National infrastructure (NI) forms the backbone of our modern communities and provides the foundations for economic productivity and social wellbeing. NI includes the five economic infrastructure sectors of: (1) energy, (2) transport, (3) water, (4) waste, and (5) information and communication technology (ICT). These five systems are interdependent, relying on the service provided by each other to function normally. They support and underpin our communities by providing the energy and resources needed to function and enable people, information and goods to move efficiently. However, in the UK as well as other advanced nations, NI is continually threatened by natural disasters, man-made accidents and malicious attacks. These threats have the potential to damage our NI systems, which can result in devastating effects to the communities which rely upon them. For example, hurricane Katrina (2005) flooded 80% of New Orleans causing ‘unprecedented damage’ to the electricity system and ‘devastating’ communications infrastructure which incapacitated emergency service dispatch centres. Several large hospitals were also destroyed, the majority of health care facilities were closed and hundreds of patients became stranded inside dark and flooded hospitals that lacked basic supplies – some of these patients succumbed to these conditions before they could be evacuated. Fortunately, such large scale natural hazards are extremely rare in the UK; however, smaller scale events can still have devastating consequences. For example, the summer 2007 floods in England flooded approximately 55,000 homes and businesses and left half a million people without mains water or electricity. To better protect our communities and the people within them from the effects of a natural hazard we must ensure that our NI systems are resilient to these risks. To achieve this, we must first gain an understanding of the risks and their potential impacts to our vital NI systems.

To identify the risks to the UK, the government developed the first National Risk Register (NRR) in 2008, which was ‘intended to capture the range of emergencies that might have a major impact on all, or significant parts of, the UK’. This report identified hazards that were likely to affect the UK over the next 5 years and gave an assessment of the relative likelihood and impact of each hazard. This report has been reviewed and updated in recent years (initially in 2012and again in 2013) to reflect the changing threat from risk to the UK.