Flooding is an escalating threat to many Irish towns, and Enniscorthy in County Wexford is no exception. Nestled along the River Slaney, the town has a long history of flood events impacting residents, businesses, and infrastructure.
Mallon colleague Michael Foley has created the following maps to show how advances in Remote Sensing and Earth Observation technologies are transforming how we understand, predict, and manage flood risks.
Understanding Flood Risks in Enniscorthy
One of the most recent and severe flood incidents in Enniscorthy’s history occurred on Christmas Day 2021, when over 90mm of rain fell in less than 24 hours. The river burst its banks, inundating homes and roads, damaging bridges, and severing key transport links in County Wexford.
A recent flood risk assessment for Enniscorthy made use of high–resolution LiDAR–derived Digital Surface Models (DSM) and Digital Terrain Models (DTM), provided by Ireland’s Office of Public Works (OPW). These datasets offer detailed 3D representations of the landscape, with the DTM mapping the bare earth surface and the DSM capturing above–ground features such as buildings and vegetation.
To assess the town’s exposure to potential flooding, building footprint data from OpenStreetMap were combined with these LiDAR datasets. The analysis simulated flood extents by incrementally increasing water levels in 0.5 metre steps. Each scenario was overlaid on the building footprints to determine precisely which properties would be affected at each stage.
This incremental approach provides critical insights. By visualising the progressive encroachment of floodwaters, planners can identify the areas at most significant risk under both moderate and extreme flood scenarios. The findings also help emergency services and local authorities to prioritise response strategies, implement targeted flood defences, and explore long–term adaptation measures, including strategic retreat where necessary.
The integration of LiDAR–derived elevation models with open–source mapping data highlights how remote sensing can deliver both cost–effective and highly actionable intelligence for flood resilience planning. For towns like Enniscorthy, this is more than a technical exercise; it’s a lifeline. The 2021 floods underscored how quickly extreme weather can overwhelm existing defences, disrupt daily life, and leave lasting scars on communities.
As climate change continues to drive more frequent and severe flooding, harnessing EO technologies will be essential in equipping Irish communities with the knowledge and tools they need to protect lives, livelihoods, and the local environment.
