On the 31st March 2025 , the Welsh Government released significant updates to flood risk policy in Wales (TAN15). Here’s a summary of the 50-page guidance distilled into 🔟 key points:
1. Development Advice Map (DAM) has been discontinued: The DAM will no longer be used alongside Planning Policy Wales (PPW) and TAN15 to guide planning applications. The new TAN15 will relate to the Flood Map for Planning (FMfP) for decision-making. All current applications within planning have an 8-week window to refer to the old TAN15 , before the requirement to move over to the new TAN15 document . All new full planning applications from the 31st March will need to refer to the new TAN15 document .
2️. TAN15 Defended Zones: Areas where flood risk management infrastructure provides a minimum standard of protection against flooding from Rivers of 1:100 (Q100), and from Tidal sources of 1:200 (T200) (plus climate change allowance and freeboard). These have now been given a specific criteria for FCAs to be judged against rather than that of the Flood Zone 2/3 .
3️. Vulnerability Classifications: Development Vulnerability Categories updated and clarified, including elaboration on ‘Water Compatible Development’;
4. A relaxation (degree of potential flexibility) of the pre-existing A1.14 (now 11.7, 11.8 & Figure 5) for redevelopment, changes of use, conversions, and extensions, where the ability to substantially redesign a development is limited. In those circumstances the thresholds are a guide; rather than prescriptive. Conversely (to the above), a tightening of the pre-existing A1.15 (now 11.2 & Figure 6) which refers to ‘Tolerable Conditions’ in a prescriptive fashion compared to an indicative one.
5. Definitions of ‘New Development’ to identify Any development on greenfield land and ‘Redevelopment’ to identify Any development on previously developed land as defined in Planning Policy Wales.
6. Justification Test Replaced: The previous Justification Test has been substituted with a more flexible plan-led approach to decision-making.
7. More onus and emphasis on SuDS, specifically; synergy between Flood Risk and Drainage including FCAs and SAB Applications in support of planning; New Flood Zones for Surface Water and Small Watercourses have been added, and an FCA is needed for any development in these areas (Even only partly).
8. As a pre-requisite to proposing any development in Defended Zones , Local Planning Authorities must understand fully the quality and condition of existing flood defences and the level of protection, they afford both now and in the future. These will be provided within a future SFCA / Preliminary Flood Consequences Assessments or be provided by data requests
9. Greenfield sites can provide important flood attenuation opportunities and can store and manage water in the event of flooding; they should not be built on unless they are replaced by suitable alternative sites which clearly contribute to flood management enhancement. No new highly vulnerable development on greenfield land should be permitted in zone 3 regardless of the conclusion of any Flood Consequences Assessments and NRW will not consider these conclusions. Welsh Ministers must be notified of any such proposal a planning authority intends to approve.
10. The Welsh Government will monitor the effectiveness of PPW and TAN15 through a Notification Direction. The Notification Direction ensures the Welsh Government is made aware of planning applications for new highly vulnerable development in Zone 3 – Rivers and Sea, which the planning authority is minded approving. Welsh Ministers will have the option of calling-in the application to determine themselves.
