The Great Stour Project - River and Coastal Flooding

Coastal Protection

Following the 1953 coastal flooding sea defences were improved. They were tested by a severe storm in 1978 and, although much damage was effected on the coastal towns, only one person was killed and the widespread inundation of 1953 was avoided.

In East Kent, coastal protection works are required for two reasons: to protect the coastline from erosion and to prevent further invasions of the sea.

Defences fall into two main categories, hard defences and soft defences. Hard defences are man-made rigid structures, such as sea walls and breakwaters, usually constucted in concrete and steel. Soft defences are made of unconsolidated material such as sand or shingle such as the beach between Reculver and Minnis Bay which has been stabilised by groyning.

At Coldharbour (TR267692), between Reculver and Minnis Bay, both hard and soft defences combine to protect a particularly vulnerable area of the coast. A photograph taken in 1953 shows the former clay embankment, which protected the low lying Wantsum Marshes, breached by the sea with extensive submergence of the lowland. The present sea wall is a sturdy concrete structure which is itself protected by a shingle ridge which is maintained by the local authority. On the seaward side of the ridge is a narrow beach, held in place by groynes. The photograph above, taken from TR267692 in February 2000, shows both defensive structures and the small lagoon trapped between. The towers at Reculver can be seen on the horizon.

Another view of the sea wall from a location near Plumpudding Island (TR270693) shows a narrow shingle beach, held in place by substantial rock groynes. Without the beach, the sea wall would come under direct attack by the sea which would eventually undermine and destroy it.

The threat of flooding from Pegwell Bay, at the eastern end of the Wantsum channel, is much less. The bay is sheltered from northerly winds by the Isle of Thanet and the fetch from the south east is limited by the presence of the Goodwin Sands a few kilometres offshore. Into this sheltered, low energy environment, the River Stour carries its sediment load, adding to material transported by coastal processes. The result is an extensive area of deposition and salt marsh development.

The ancient cinque port of Sandwich is at risk from flooding by the River Stour and by high tides. Although much of the old town is several metres above the flood plain, properties alongside the river are subject to occasional  inundation. The most likely scenario for serious flooding is the coincidence of a high fluvial discharge meeting a strong tidal flow upstream.

On 19 December 1999, high tides caused the Stour to overtop its banks in the town though there was, in this case, no significant damage to property. The photograph shows the state of the river at the time of the highest tide, looking toward the quay from the northern side of the tollbridge. Downstream of Sandwich, the river was contained between artificial levees constructed to protect the coastal lowlands.

Between the estuary of the Stour and the White Cliffs of Dover, the coastal levels are protected by sea walls and shingle ridges, maintained by the Dover District Council. To the south of Deal there is a wide shingle storm beach with a crest height 4.5 metres above the high water mark and extending over 90 metres inland.