Natural flood management and sustainable drainage systems can support the same project, but they answer different design questions. Agree the flood problem, study area, evidence and long-term responsibilities before choosing measures.
What is natural flood management?
Natural flood management (NFM) works with natural processes to slow or store water across catchments, floodplains and coastal areas. Measures can involve soil, woodland, rivers and runoff. The Environment Agency identifies potential wider benefits for habitats and water quality. However, an attractive landscape proposal needs evidence before the team credits it with a particular flood-risk benefit.
Start with the problem you need to solve. Is it runoff generated by the development, flooding arriving from a wider catchment, or both? Next, identify the people and land needed to deliver the response. A feature outside the application boundary may require a different agreement and delivery programme.
Natural flood management, SuDS and the flood risk assessment
Use the following briefing comparison to allocate work. It is an original coordination aid, rather than a design standard or a test of planning acceptability.
| Task | Question to resolve | Briefing output |
|---|---|---|
| Natural flood management | Can working with the wider landscape contribute to managing the identified flood problem? | Study boundary, options, evidence gaps, land partners and responsibilities. |
| Site SuDS and drainage | How will the development manage its surface water? | Coordinated drainage proposals, design assumptions and maintenance arrangements. |
| Flood risk assessment | What flood risks affect the proposal, and what evidence does the planning decision require? | Assessment scope, source data, conclusions and mitigation evidence. |
For the planning route, read when a flood risk assessment is required. Our drainage strategy and SuDS comparison explains the site-document distinction. Keep those assessments connected to the actual proposal.
Build an evidence brief before selecting measures
First, ask the flood-risk specialist to describe the mechanism, affected receptors and relevant study area. Then record the available terrain, watercourse, drainage and land-use information. Identify missing evidence and who will obtain it.
Next, distinguish an option from a demonstrated result. Record which benefits rely on further survey, modelling or agreement. Ask the specialist to explain the limitations and the consequences if a preferred measure cannot proceed.
The Environment Agency’s Working with Natural Processes evidence resources provide a starting point for understanding measures and knowledge gaps. Their research landing page directs readers to updated 2024 outputs. Use the appropriate current evidence for the location and mechanism; a published case study elsewhere does not establish the performance of your site.
- Define the flood mechanism and decision being supported.
- Identify the study boundary and affected land interests.
- Record the source, date and limitations of each dataset.
- Agree how benefits and possible adverse effects will be assessed.
- Keep unresolved assumptions visible in the options register.
Agree ownership, maintenance and fallback arrangements
A measure needs a responsible owner throughout its life. Therefore, discuss access, inspection, repair, funding and reporting while comparing options. Record who can authorise changes and what happens when land ownership or the site layout changes.
Also ask how the team will check that delivery matches the assessed proposal. Drawings, specifications and management information should refer to the same measures. Where habitat objectives are involved, reconcile them with the drainage information and specialist ecological advice.
Use our SuDS maintenance and handover guide for the site drainage interface. The habitat and drainage coordination checklist helps authors keep shared drawings consistent.
A fictional coordination example
A developer considers upstream woodland measures alongside a site drainage strategy. The team records the woodland option separately, identifies the land agreement and specialist evidence still needed, and retains a clear drainage design brief. It does not replace an established design assumption with an unverified benefit.
Questions to settle at the next design meeting
Does natural flood management replace SuDS?
Do not assume that it does. Ask the relevant specialist to identify which problem each measure addresses and how the evidence supports the combined proposal.
Does an NFM proposal remove the need for an FRA?
Check the planning assessment requirements for the actual site. An options proposal does not itself demonstrate that the required assessment has been completed.
What should the project coordinator request first?
Request a scoped problem statement, an evidence register and a responsibility schedule. These allow the specialists to identify what must be resolved before design decisions depend on a measure.
References and scope
England programme and planning context. This article provides an original briefing framework. It does not size measures, predict flood reductions or confirm funding eligibility.
- Environment Agency and Defra. Programme guidance. Published 22 September 2023; updated 30 October 2026. Definition and current programme status.
- Environment Agency. Working with natural processes to reduce flood risk. Research landing page published 24 February 2021, covering the 2017 project and linking to updated 2024 resources.
Start with the flood problem and the decision
Discuss your project brief with ACP. Share the location, proposal, planning stage and available flood or drainage information.