Coastal Flood Boundary Extreme Sea Levels (2018) - NI Extract

Extreme Sea Level values is part of Coastal Design/Extreme Sea Levels, a GIS dataset and supporting information providing design / extreme sea level and typical surge information around the coastline of the UK, including England, Wales, Scotland, Northern Ireland, Isle of Man and Jersey. The information is relevant under present day (year 2018) conditions and does not account for future changes due to climate change, such as sea level rise. This is a specialist dataset which informs on work commenced around the coast ranging from coastal flood modelling, scheme design, strategic planning and flood risk assessments.

Extreme Sea Level values describes the extreme sea levels for 16 different annual probabilities of exceedance. Confidence levels relating to the 5% and 95% lower and upper bounds of confidence are included. Mean High Water Spring (MHWS) and Highest Astronomical Tide (HAT) predicted tide levels are also included in the dataset for some sites but may not be used for navigational purposes.

This 2018 update to the Coastal Design Sea Levels dataset was carried out in partnership for the UK Coastal Flood Forecasting partnership, which includes the Environment Agency (EA), Scottish Environment Protection Agency (SEPA), Natural Resources Wales (NRW) and the Department for Infrastructure Northern Ireland (DfINI).

The main project outputs include:

• Coastal flood boundary conditions for the UK: technical summary report

• Coastal flood boundary conditions for the UK: user guide

• Coastal design sea levels – coastal flood boundary surge shapes (2018)

• GIS output in British National Grid projection

The main project outputs are available at the UK open data portal – see link below
(https://data.gov.uk/dataset/73834283-7dc4-488a-9583-a920072d9a9d/coastal-design-sea-levels-coastal-flood-boundary-extreme-sea-levels-2018)

The surge shape spreadsheet is also available at the link below (https://environment.data.gov.uk/dataset/84c97c5e-d465-11e4-afbd-f0def148f590)

This dataset is an extract from the overall UK wide project that contains GIS output covering Northern Ireland. For convenience, this GIS dataset has been re-projected to Irish Grid.