How much longer before tide wins out?


SINCE the dawn of time, mankind has held a curious fascination with the sea and a desire to control the awesome power contained within its murky depths.

King Canute reputedly set his thrown beside the shore and commanded the tide to halt, whereas according Norse mythology, Thor, the God of thunder, was tricked into accepting a challenge to drink the ocean dry - but even in the legends, neither succeeded.

In the modern age, with our increasing ability to control the natural world through advancements in technology, we would like to think we hold a greater command over the oceans than ever before.

But despite the millions spent on coastal sea defences and the precise monitoring of tidal movements, an expert on the Lincolnshire coast believes there may come a point in the second half of this century when we cannot keep the advancing North Sea at bay any longer.

David Robinson OBE said: “By the end of this century the evacuation of Mablethorpe and Sutton-on-Sea will be a serious question, we may have to consider.”

Mr Robinson has lectured and written extensively on the changing nature of the Lincolnshire coast and methods of partially protecting communities from the encroaching waters.

He has monitored and analysed the ever changing nature of the coastal region caused by natural erosion and the man made effect of projects intended to halt the advancing tide-line following the floods of 1953.

On that night, nearly half a century ago, high spring tides combined with an unusually powerful storm surge, met by inadequate sea defences, demonstrated more horrifically than any other event in living memory, quite how devastating the sea can be.

A total of 307 people lost their lives along the Lincolnshire and East Anglia coastline and thousands of homes were destroyed, prompting a major rethink in how we protect ourselves from the sea’s deadly power.

Taller, stronger, sea defences were built along the Lincolnshire coast, intended to protect against a tide as high or higher than that which caused the 1953 floods.

By the 1980s, however, it became apparent to Mr Robinson and other experts on sea defences that the concrete barriers were inadequate in height and quality and so even taller, wider sea defences were built.

Following the construction of these enhanced defences, Mr Robinson began to notice an increase in beach scouring caused by the energy of waves reflecting off the sea defences and transporting sand offshore.

So severe was the effect of this scouring that in some places only two inches of sand remained above the clay bed.

Adopting a fresh tactic, the authorities began dredging sand from offshore and redistributing it onto the beach to create a ‘soft cushion’ defence in front of the hard sea walls - and so the Lincshore project was born.

However vital that defence method may have been in protecting lives along the coast, Mr Robinson pointed out that it marked a point of no return.

“Once they had begun the project it would have to be repeated annually forever to replenish the beach stocks that were perpetually moving southwards by longshore drift towards Gibraltar Point,” he said.

Today, that project remains the principal method of protecting the coast and maintaining the strategy of ’holding the line’.

Although we have not seen a repeat of the deadly floods of 1953, recent warnings from flood insurers and the emergence of sink holes on coastal dunes have highlighted the constant threat which looms offshore.

And Mr Robinson in his former role at the Lincolnshire Wildlife Association has noticed worrying repercussions affecting the Gibraltar Point wildlife reserve posed by the beach nourishment project.

“Every grain of sand from Mabelthorpe southwards ends up at Gibraltar Point,” he said.

“New ridges and sand bars are constantly emerging in the area posing significant problems for beach nesting birds such as the little turn and ringed plover.”

Although the changing geography of the area produces a ‘lovely mosaic of habitats’ it also makes the work of beach wardens and volunteers tasked with protecting the bird eggs from opportunistic foxes and magpies far more difficult as their nesting locations constantly change according to the varying coastline.

In the future Mr Robinson envisages more problems emerging as global warming causes the planet’s sea levels to rise at approximated a foot per century.

With a third of Lincolnshire already lying bellow the level of high tide, Mr Robinson believes the time will come when the question will have to be asked as to whether it is feasible to continue replenishing the beach.

Although rising sea levels could pose problems to coastal areas across the UK, Mr Robison believes Lincolnshire is a special case and the problems its communities face, far different to any other area he can think of.

‘Hold the line’ may be the best strategy for coastal protection today but one day we may have to consider retreat or face ever increasing expenses replenishing the beaches and fortifying defences.

“The coastline may look simple, but it’s not, it’s constantly changing and although you can adapt to the current situation, that situation will change over time.”said Mr Robinson.