What does a SuDS planning condition actually require?
The recurring themes in drainage conditions on London approvals — and why the obligation does not end at design.
Conditions vary in wording but not much in substance. They cluster into a handful of recurring themes — and one of them lands after you have finished building.
A SuDS or drainage condition attached to a planning permission is a specific obligation, not a general instruction to drain the site properly. Reading the conditions recorded on London decision notices, they fall into a small number of repeating themes. Knowing which one you have got tells you what to submit.
What does a SuDS planning condition typically require?
The theme breakdown — attenuation and storage, discharge-rate limits, maintenance regimes, verification evidence — loads from the read notices and appears here once the sample is large enough to report.
Does the obligation end once the scheme is approved?
No. A meaningful share of conditions ask for evidence after construction — as-built drawings, verification reports, confirmation that the maintenance regime is in place.
Which changes who owns it. If a slice of your drainage conditions only close after practical completion, drainage is not a design-stage item that finishes when permission is granted — it is a handover deliverable somebody has to price, programme and actually produce. On a contract where the designer has long since demobilised, that responsibility has a habit of landing on nobody.
Are SuDS conditions mandatory on all developments?
Not universally, and there is a lot of wrong information about this online. Schedule 3 of the Flood and Water Management Act 2010 — which would have made SuDS approval a statutory requirement with its own approval body — has not been commenced in England. It is in force in Wales.
In England the requirement comes through the planning system instead: strengthened NPPF policy and non-statutory national SuDS standards, applied by lead local flood authorities, with major development broadly meaning ten or more dwellings. Several sources state that Schedule 3 is now mandatory in England. It is not — and if you are relying on a page that says so, check what else it has told you.
Where does this data come from?
Themes are bucketed from the conditions recorded on read UK planning decision notices, with each share published only when its own sample is large enough. Only aggregate figures are published — never a scheme address, an application reference, or the wording of a condition. See the methodology page, the refusal grounds , or the full London flood & drainage picture .