Richmond SuDS requirements and drainage proforma
How to complete Richmond’s SuDS submission, from the London proforma and runoff target to maintenance and exceedance.
The short version
Richmond asks for a completed London SuDS Proforma with every planning application. Submit it with a SuDS statement, the supporting plans and calculations, and details of who will maintain the system.
- Planning trigger
- SuDS and a proforma with every application
- Runoff objective
- Greenfield rate wherever feasible
- Fallback minimum
- At least 50% peak-rate attenuation
Use this as a starting point. Check the current validation list and the particular flood and drainage constraints on your site before submitting.
Start by confirming what the council asks for and which flood-risk tests apply to the site. Then use the document list and technical checks to set the scope. Further down, we look at the drainage conditions and refusal reasons found in the borough's decision notices.
When is a drainage strategy or FRA needed?
| Project situation | What to do | Status |
|---|---|---|
| Any planning application | Complete the London SuDS Proforma and submit a statement describing the proposed system and its maintenance. | Required |
| Any development proposal | Use SuDS suited to the scale of the proposal and follow the London drainage hierarchy. | Required |
| Greenfield runoff cannot be achieved | Demonstrate why and provide at least 50% attenuation of the pre-development peak runoff rate. | Required |
| Site affected by flood risk | Check whether a flood risk assessment and additional resilience evidence are required. | Check for this site |
| Infiltration or external discharge proposed | Provide the ground or connection evidence needed to support the proposed discharge route. | Usually required |
What to send with the application
Prepare these first
- Completed London SuDS Proforma and a SuDS statement
- Existing and proposed site and drainage layouts
- Runoff-rate and storage calculations referenced by the proforma
- Exceedance routes and long-term ownership, management and maintenance information
Add these if relevant
- Flood risk assessment where national or site-specific triggers apply
- Infiltration, groundwater or connection evidence supporting the proposed discharge route
- Landscape, water-quality and biodiversity evidence needed to demonstrate the selected SuDS
What the drawings and calculations need to show
Submit the proforma and drainage evidence together
Cross-reference the proforma to the calculations, site layout, drainage design, exceedance routes, landscape proposals and maintenance information.
Aim for greenfield runoff
Design toward greenfield runoff rates. If that cannot be achieved, demonstrate why and provide at least 50% attenuation of the pre-development peak runoff rate.
Test the critical storm
Demonstrate performance for the 1-in-100-year rainfall event with the appropriate climate-change allowance and show where exceedance flows will go.
Secure long-term performance
Identify who owns, inspects and maintains each component, with tasks and frequencies appropriate to the proposed SuDS.
Small extension with a new patio
A householder proposal adds roof and hard-surfaced area even though it is not a major development.
- Complete Richmond’s London SuDS Proforma because the borough applies it to every planning application.
- Show the before-and-after impermeable area and how runoff is managed through the drainage hierarchy.
- Cross-reference the proforma to the layout, calculations and exceedance information.
- State who will look after each measure and what maintenance it needs.
This example shows how the submission might be assembled. It is not a drainage design. The final scope depends on the site and the proposal.
Official forms and guidance
- Richmond Council: sustainable drainage systems
- Richmond Council: London SuDS Proforma
- GOV.UK: when a flood risk assessment is required
- GOV.UK: national standards for sustainable drainage systems
These links were checked 3 September 2026. Forms and validation requirements do change, so check the council website again before issuing the application.
Observed planning-condition data
What the drainage conditions actually ask for
The theme breakdown appears once enough drainage-conditioned approvals have been read to report it reliably.
Allow for discharge before agreeing a start date
There are not yet enough records to publish a reliable borough figure. Check the exact wording on the permission before agreeing the programme.
- Copy the condition into a schedule and list the evidence that answers each clause.
- Check that the calculations, drawings, specifications and maintenance plan use the same assumptions and references.
- For a pre-commencement condition, secure the written discharge before starting any work covered by the restriction.
- Where the condition asks for verification, keep site photographs, installation records and as-built information.
Understand the programme effect of a pre-commencement condition .
Reasons drainage submissions are refused
We have not read enough refusals in Richmond upon Thames to publish a useful local breakdown. The London-wide analysis is available for wider context.
Projects attracting these conditions
There are not yet enough records to publish a reliable project-type breakdown.
About the data
The observed figures are computed from the planning decision notices from Richmond upon Thames and are recalculated as we read more. We do not publish a rate when its sample is too small. This is not a complete record of every decision made by the authority, and it cannot tell you whether a document will be accepted for a particular site. Only aggregate figures appear here. See the full methodology or the London-wide picture.
Working in another borough? Compare drainage conditions and refusal patterns across London, then look at the individual schemes and project teams behind the figures.
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