The Flood Map for Planning includes several layers of information, which includes data created to support the use of Flood Zones in the planning process. These datasets show the extent of land at risk of flooding to a defined annual exceedance probability (AEP) or chance of flooding each year, taking into account the possible effects of climate change (detailed below).

These datasets include the following scenarios:

● Undefended: 0.1% AEP (1 in 1000) Rivers/Sea ● Undefended: 1% AEP (1 in 100) Rivers/ 0.5% AEP (1 in 200) Sea ● Defended: 0.1% AEP (1 in 1000) Rivers/Sea ● Defended: 1% AEP (1 in 100) Rivers/ 0.5% AEP (1 in 200) Sea

The undefended products show flood extents that ignore the presence and condition of flood defences.

The defended products take into account the presence of flood defences and assume that they operate in the way they were intended (or designed) to function. This does not include any asset failure (or removal) scenarios.

Climate change scenarios have been produced to indicate the possible impacts of climate change on future risk. The climate change allowances are based on the latest UK Climate Projections (UKCP18) from the Met Office, using the Representative Concentration Pathway (RCP) 8.5. The specific climate change scenarios shown are as follows:

● the ‘Central’ allowance for the 2080s epoch (2070-2125) for risk of flooding from rivers
● the ‘Upper End’ allowance for risk of flooding from the sea, accounting for cumulative sea level rise to 2125

For climate change scenarios, it is assumed that existing flood defences continue to function in the same way as present day. No allowance is made for any future changes to flood defence design or operation.

These datasets are designed to only give an indication of flood risk to an area of land and are not suitable for showing whether an individual property is at risk of flooding. This is because we cannot know all the details about each property.

Information on flood depth, speed or volume of flow is not included.

OPW FRS Benefiting Areas. Published by Office of Public Works. Available under the license Creative Commons Attribution 4.0 (CC-BY-4.0).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)....

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).

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. 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. 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).