Abstract: The Office of Public Works (OPW) is responsible for leading and co-ordinating the implementation of localised flood relief schemes to provide flood protection for cities, towns and villages, either directly or in association with relevant Local Authorities. This data outlines the areas benefiting from such flood relief schemes, the date of completion, the design standard and any human intervention that is required. A Benefitting Area is defined as the area that benefits from the implementation of the measures within an Option or Scheme, including improvements to conveyance such as channel widening or deepening, and culvert upgrades.

The OPW has an agreed Memorandum of Understanding (MOU) with Insurance Ireland, the representative body for insurance companies in Ireland. The MOU has a specific focus on agreeing the basis on which information can be provided to the insurance industry on areas benefitting from flood relief schemes completed by the OPW. Under the terms of the MOU, Insurance Ireland requires the OPW to provide it with data on OPW completed flood defence schemes which shows the design, extent and nature of the protections offered by these works. The OPW requires that insurers, who are party to the agreement, take full account of the information provided by the OPW when assessing exposure to flood risk for private dwellings and small businesses.

Lineage: Fluvial and coastal flood maps are developed using hydrodynamic modelling, based on calculated design river flows and extreme sea levels, surveyed channel cross-sections, in-bank / bank-side / coastal structures, Digital Terrain Models, and other relevant datasets (e.g. land use, data on past floods for model calibration, etc.). Typically, these models are run as undefended and defended scenarios to establish the areas defended or benefitting from a Flood Relief Scheme. However, the process may vary for particular schemes or maps and the Technical Hydrology and Hydraulics Reports for each Flood Relief Scheme sets out further technical details on the derivation of the flood maps and associated data.

June 2025 Clare River (Claregalway) Flood Relief Scheme data added.

Purpose: The data has been developed to inform the implementation of Flood Relief Schemes (FRS) to provide flood protection for cities, towns and villages and to describe the FRS characteristics and benefits. This includes a planned programme of prioritised, feasible works in accordance with the National Flood Risk Policy (2004) and to achieve the objectives of the Flood Risk Management Plans developed under the European Communities (Assessment and Management of Flood Risks) Regulations 2010 to 2015 (the “Regulations”) (implementing Directive 2007/60/EC).