Natural Resources Wales (NRW): Its Role in Flood Risk and Planning

Natural Resources Wales (NRW) is the public body that manages flood risk from rivers, the sea and reservoirs in Wales, and the organisation a local planning authority must consult when a development site sits in a flood zone. It does the flood job the Environment Agency does in England. It does not decide planning applications, but an NRW objection weighs heavily with the council that does. If your site is in Flood Zone 2 or 3 on the Flood Map for Planning, NRW will read your Flood Consequences Assessment and tell the council whether the risk is acceptable.

This guide covers what NRW is, what it does on flooding, exactly when it is consulted on a planning application, what its response means for your scheme, and how its role differs from the lead local flood authority and the SuDS Approving Body.

NRW responded to around 2,100 planning consultations on flood risk in 2024/25, and more than 1,000 of those sites were in Zone C2, the undefended floodplain category then in use.

What is Natural Resources Wales?

Natural Resources Wales is a Welsh Government sponsored body, formed on 1^st April 2013 when Environment Agency Wales, the Countryside Council for Wales and Forestry Commission Wales were merged into one organisation. As Wales's main environmental regulator and adviser, it covers flood risk, water quality, forestry, protected sites, waste and industrial permits under one roof.

That single-body model is the main structural difference from England, where the same work is split between the Environment Agency, Natural England and the Forestry Commission. For a developer the practical effect is one consultee: the same NRW planning response can cover flood risk, protected species, contaminated land and discharges to a river.

On flooding specifically, NRW is a risk management authority under the Flood and Water Management Act 2010. It works to the Welsh Government's national flood strategy and uses the planning policy set out in Technical Advice Note 15 (TAN15).

NRW manages more than 3,900 flood risk management assets in Wales, including around 455 km of raised defences.

Is there an Environment Agency in Wales?

No. The Environment Agency covers England only. Environment Agency Wales stopped existing in 2013, when its functions passed to NRW, so the answer to "does the Environment Agency cover Wales?" has been no for more than a decade. Search results still turn up the old name, and English guidance refers to the Environment Agency throughout, which is how Welsh applications end up quoting the wrong regime.

The differences go further than the name on the consultation response. Welsh flood policy, mapping and drainage law all diverge from the English versions:

For the equivalent split of responsibilities on the English side, see the explainer on who is responsible for managing flood risk in England.

What does NRW do on flood risk?

NRW's flood work covers five things: mapping, warnings, defences, regulation and planning advice. The figures below come from its flood risk management annual report for 2024 to 2025, the most recent full year published.

• Flood mapping. NRW produces the Flood Map for Planning, the public Flood Risk Assessment Wales map and the detailed models behind them.
• Flood warnings. It runs the Welsh flood warning service: 622 flood alerts, 217 flood warnings and two severe flood warnings in 2024/25, with more than 48,000 properties registered.
• Defences and maintenance. It inspects and maintains defences on main rivers and the coast, completing 14,289 routine asset inspections in the year.
• Permits. It issues Flood Risk Activity Permits for work in, over or near a main river or sea defence: 204 were issued in 2024/25, and 56 enforcement cases were closed.
• Reservoirs. It enforces the Reservoirs Act 1975 in Wales, the main safeguard against reservoir flooding, covering 405 registered large raised reservoirs.

The same report records NRW removing 18 posts from its flood risk structure, with nine more to go in 2025/26, which matters to applicants because consultation responses now come from a smaller team at the same time as the 2025 TAN15 widens the range of applications that need an FCA.

More than 274,000 properties in Wales are at risk of flooding from rivers, the sea or surface water, according to NRW's 2024/25 figures.

Who handles flood risk in Wales?

NRW deals with main rivers, the sea and large reservoirs. Surface water, groundwater and ordinary watercourses belong to the county or county borough council acting as lead local flood authority, which is also the SuDS Approving Body. The council's planning department decides the application, and the water company handles the public sewers.

The split is easiest to see on a real flood. In February 2020 Storm Dennis sent the River Taff to its highest levels since records began, with NRW recording peak flows of around 900 tonnes of water a second, according to its five-year review of the February 2020 floods.

