What started as an urgent attempt to prevent a coastal town from being completely flooded has turned into an environmental headache for authorities in Senegal.
Last October, a channel was dug across the Langue de Barbarie (the Barbary Tongue) — a 100m-wide sandy peninsula that stretches along the country’s northern coast for about 30km, separating the Senegal river from the Atlantic Ocean.
Regional authorities had hoped to divert water from the river to prevent further flooding in the town of Saint-Louis, located near the border with Mauritania.
”When we decided to build the channel, Saint-Louis was already under water and there were four more waves of floodwaters coming toward the city,” says water affairs official Ibrahima Diop. Saint-Louis had experienced floods before, but never of this intensity.
The channel, located just south of the town, was initially 4m wide. However, it has since widened to the point where it is encroaching on several villages in the area that depend on fishing and small-scale agriculture for their livelihood.
”We’re sitting on hot coals and don’t know where to turn. We know that sooner or later, we’re going to have to leave our villages, which will be swallowed up by the rising waters,” says Mamadou Sarr, a 60-year-old inhabitant of the village of Gandiol.
The effects of the channel are also being felt by a nature reserve on the Langue de Barbarie, which provides breeding grounds for a multitude of birds and turtles — and serves as a tourist destination.
”Ever since the channel was dug, the site has been disturbed and could disappear altogether. Already the sand banks, which served as nesting places for certain birds and turtles, are disappearing because of the encroaching waters,” says Samuel Dieme, assistant director of Senegal’s national parks.
Adds Abdoulaye Ndiaye, Senegalese projects coordinator for Wetlands International, an NGO: ”The opening will disturb the area’s ecosystems. The fresh-water table in the area is … absorbing more and more salt water, which could pose serious water supply problems for the population.”
A second opening, created about 30km from the first, also widened unexpectedly. The combined pressures of river and ocean caused the channel to become about 600m wide in less than a month (the width later increased to 800m). However, the pace of this activity has since slowed considerably — something scientists ascribe to tidal deposits of sand.
Amadou Ndiaye, a retired hydraulics engineer, is critical of the government’s efforts to stem flooding in Saint-Louis.
”People didn’t think about the eventual consequences of their actions,” he says. ”The opening of this channel was a mistake that they could have avoided. Now we cannot foresee what its consequences will be, although they surely will be very serious.”
Landing Mane, a geography professor at the University of Saint-Louis, says the waters of the Senegal should have been diverted between Saint-Louis and the Diama Dam instead. The dam is located about 32km upstream from the city.
But as Diop sees it, the urgency of the situation didn’t allow officials the luxury of studying many options.
”We needed to act quickly so the city wouldn’t flood. We didn’t have time to think about the eventual consequences. We had to act before all else.”
He adds that there are records of channels being carved in the Langue de Barbarie before, including in 1850, 1884, 1906, 1932 and 1936. But, says Ndiaye: ”These breaks were natural and always closed up by themselves.”
Environmental activists gathered in Saint-Louis last month to study the situation at first hand, and Senegalese authorities are also trying to find ways of undoing the damage.
”Right now, we’re conducting studies to see how to deal with the situation. We’re in the process of developing several possible scenarios to stem the widening of the channel. The results of these studies will be submitted to the government,” Diop notes.
However, news service IPS could not ascertain when these studies are expected to be complete.
One of the ideas put forward is that of establishing a water-regulation system at the opening itself — although no price tag has yet been ventured for such a project.
”It will not be an easy job to stabilise the opening because of the make-up of the ground. The Langue de Barbarie’s soil is a fine sand, which cannot withstand the rush of the waves,” says Marie Tew Niane, a researcher in geophysics at the Gaston Berger University of Saint-Louis. — IPS