Chapter 14 Flood Risk Management

14.0 Introduction 
 

Flooding is a natural phenomenon of the hydrological cycle. It constitutes a temporary covering of land by water and presents a risk only when people and human assets are present in the area which floods. Flooding can happen at any time in a wide variety of locations. Different types of flooding include overland flows, river flooding, coastal flooding, groundwater flooding, estuarial flooding and flooding resulting from the failure of infrastructure. Rivers with a low gradient are more susceptible to flooding at any time of the year; however, the increasing tendency for heavy summer downpours can also cause significant flooding in steep, flashy catchments.  

Flooding can pollute water and cause significant damage to human life, the local economy, local biodiversity and local public health. Like any other natural process, flooding cannot be completely eliminated, but its impacts can be avoided or minimised with proactive and environmentally sustainable management and planning.
 
Projections for climate change include continued sea level rise, potentially more severe Atlantic storms, which could generate more significant storm surges and extreme waves, increase in the number of heavy rainfall days each year, and wetter winters. The potential impacts from these projections include increasing flood risk for communities and infrastructure along rivers, estuaries and the coast with accelerating rates of coastal erosion; threatening coastal habitats and environment. 

Climate change will impact on different aspects of the national flood risk management programme. These impacts, and the need to take adaptive action to address them, vary across the different programmes of work within flood risk management, with the highest priority impacts being on flood protection, spatial planning and development management. Non-structural flood risk management measures (e.g., preparedness measures) tend to be more inherently adaptable to changes in flood frequency and severity, and ‘green’ measures, such as natural water retention measures also facilitate adaptation while providing benefits to other sectors (e.g., improve water quality and biodiversity, contribute towards carbon mitigation).

With reference to the National, Regional and County Objectives set out in Chapter 2 of this plan, ensuring that flood risk is appropriately managed will contribute to numerous goals across the three pillars of ‘sustainable healthy communities’, ‘climate action’ and ‘economic opportunity’ including: 

-    Reduction and management of flood risk;
-    To build resilience to increased risks of extreme weather events, changes in sea level and patterns of coastal erosion to protect property, critical infrastructure and food security;
-    To conserve and enhance biodiversity, protected habitats and species;
-    To identify, protect and enhance Green Infrastructure and ecosystem services and promote the sustainable management of strategic natural assets such as coastlines, farmlands, peatlands, uplands woodlands and wetlands;
-    Promoting environmentally sustainable development in terms of location, layout, design and energy and water usage.

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