COASTS CASE STUDY: North Norfolk coast (Cromer, Overstrand and Happisburgh)

45 miles of coastline, including some of the most rapidly eroding coastline in the world (averages 2m/ year)

Opportunities:

• A UNESCO biosphere reserve until 2014. An area of wetlands and salt marshes and an important habitat for wildfowl and marine animals including seals (Blakeley Point (spit)– an area of outstanding natural beauty). Attracts a large number of tourists for birdwatching 
• Tourism includes visiting beaches and attractions such as the pier at Cromer. Over 25% of jobs (over 10,500 jobs) are now in tourist sector bringing in a total of £470 million in 2014. 
• The coastline offers opportunities for the harvesting of mussels, cockles, shrimps, crabs, and bait as well as some commercial shore-netting e.g. Cromer Crab 
• There are a number of field study centers for educational visits such as Aylmerton Study Centre and Holt Hall
• Some areas are cultivated for sugar beet and cereals.
• Off-shore wind farm. 88 turbines off the coast of Sheringham.
• Reclaimed land at Blakeley Point is used as pasture and a nature reserve

Causes of erosion:

• Geology: soft, impermeable clay base with soft, permeable gravel above.The impermeable clay traps water percolating through cliffs, causing it to pond and discharge from the cliff face. This leads to an increase in pressure in the cliff, reduced strength of the cliff, which may cause landsliding/ slumping caused by weathering
• As the cliffs are made of soft varied materials with a low resistance this also means that they are very vulnerable to wave erosion and mass movements caused by undercutting, sometimes as much as 10m in one go
• Waves have a long fetch (North Sea).
• Main sea defenses (revetments) destroyed in 1990 storm
• Government is enforcing a Do Nothing Policy of managed realignment.
• Narrow beach, unable to absorb much wave energy
• Sea wall to the North at Cromer, Overstrand prevent erosion there and therefore reduce available sediment that could be deposited by LSD at Happisburgh
• Dredging at Yarmouth to the South also deprives Happisburgh of sediment by LSD.
• Granite reef at Sea Palling restricts sediment movement.

Problems/ consequences 

• Coastal erosion and cliff recession: Happisburgh & Overstrand. Very severe. Averages 2-5m per year at Happisburgh.
• At Happisburgh: over 26 houses lost to the sea 
• Homeowners cannot take out insurance.
• Homes become unsellable / lose value.
• Coastline permanently disappearing.
• Wave action can undercut these cliffs making them prone to failure, especially on low cliffs (10 meters or so), such as at Happisburgh
• problem area – Beach Road runs out to the cliffs and properties here are situated right on the cliff edge
• in 1990 a storm destroyed around 300 meters of wooden revetment to the east of Happisburgh
• in 1996 another length of revetment was lost – rapid cliff erosion followed and six cliff top properties were lost
• at the base of the cliff there is a combination of gabions/flexible concrete blocks/3″ steel tubes banded together to lie in a breastwork 
• They have also tried groins and most recently, rock armor.
• Flooding at Blakeney Point. 1953 especially severe (307 killed)
• River Glaven becomes blocked by shingle from advancing spit and floods Cley village.

Action: Happisburgh

• Coastal Concern Action Group set up to lobby North Norfolk District Council.
• North Norfolk District Council gave £200,000 in 2006 for 5,000 tonnes of boulders as rip rap / rock armor..
• Villagers raised a further £50,000 for a further 950 tonnes of boulders.
• This bought the village a 10 year reprieve.

Actions elsewhere:

• The River Glaven has been diverted to prevent recurrence of floods
• Sea walls with promenades have been erected along the coast at Cromer and Overstrand with wooden groins to keep beach, gabions and some rock armor
• Some revetments at Cromer have helped create a beach
• Beach replenishment by offshore dredging