Dear Editor,
In this beautiful and unusual country, 90 percent of the population exists precariously on a sliver of coastland three to four feet below the level of the sea at high tide. Almost all of our agriculture is located on this speck of real estate. Every one of us who plies a trade or pursues a profession or furrows a row, however we may carve a living on this narrow stretch of land, is subconsciously aware of the seawall and its importance to our very existence. Without the sea defence, the coastal belt would be submerged; Guyana as we know it would cease to exist.
In fact, the structure which we identify as a single seawall originated as random and disjointed construction efforts by neighbouring estates to reclaim the fertile coastal land from the sea. Beginning with the Dutch around 1750 and continuing with the British up to the early 1900’s, each planter was concerned only with his own estate, and applied whatever ingenuity he could devise to keep the sea out to preserve his crop. Enormous resources went into sea defence. Planters used sheet piling, stone filled wave screens or earth dams behind fascine (timber filled) groins to protect their estates. These structures often actually caused erosion and did more harm than good. High dams were built to separate estates in the hope that the failure of one estate’s poor sea defence would not affect its neighbour. The overall result was expensive, unplanned, and ineffective. Estates were lost when planters could no longer afford sea defence, and this in turn brought neighbouring estates under increased threat.
At the turn of the twentieth century, the crisis threatened the entire colony. Plantations Bel Air, Hague, La Jalousie, Windsor Forest, and Vreed-en-Hoop all went out of sugar production in the first decade of the century as a result of the ravages of the sea after the failure of their defence efforts.
In 1906, a Sea Defence Commission was formed to investigate the problem and identify solutions. The Commission experimented on various methods of sea defence, but made no substantial progress. More drastic measures were required. In 1913, Parliament amended the Sea Defence Ordinance to vest all sea defence under the care of the Director of Public Works. In 1915, Sir Egerton, Governor of the colony, formed a Committee which inquired into the problem and reported four weeks later, in January, 2017:
“The emergency is too grave to waste words upon it. Our inadequate and unscientific sea defences have been broken in several places within a few miles of Georgetown during the four weeks of the Commission’s existence. The high Spring tides have flooded through two great breaches at Triumph since we last met and have closed the public road during several hours for some days, washing away the parapets and causing great general damage. The matter is vital.”
This prompted quick action. The following month, Gerald Otley Case, an English civil engineer, was retained to provide a solution. Case inspected the coast from Essequibo to Berbice, and produced five separate reports on the East Coast of Demerara, West Coast of Demerara, Essequibo Coast, Corentyne Coast and the Islands of Leguan and Wakenaam. Case recommended a system of reinforced concrete groynes and walls in a design which came to be called the Case System of Coast Protection. The essential points of this system were to construct long, low groynes which would use the force of the sea to build up sand and mud in a gradient which would permit waves to harmlessly roll up the shore and expend their energy without threat.
The groynes were designed to collect both material moved along the bottom by waves and carried in suspension in the littoral current. Where sea walls were essential, they were designed with a concave wall and curved in an attempt to simulate the natural gradient of the shore. The shape and location of the groynes were designed to accommodate the specific wave action in the geographic location. In the Essequibo, they were placed 1000 feet apart and were 500 feet long. In Demerara, they were 1500 feet apart and projected 750 feet from the shore.
Work commenced on the Case System of Coast Protection in July, 1916, with special permission from Great Britain and the United States to divert material and equipment from the War effort, the first World War being then in full flow. The cost was $4,500,000.
The Case System was successful beyond all expectations. By November, 1917, the Commission reported that the foreshore at Lusignan, Beterverwagting and Clonbrook on the East Coast, had built up on average 3.5 feet, and in some places from 5 to 6 feet. In Clonbrook, where in March, 1917 very rapid erosion had taken place, and where a part of the public road had been washed away, the foreshore had built up by accretion to 2 to 3 feet above the height of the Public Road. By 1919, the project was complete. As we embark on the year 2019, we can be reminded of the centenary of a grand and ambitious undertaking, which allows us one hundred years later to keep the sea only at the back of our minds.
Yours faithfully,
Timothy Jonas