Rhondda Cynon Taf Council's Section 19 report for Upper Boat and Nantgarw found 306 properties flooded, 121 homes and 185 non-residential. The main cause was the Taff overtopping, which is NRW's responsibility; its Upper Boat gauge peaked at 5.49 m. But the Cross Keys culvert on the Nant Garw, an ordinary watercourse, was also hydraulically overloaded, contributing to flooding at 24 properties on Cardiff Road, and surface water on the highway flooded two further homes; both of those sources belong to the council. Working out which authority owned which source, after the event, is what a Section 19 flood investigation is for. A few kilometres down the valley, Gwaelod-y-Garth flooded in July 2026 after a blast at Taff's Well Quarry, a quarry flood risk that no Flood Map for Planning layer covers.

A Flood Consequences Assessment has to deal with every source that affects the site, whichever authority owns it. An FCA that satisfies NRW on the river but ignores an undersized culvert upstream can still draw an objection from the council as lead local flood authority.

When is NRW consulted on a planning application?

NRW is a statutory consultee on flood risk. Schedule 4 of the Town and Country Planning (Development Management Procedure) (Wales) Order 2012 requires the planning authority to consult it on development in Flood Zone 2, Flood Zone 3 or a TAN15 Defended Zone for rivers and the sea. NRW's own guidance narrows that slightly:

Three rules settle the borderline cases:

• Householder applications. Extensions and outbuildings in Zones 2 and 3 are not sent to NRW, but the council still expects a proportionate FCA and applies TAN15 itself.
• Greenfield highly vulnerable development in Zone 3. Housing on undeveloped land in Zone 3 is not referred because TAN15 restricts it so heavily. If the council is still minded to approve it, the Welsh Ministers must be notified.
• Development near defences and riverbanks. NRW is also consulted on development within 8 m of a flood defence or riverbank, within 16 m of a sea defence, and on works in or next to a watercourse, whatever the flood zone. Work on a smaller stream may also need ordinary watercourse consent from the council.

Statutory consultees in Wales have 21 days to give a substantive response under article 15A of the procedure order, and they must report their performance to the Welsh Government every year. A substantive response can say NRW has no comment, has no objection, has concerns that can be addressed, or objects with reasons.

NRW's 2024/25 advice was still given under the 2004 TAN15 and its Development Advice Map, which is why its annual report counts consultations in Zone C2 rather than in the new flood zones. From 31^st March 2025 the same sites are screened against the Flood Map for Planning. Because the new zones build in climate change, some land that sat outside Zone C2 now falls inside Zone 2 or 3.

What happens after NRW responds?

An NRW response is advice to the planning authority, not a decision. What it does to your application depends on which of four answers comes back:

1. No objection. The council can determine the application on flood risk, sometimes with NRW's standing advice attached.
2. No objection subject to conditions. NRW asks for conditions such as minimum finished floor levels, flood resilient construction or a flood warning and evacuation plan. These carry through to the decision notice and have to be discharged before or during construction.
3. Concerns that can be addressed. Typically the FCA is missing a climate change scenario, the model has not been checked against NRW's flood model checklist, or safe access has not been shown. The applicant has to supply more information before a decision.
4. Objection. NRW considers the risk unacceptable or not properly assessed. The council can still approve, but it has to give clear reasons for departing from its specialist adviser, and NRW can ask the Welsh Ministers to call the application in.

An unresolved NRW objection leaves the council choosing between refusal and a decision against its specialist adviser, with a call-in request as NRW's next step.

The Welsh Government's guidance on the Flood Risk Area Development Notification (Wales) Direction 2025 adds another step for the highest-risk cases. Where a council does not intend to refuse highly vulnerable development, or a net increase in homes, on undeveloped land in Zone 3, it must notify the Welsh Ministers and wait 21 days from their acknowledgement before granting permission. That adds weeks to the programme even when everything else is agreed, and it exposes the scheme to a call-in and a decision taken out of the council's hands.

