Monitoring finds more than a metre of sand has been washed away from the beach and structural movement within a section of the seawall
“It could slide forward and slump down if we didn’t do anything," says Dave Robson, who's West Norfolk Council's environmental health manager.
The council's been closely monitoring sections of the coastal defences, and more than a metre of sand has been washed away from the beach in front of the Green at Hunstanton, around 40cm this summer alone.
Dave Robson
The ongoing beach erosion has exposed more than one metre of the sheet piling along the structure, and digital level monitoring's identified cracks and movement in sections of the sea wall.
Engineers say repairs need to 'be carried out to prevent further deterioration and potential structural failure of the seawall over time'.
Showing the exposed sheet piling
Showing the recent structural movement
The 200m section of seawall between the Rock Shop Slipway and Pier Head Building (referred to as Section F and G) on the North Promenade that requires interim works
Mr Robson wants to reassure residents and visitors it is safe for now, "We are always checking on the condition of the prom and have detected this early - but if there’s a significant change - we will adapt. It is safe to use."
The work being proposed is for around 10 thousand tonnes of rock to be piled in front of the seawall to prevent further movement, starting with smaller stones which would then be capped off with 10-tonne boulders.
Rock armour structure
The 'rock armour structure' will be around 9 metres wide and between two and three metres high - which will stabilise the seawall and prevent further movement, until there's a more permanent solution.
It'll cost around 2 millions pounds, and take around 10 to 12 weeks - parts of the prom and beach will be cordoned off once work is in progress, the exact date of which has yet to be decided.
Cllr Sandra Squire, Cabinet Member for Environment and Coastal, is reassuring local business, "It will be out of season work, so they'll be less of impact. We will try and keep disruption to absolute minimum."
Sinkhole
The vulnerability of our sea defences was all to clear in February, when a sinkhole appeared along the stretch between the Waterside Bar and the Oasis leisure centre.
The void measured about the size of a single decker bus. Repairs in March closed part of the walkway for two weeks while tonnes of concrete were poured in to fill it.
Sinkhole being filled in March
The Council's currently progressing the necessary consenting process for the interim works.
Cllr Squire adds, “The situation now requires intervention beyond routine maintenance, which is why we are taking proactive steps.
"We recognise that work of this scale will generate interest locally, and we are committed to keeping residents, businesses and stakeholders informed throughout the project."
Long term, the town's entire sea defences are expected to be renewed in a £40m government-funded refurbishment - although plans are yet to be drawn up.