With extreme weather events becoming more frequent and intense, the risk of flooding has risen, necessitating effective measures to protect public safety and property.

The Welsh Government estimates that 245,000 properties in Wales are at risk of flooding from rivers, the sea, and surface water, with an additional 400 properties potentially affected by coastal erosion.

Responsibility for managing flooding incidents in Cardiff is shared among three agencies: Cardiff Council, Natural Resources Wales, and Welsh Water, depending on the source of the flooding.

Cardiff Council handles ordinary watercourses, surface water, groundwater, and highway flooding.

Natural Resources Wales is responsible for main rivers, coastal flooding, and reservoirs, while Welsh Water manages foul, surface water, and combined sewers.

The new strategy focuses on clear objectives, measures, and action plans to ensure an effective response to any flooding incident in Cardiff.

The objectives align with those set by the Welsh Government and outline ambitions, targets, and outcomes for flood risk management.

Measures are grouped into three main categories:

·       Development, Regeneration and Policy;

·       Precautions, Protection and Response; and

·       Community, Stakeholder and Collaboration.

The Action Plans include thirty-six separate responses to potential flooding incidents, whether citywide, on Flat Holm Island, or along the River Ely, River Rumney, or River Taff.

Cllr Dan De’Ath, Cabinet Member for Strategic Planning, Climate Change, and Transport, emphasized the importance of collaboration: “As we have been designated as the Lead Local Flood Authority, our role is to produce a strategy which creates an effective collaboration between the agencies that are responsible for flooding across the city.

“The flood risk areas have been assessed, and we have set out clear objectives, roles, responsibilities, measures, and action plans to manage the various scenarios, setting out effective mitigations where possible.

“The increased risk of flooding in Cardiff is due to climate change, so we are continuing our work to reduce the carbon impact of the city through our One Planet Strategy.

“In March 2019, Cardiff Council declared a climate emergency and set out the steps that need to be taken to become a net zero council. While this work continues, we are also enhancing the city’s green spaces as well as carrying out a significant upgrade to the city’s flood defences on the River Rumney. This will manage the flood risk to 1,116 residential, 72 non-residential properties and Rover Way traveller site. The new coastal defence in this part of the city will provide defence against a one-in-200-year severe weather event, including allowing for the effects of climate change.

“The Cardiff Bay Barrage which become operational in 2001 is an asset to support reducing the risk of flooding in the south of the city if tidal conditions allow. The water levels in Cardiff Bay can be lowered when bad weather is expected, to allow the additional water from rainfall to flow down from the River Taff and River Ely into the Bay. Effective maintenance of the Cardiff Bay Barrage is critical to reduce this flood risk, so further assessments and funding will be required to ensure this happens.

“The new strategy will ensure that the three agencies work together to take the necessary actions when flooding incidents occur. Risk profiling and mitigation measures are explained in detail to ensure that any response to a flooding incident is proportionate and effective, while reducing risk and building resilience where possible to manage levels of rainfall that are expected in the future. 

In conclusion, the new strategy aims to ensure that Cardiff Council, Natural Resources Wales, and Welsh Water work together to take necessary actions during flooding incidents. Detailed risk profiling and mitigation measures will ensure that responses are proportionate and effective, building resilience to manage future rainfall levels.

“By working together, the city will be better equipped to handle potential flooding incidents, ensuring public safety and property protection,” added Cllr De’Ath

Cardiff Council’s Cabinet will meet on May 15^th to consider the recommendations contained in the report, and a webcast of that meeting will be available to watch on the day here https://cardiff.public-i.tv/core/portal/home

Prior to the Cabinet meeting, the report with be scrutinised by the Environmental Scrutiny Committee on May 8^th at 4.30pm. A recording of that meeting will be available to view here Environmental Scrutiny Committee - Thursday 8 May 2025, 4:30pm - Cardiff Council Webcasting (public-i.tv)