The Gates Open at Low Tide
Georgetown stands below the Atlantic that lies a few hundred metres from its main street, and has done since the Dutch drained this coast in the eighteenth century. The city's canals, its street grid and the word Guyanese still use for a sluice gate are all consequences of that, and so is the flood that cost the country most of a year's economic output in 2005.
At Kitty, where the seawall runs east out of Georgetown, a set of heavy doors sits in the concrete and for most of the day they are shut. They are shut because the Atlantic on the far side is higher than the water in the canal behind them. When the tide drops far enough, the doors are opened and the head of fresh water does the rest: a canal draining a large part of the city empties itself into the sea for a few hours, until the water outside climbs back and pushes them closed again. It is the least complicated piece of engineering in the country and everything else depends on it.
The structure is a koker — Dutch, and the word has survived in Guyanese English for two centuries after the Dutch themselves left. There are dozens along this coast. They exist because the coastal plain, which is a few per cent of Guyana's territory and holds something like nine people in ten, is a strip of marine clay lying below the level of the high spring tides. The capital, the port, the parliament, the sugar estates and the rice fields are all on the wrong side of the water line, and they stay dry because of an eighteenth-century drainage scheme that has to be maintained in perpetuity.
What the Dutch left
The Dutch West India Company was on these rivers from the early seventeenth century — Kyk-Over-Al on the Essequibo, then Berbice, then Demerara from 1746 — and for the first century and a half the plantations sat inland along the riverbanks, where the ground was higher and drier. In the second half of the eighteenth century they moved to the coast, because the marine clay was far more fertile and because a ship could load without working its way upriver. The coast, though, was mangrove swamp at sea level. Making it farmable meant a front dam against the sea, a back dam against the water coming off the interior, side-line canals to move water across the estate and drainage trenches to move it out — a complete hydraulic system per plantation, each of which had to interlock with its neighbours' or fail.
A monument nobody calls one
That work was done by enslaved Africans with shovels, in waterlogged clay, without machinery of any kind. Walter Rodney, in A History of the Guyanese Working People, made the comparison Guyanese schoolchildren are still taught: the volume of earth moved to build the coastal polders — on the order of a hundred million tonnes — exceeds what went into the Egyptian pyramids. The system is a monument on that scale. It is simply not described as one, partly because it is invisible from anywhere except the air and partly because it is still in daily use, which tends to disqualify a thing from being treated as heritage.
Guyana's coast does not drain into the sea. It waits, twice a day, for the sea to drop far enough to let it, and then has a few hours in which to do a full day's work.
Drainage by permission of the tide
The defining weakness is that the whole thing drains by gravity into a body of water that rises and falls. A koker can discharge only when the sea outside is lower than the canal inside, which means two windows a day, each a few hours long. Rain does not consult the tide table. A heavy tropical downpour arriving on a rising spring tide has nowhere at all to go for six hours, and it stands in the streets until the gates can open — which is why an ordinary bad afternoon in Georgetown floods and then drains away by evening, and why people here read the tide as attentively as the forecast. Pumps have been added over the decades and pumps are the expensive answer: they burn fuel, they need servicing, and there are never quite enough of them at the hour they are wanted.
January 2005
Behind the inhabited strip, on slightly higher ground, sits the East Demerara Water Conservancy — an impoundment held by an earth dam tens of kilometres long, built to store irrigation water for the dry season. It also, unavoidably, holds a very large volume of water above the heads of everyone living on the coast. In January 2005 the rain that fell over a few weeks was far beyond what the conservancy was designed for. The dam came under threat, releases were made into a drainage system that was already full, and much of Georgetown and the East Coast went under for weeks. The death toll was around thirty-four, most of it leptospirosis contracted in floodwater rather than drowning. The UN's Economic Commission for Latin America and the Caribbean assessed damage and losses at roughly US$465 million — close to sixty per cent of that year's gross domestic product. Guyana lies south of the hurricane belt. There was no wind in this. It was rain, and a system that could only drain at low tide.
A canal, and two parliaments
The engineering answer was to give the conservancy a second way out. The Northern Relief Channel — universally called the Hope Canal, after the village it runs through — carries water from the conservancy straight north to the Atlantic across about ten kilometres of East Coast Demerara, with a head regulator at the inland end, a bridge taking the public road over it, and an outfall sluice of eight gates at the sea. Construction ran from 2010 to 2015 and cost something over three and a half billion Guyanese dollars, and it was fought line by line: the opposition of the day called it a procurement scandal in earthworks, cut it from budgets and questioned every stage. It was built anyway. It has since done what it was built for, which is the least dramatic and most useful thing public infrastructure can do.
The coast is on loan from the Amazon
None of this would be maintainable if the shoreline stayed where it was, and it does not. The mud that makes the Guianas coast comes out of the Amazon, more than a thousand kilometres to the south-east, and travels north-west in a series of enormous banks — something under two dozen of them between the Amazon and the Orinoco — migrating along the shore at a rate usually given as one to three kilometres a year. Where a bank sits offshore, the water is calm and silt-laden, mangroves colonise the flats and the coast builds seaward. Where the shore lies between banks, the waves that were being damped now break on it directly, the mangroves die back and it erodes fast. A stretch of seawall can spend twenty years behind an apron of mud and mangrove and then find itself in open water, and the timetable is set at the mouth of another country's river.
Which is why mangroves here are protected as sea defence rather than as habitat, why the restoration programme launched in 2010 planted them in front of the wall rather than anywhere more photogenic, and why sea defence is a permanent line in the national budget rather than a project with an end date. Guyana has recently come into a great deal of oil money and is spending part of it on the coast, which is the obvious thing to do and also a strange loop to be caught in: one of the countries most exposed to a rising Atlantic is paying for its wall out of the proceeds of what is raising it. Nobody in Georgetown finds that observation novel. They have lived below the tide line for two hundred years and they know precisely what is holding the water back, which is more than most cities can say about themselves.