Happisburgh
COASTAL CASE STUDY
Description
Happisburgh is a small coastal village on the north Norfolk coast, faced with an eroding coastline. A local Coastal Concern Action Group (CCAG) was formed in 1999 to lobby and apply pressure on central and local government, as previous coastal defences have slowed down coastal erosion, but are now in disrepair or not coping.
Value to the nation:
- Walking: part of the England Coast Path
- Tourist area: pleasant quiet coastal village, with soft sandy beach
- Wildlife: nesting sand martins, forming burrows in the soft cliffs
- Historical: Mmanor house and iconic lighthouse
Location
Happisburgh is around six miles east of the inland market town of North Walsham. The nearest main road is the A149.
Coastal Event
The Great North Sea Flood 1953
On the night of 31 January to 1 February 1953, a major flood event caused by a combination of a high spring tide, low pressure and strong northerly winds led to a storm surge within the North Sea that affected low-lying coastal areas of eastern England, including East Anglia and the Thames Estuary. The increased volume of water overwhelmed many sea defences leading to extensive flooding, damage to property and infrastructure and loss of life. A government review took place after the event and recommended putting in place flood management policies, warning systems and improvements in coastal defences.
In December 2013 another storm surge caused the last remaining house on Beach Road in Happisburgh to teeter on the cliff edge and be so badly undermined that it had to be demolished.
Geology and the coastline
The geology at Happisburgh comprises a relatively simple, layer-cake sequence of pre-glacial sands, gravels and clays (which occur beneath the beach level) and an overlying glacial sequence comprising tills (stoney clay), laminated clays and sands. Cliff instability occurs due to topples and debris flows within the glacial sands, often exacerbated by periods of prolonged rainfall. Instability also occurs due to direct erosion by waves. To the south of the current beach access, when beach levels are low, a wave-cut platform can develop as a result of direct wave erosion of the overlying glacial clays and sands.
The pre-glacial geology has international significance as it contains archaeological evidence for the earliest humans in northern Europe and the oldest human footprints outside Africa.
GeoCoast data
Coast type
A simple four-fold classification that identifies the spatial situation for each grid cell. Each cell identifies a lithology and its coastal setting.
Foreshore and backshore data, onshore (beyond the backshore but within the forecast inundation zone) and offshore (area below low-water line) coverage.
Cliff height
Estimated cliff height in metres, determined from digital terrain model (DTM) analysis. Measured from the high-water line to the cliff top.
Height in metres from 0 - >100 m.
Cliff erosion
The worst-case erosion susceptibility classification of the cliff or backshore deposits. Click on a cell in the map for more information.
Cliff erosion, worst class scenario.
The mean erosion susceptibility classification of the cliff or backshore deposits. Click on a cell in the map for more information.
Cliff erosion, mean class scenario.
The base lithology (lith1) erosion susceptibility classification of the cliff. This is the first lithology above the high-water line that will be predominantly subjected to wave processes.
Cliff erosion, base lithology (lith1) erosion susceptibility classification of the cliff.
Inundation
Maximum sea-level inundation extents as defined by UK Climate Projections – UKCP18 sea- level rise climate scenarios for future sea-level rise.
Maximum sea-level inundation extents.
Subcoast potential subsidence rate (PSR)
The potential subsidence for an area considering the combined effects of the geological factors at that location. Provided as % and mm/yr.
Potential subsidence rate in mm/year.
Area statistics
A range of regional statistics has been generated from the baseline datasets to provide an authority-level overview of coastal properties, cliff erosion and flood susceptibility. These are all provided under the Open Government Licence .
- Coastline cliff erosion: the erosion susceptibility classification based on the geological properties showing the worst and mean scenarios for the coastline
- Multi formations: length of coastline that is made up of cliffs with multiple different geology layers
- Inundation: maximum sea-level inundation extents as defined by UK Climate Projections , UKCP18 sea-level rise climate scenarios for future sea-level rise
These are available in the BGS Onshore GeoIndex.
Coastline management
Happisburgh falls within the Shoreline Management Plan for Kelling Hard to Lowestoft (SMP6) and has a ‘managed realignment’ policy.
Many of the coastal defences constructed along the north Norfolk coast were installed in response to the catastrophic flooding that occurred on the night of 31 January and 1 February 1953. These coastal defences have been largely successful in reducing coastal erosion and limiting the longshore movement of sediment: their installation led to a marked stabilisation of the coastline at Happisburgh and a reduction in cliff erosion. However, by trapping sediment, the natural nourishment of beaches in down-drift (south-eastwards) areas has been restricted, causing a lowering of beach profiles and enhanced coastal erosion.
By the late 1980s, sections of the coastal defences at Happisburgh had fallen into a state of disrepair and, following more storm damage in 1991, a 300 m section of defences between Happisburgh and Cart Gap was removed. Between 1994 and 2010, the coastline to the south of the village retreated by up to 150 m, causing a large embayment to form and over the past 20 years, 35 homes have been lost to the sea.
Much of the sediment eroded from the cliffs has been transported southwards down the coast to Sea Palling, where it has been trapped by a series of shore-parallel artificial reefs which were constructed during the late 1990s with the aim of preventing coastal flooding and inundation.
Schematic of the cliff-line retreat looking north-west. Removal of a section of breakwater in 1991 due to storm damage has led to the development of a large embayment due to accelerated rates of coastal erosion.
A range of regional statistics have been generated from the baseline datasets to provide a Shoreline Management Plan-level overview of coastal properties, cliff erosion and flood susceptibility. These are all provided under the Open Government Licence .
- Coastline cliff erosion: the erosion susceptibility classification based on the geological properties showing the worst and mean scenarios for the coastline
- Multi-formations: length of coastline that is made up of cliffs with multiple different geology layers
- Inundation: maximum sea-level inundation extents as defined by UK Climate Projections , UKCP18 sea level rise climate scenarios for future sea level rise
These are available in the BGS Onshore GeoIndex.
Aerial photographs
Comparison of aerial photos of Happisburgh over a 20 year period. Left: 1999; right: 2019. Google Earth © 2020 Infoterra Ltd & Bluesky. Image NASA
Onshore and offshore data from BGS
Onshore and offshore agencies and media
Gallery
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