Planning and flood risk
Planning Applications and Flood Risk, published in February 2025, outlines that 61 out of 5,848 approved residential applications throughout Northern Ireland in 2023/2024 are within an area of fluvial and/or tidal flood risk.
Decisions on residential planning applications and flooding risk are assessed under the Strategic Planning Policy Statement (SPPS) and Planning Policy Statement 15: Planning and Flood Risk (PPS15). Reasons applications within flood risk areas were approved include:
• it is an ‘exception’ under SPPS and PPS15, such as the replacement of an existing building;
• it was balanced against other factors, such as restoration of a historic listed building;
• part of the site is in a flood risk area but the dwelling itself is not; and
• a request for an FRA or drainage assessment was not made at outline planning stage when the applications was approved, later requests to revisit this cannot be granted.
Additionally, divergence between flood modelling methods used by the Department for Infrastructure’s (DfI) Rivers Directorate and FRAs, and planning authorities can result in the approval of applications within flood risk areas.
DfI tells agendaNi: “DfI welcomes the briefing paper and that it found no significant concerns with the current approach to planning consultations and flood risk in the North of Ireland.”
DfI Rivers and FRAs use detailed flood modelling, while planning authorities use strategic flood maps which are considered “less site specific and accurate”. This can lead to an application being initially rejected by a planning authority, but later approved following inspection by DFI Rivers or an FRA.
Elements of existing flood maps may also be out of date. If a challenge to DfI’s flood mapping is accepted, the Department will not update existing flood mapping “in piecemeal fashion”. The entire flood model must be updated before flood mapping can be updated. As a result, there may be applications considered within flood risk areas that have been subject to an accepted flood challenge.
The report states that implementation of FRAs and mitigation measures appear to be the developer’s responsibility, and asks who ensures these are carried out effectively. When queried on this, DfI says that DfI Rivers “expect” flood risk information to be included in planning decision notices. “However, this is ultimately a planning authority consideration,” it adds.
The report also asks if the requirements of the Reservoirs Act (Northern Ireland) 2015, which has not fully commenced, affect applications. DfI states the act will “provide a proportionate regulatory framework for the maintenance and management of controlled reservoirs”.
On insurance, the report outlines a scenario where planning is granted following detailed flood mapping, but is deemed a flood risk by an insurer using strategic mapping. When queried on this, DfI says: “DfI Rivers Directorate’s flood maps, and the process of updating these, align with industry best practice and are comparable to those in other jurisdictions.
“While insurers may use our data, they may also rely on independent sources, which can potentially lead to differing risk assessments, however this is a commercial consideration for the insurers in terms of how they operate their business.”
