Twice in the last century our shoreline has made sacrifices for the nation – first to extend Plymouth’s naval dockyard in the late nineteenth century, and again during the Second World War, when Slapton Sands became a rehearsal ground for the D-Day landings. Many servicemen lost their lives in that practice, and whole communities were moved from their homes. It is the first of those sacrifices – the dredging – that still shapes the crisis we face today.

Nowhere in the recent studies of Slapton Line is the historic dredging mentioned – yet the record is clear. Between 1895 and 1907 the great Keyham Yard extension doubled the size of Plymouth’s dockyard. It consumed around 1.3 million cubic yards of concrete – roughly 3.9 million tons – and the Admiralty’s approved mix of one part cement to two parts sand and four parts shingle meant that over two million tons of shingle and a million tons of sand went into it. Much of that shingle came from Start Bay.

Start Bay is a closed, relict beach system – the shingle and sand within it are effectively finite, laid down over thousands of years and never naturally replaced. Removing so vast a quantity of beach-building material set in train a slow, unstoppable retreat of the coastline.

The Skerries Bank dredging was licensed by the Liberal government of 1894, when the Office of Works granted a licence to the contractor Sir John Jackson. It carried a clear proviso: the work was not to expose the land above the high-water mark, nor to damage the foreshore or nearby property. In his 1896 application, Jackson insisted the quantities required would never be enough to disturb the cliffs or adjoining land.

He was wrong almost at once. As the dredging continued, the beach at Hallsands began to fall. In May 1897 the MP Francis Mildmay pressed the Board of Trade in Parliament over the damage to fishermen’s cottages and their livelihoods – yet the enquiry held that June, by which time the beach had already dropped some eight feet, concluded there were insufficient grounds to revoke the licence.

As the beach kept falling and the government did nothing, the villagers took matters into their own hands, removing the dredger’s marker buoys on 1 January 1902. The licence was finally revoked a week later, on 8 January 1902 – but by then between 1.25 and 1.5 million cubic metres of irreplaceable material had been taken. By March 1903 the beach had fallen more than nine feet. Incredibly, the very next year Jackson was granted a fresh licence to remove a further 0.7 million cubic metres of sand from the Skerries, two miles offshore.

The civil engineer and geologist Richard Hansford Worth studied the beaches of Start Bay in the years that followed. His analysis showed the shingle at Hallsands was made largely of flint and rock of distant origin – not material shed by the local cliffs, and so, once removed, gone for good. Later assessments of the South Devon coast reached the same verdict: the destruction of Hallsands was the inevitable consequence of taking away the shingle.

You do not need to be a detective to join the dots. The removal of millions of tons of non-replaceable material caused this man-made problem a century ago, and it remains the cause today. The beach has since been stripped from Hallsands, Beesands and, more recently, Torcross. With no material left at the Start Point and Skerries end of the bay, the natural defence of Slapton Line – the road and the communities that depend on it – has effectively been signed away. We believe a solution is within reach.