Where an objection turns on the evidence, such as a missing climate change allowance, an outdated model or no assessment of the extreme event, the gap is fixable before submission. It is much harder to fix once the council has an objection on file and the determination clock is running. An objection can also be a symptom of a site that is simply in the wrong place, which is a question for Strategic Flood Risk Assessments and site selection, not for mitigation.

NRW's two flood maps

NRW publishes two flood maps and only one of them counts in planning. The Flood Map for Planning is the official basis for TAN15 decisions. The Flood Risk Assessment Wales (FRAW) map is the public "check your flood risk" service, and NRW is explicit that it has no status for planning. An FCA built on the FRAW map starts on the wrong evidence base.

Zone thresholds, the map layers, what the map leaves out and how to check a site step by step are covered in the guide to the Flood Map for Planning Wales and its flood zones. Where the zones look wrong, NRW will review a new model through its flood map challenge process.

How the 2025 TAN15 changed NRW's advice

The revised TAN15 came into force on 31^st March 2025, replacing the 2004 TAN15 and the 1998 TAN14 on coastal erosion. Applications made before that date stay under the old version. For NRW's advice the main changes are:

• One map. The Flood Map for Planning replaced the Development Advice Map as the basis for every flood risk decision.
• Defended Zones. Land behind defences built to at least a 1 in 100 year river standard or 1 in 200 year sea standard is shown separately. It still needs an FCA, because defences can be overtopped or fail.
• Acceptability criteria. The old justification test gave way to acceptability criteria covering the design flood, the extreme flood, flood risk elsewhere and residual risk.
• Wider FCA triggers. More types of application now need an FCA than under the 2004 version.
• Coastal erosion. Erosion risk moved into planning policy for the first time.

The detail sits in the articles on the new TAN15 2025 policy update and TAN15 and development in Wales, with the Welsh Government's written statement on the publication of TAN15 setting out the official position. For a planning-stage view of what the policy asks for on a given site, see the TAN15 flood risk planning guidance.

SuDS in Wales: NRW's role versus the SuDS Approving Body

NRW does not approve drainage. Since 7^th January 2019, new developments of more than one dwelling, or with a construction area of 100 m² or more, have needed separate approval from the council acting as SuDS Approving Body before construction starts, as the Senedd Research briefing on the mandatory SuDS requirements explains.

NRW still has a say. Paragraph 11 of Schedule 3 requires the SAB to consult it where a drainage system discharges, directly or indirectly, into a watercourse. A Welsh scheme can therefore need NRW's view twice: on flood risk through planning, and on the outfall through the SAB. Designing the surface water drainage strategy and the FCA together avoids a site layout that works for one consent and fails the other.

Getting NRW advice before you apply

NRW offers two routes before an application goes in, set out on its page about its service to developers, and has one firm expectation of any FCA built on a model:

• Free preliminary opinion. An indicative view of which environmental topics, flood risk among them, a scheme needs to address, within 21 calendar days.
• Discretionary advice service. Detailed, chargeable advice at £125 an hour plus VAT, with at least 30 days to allow before work starts.
• Model review. Where an FCA relies on flood modelling, NRW expects its flood model checklist to be completed and submitted with the model, as set out in its guidance on modelling for Flood Consequence Assessments.

Paid advice is worth considering on complex sites, such as a Defended Zone, a site next to a main river or anything needing new hydraulic modelling. On a straightforward site, a well-evidenced FCA submitted with the application usually does the same job for less. NRW also publishes general advice for building in flood risk areas.

Flood risk in Wales is rising on NRW's own projections: by 2120 sea flooding is expected to put nearly 40,000 more properties at risk and river flooding more than 24,000. Schemes such as the managed retreat at Clydach Terrace and the £85m Welsh flood investment show both ends of the response. For a new development the practical point is earlier: settle the flood zone, the Defended Zone status and the drainage outfall before the layout is fixed, and commission the Flood Consequences Assessment for planning in Wales while there is still room to change it.

Frequently asked questions