Preparation of Flood Maps

Predictive flood hazard and risk maps were prepared for each AFA, to identify and map the existing and potential future risk from flooding in these areas.

The detailed work required to prepare the flood maps involved engineering analysis of the river systems, estuaries and coastal areas, including their hydrology and involving detailed hydraulic modelling. The work and analysis was informed by extensive consultation, including with elected representatives, State Agencies, representative organisations, stakeholders and members of the public.

The OPW has assessed and mapped the flood extents, hazard and risk for a range of flood events from frequent, minor flood events up to very rare, extreme events.

Flood maps developed through the OPW’s CFRAM Programme include Flood Hazard Maps that describe the characteristics of each predicted flood scenario, such as the land areas prone to flooding, its projected depth and level, and the calculated flow and velocity (speed) of the floodwater.

Flood Hazard Maps help assess the potential impacts of possible future floods, which are presented on the Flood Risk Maps that describe these impacts on people, the community, the economy and the environment.

Maps for some AFAs were developed outside of the CFRAM Programme through parallel projects.

The flood mapping process is important to inform the identification and development of feasible flood risk solutions, and also to inform Local Authorities in relation to planning and development management, and also planning by State Agencies and individuals for emergency response to a flood event.