How high can a storm surge be?

In England, storm surges typically raise sea levels by 1-2 metres. The 2013 North Sea surge raised levels by up to 2.7 metres in some locations.

Is coastal flooding getting worse?

Yes. Sea level rise and potentially more intense storms due to climate change mean coastal flooding is expected to become more frequent and severe.

What is managed realignment?

Managed realignment involves deliberately moving sea defences inland, allowing low-lying land to flood naturally. This creates saltmarsh habitat and reduces pressure on defences.

Coastal Flooding Explained — Complete Guide

How Coastal Flooding Happens

Coastal flooding occurs when the sea level temporarily rises above normal, overtopping or breaching sea defences.

Key Causes

Storm surges: Low atmospheric pressure and strong winds push sea levels up by 1-2 metres or more
High tides: Spring tides are naturally higher; combined with a surge, they create extreme levels
Wave overtopping: Large waves crash over sea walls
Sea level rise: Long-term climate change is raising average sea levels
Coastal erosion: Weakened coastline is more vulnerable

Most At-Risk Areas

The east coast (North Sea surge corridor)
The Severn Estuary (tidal range of up to 14 metres)
The Humber Estuary
Low-lying areas behind sea defences
Reclaimed land (the Fens, Romney Marsh, Somerset Levels)

The 1953 North Sea Flood

The UK's worst coastal flood killed 307 people and led to the creation of the modern flood warning system and the Thames Barrier.

Sea Level Rise

Sea levels around England are rising by about 3-4mm per year. The EA's climate change allowances add up to 1.2 metres to design flood levels for coastal developments.

Coastal Defences

England has about 3,000 km of coastal flood defences including sea walls, embankments, groynes, and managed realignment areas.