage systems for new development to be approved by a SuDS Approving Body before construction begins. It provides for national standards for sustainable drainage design, construction, maintenance and operation, with which approved systems must comply. It makes the right to connect surface water drainage to the public sewer conditional on that approval. And it provides for the approving body to adopt and maintain approved systems serving more than one property, with the funding that implies.

Each of those is a structural change rather than a tweak. The last one in particular moves long-term maintenance from developers and management companies onto a public body, which is the reason the regime has been so slow to arrive.

The approving body and what it would approve

The SuDS Approving Body would be the unitary or county authority, in most cases the same organisation that already acts as lead local flood authority. In practice that means the drainage team that currently comments on planning applications would instead determine a separate application.

The difference matters. A consultation response is advice the planning authority weighs. An approval is a consent you cannot build without, with its own application, its own fee, its own determination period and its own appeal route.

The level of detail also shifts. A drainage strategy submitted with a planning application is usually a design in principle: outfall, discharge rate, storage volume, indicative layout. An approval application would need construction-level detail, because the body granting it is committing to adopt and maintain what gets built.

The end of the automatic right to connect

Section 106 of the Water Industry Act 1991 currently gives a right to connect drains and sewers, including surface water, to the public system. Schedule 3 would qualify that right for surface water, making connection conditional on SuDS approval.

That is the provision with the sharpest practical edge. At present a developer who cannot agree a sustainable drainage solution still has a route to the sewer, subject to the undertaker's limited grounds of objection. Under Schedule 3 the approving body becomes the gatekeeper, and a refusal would stop the scheme rather than merely complicate it.

It also changes the negotiating position on discharge rates. Authorities that currently ask for greenfield run-off rates through a planning condition would be asking through a consent that cannot be worked around.

National standards becoming statutory

Sustainable drainage design in England currently runs on the non-statutory technical standards published in 2015, the guidance in the Planning Practice Guidance on flood risk and coastal change, and industry practice built on the CIRIA SuDS manual. Local authorities add their own requirements through local plan policy and supplementary guidance, which is why standards vary noticeably between neighbouring authorities.

Statutory national standards would flatten much of that variation. Designers would gain certainty about what is required and lose the ability to argue that a local standard goes beyond national policy.

Labelled as devolved content: Wales implemented Schedule 3 from 7 January 2019, so SuDS approving bodies and statutory national standards already operate there, with thresholds that catch small developments as well as large ones. Welsh applications need the Welsh standards and Planning Policy Wales checked directly, and English practice does not transfer.

Where commencement stands

Schedule 3 is not in force in England. Government has consulted on implementation and has indicated an intention to bring the regime into effect, with questions outstanding about thresholds, exemptions, the treatment of small sites and the funding of adoption.

Commencement would come through a statutory instrument, not an announcement, so check legislation.gov.uk for the commencement position rather than relying on a press notice or a conference slide. Reform of this kind has a long history of slipping, and the sensible planning assumption is that the current arrangements continue until an instrument says otherwise. Follow it through the planning law updates timeline, and treat the pattern as similar to other staged commencements such as the April 2024 biodiversity commencement for small sites.

What developers do in the meantime

Four things, none of which are wasted if commencement never happens.

1. Design to adoptable standards where the system will serve more than one property, because retro-fitting adoptability into an approved layout is far harder than building it in.
2. Fix the maintenance arrangement early. Name the body responsible, the funding mechanism and the duration, and put it in the drainage strategy rather than leaving it to a section 106 negotiation.
3. Engage the lead local flood authority before the layout is fixed. They are a statutory consultee on major development for surface water, and their position on discharge rates and infiltration testing will not soften after validation.
4. Keep the infiltration testing and the ground investigation current. Test results more than a couple of years old get challenged, and repeating them in winter is slower than it sounds.

The other point is programme. If Schedule 3 arrives mid-scheme, transitional provisions will matter enormously, and a project with permission but no construction start is the one most exposed.

How drainage strategies would need to change

The practical consequence for a Drainage Strategy is that it becomes two documents: a planning-stage strategy demonstrating the principle, and an approval submission carrying the detail. Writing the first with the second in mind is free. Writing it without is how schemes lose three months between permission and start on site.

One honest uncertainty. Nobody outside government knows the thresholds, and whether small sites are caught changes the significance of this reform enormously for anyone building fewer than ten homes. The Welsh approach catches very small developments, and if England follows it the effect on minor applications would be considerable.

Constraint-driven requirements rarely arrive alone, and drainage sits alongside other catchment-level rules such as those explained in the note on where nutrient neutrality requirements come from.

To see which drainage and flood documents a site is likely to need under the rules in force now, enter your postcode on PlanScope and answer the guided questions.

This is general guidance, not legal advice, so check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.