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Work to dredge a new channel for boats in the Grand-Cul-de-Sac lagoon has been completed. Safety measures have been implemented as part of the project.
A new channel has been carved out in the Grand-Cul-de-Sac lagoon. This change did not come without its challenges. In fact, the work, which began in May, was originally expected to take three weeks. In reality, the “project” took much longer. This was due to specific reasons outlined by Sébastien Gréaux, director of the Territorial Environmental Agency (ATE).
“The channel’s initial route was not followed,” the ATE director explains right away. “We shifted slightly further north to avoid a seagrass bed.” Despite core sampling and testing, when we began dredging the sand, we stumbled upon a graveyard of dead corals. The sand would no longer flow through the pump, so we had to change our dredging method. This slowed down the progress of the work. ” The work is now complete. “Markers have been installed so that boats can easily find their way, with buoys equipped with lights,” explains Sébastien Gréaux. “The last buoy, in the channel, is for swimmers. It has a handrail because swimmers sometimes get swept away by the current in this area. This will allow them to regain their strength.”
Reusing the Dredged Sand
The ATE director emphasizes that the dredging of a new channel is part of a broader project for the area. “There was also a safety concern for swimmers who found themselves swimming in the boat traffic zone,” he recalls. “In fact, we’ll be reaching out to hotels and swimmers to explain that they should avoid swimming near the yellow buoys. And we’re also asking boats to stay close to these buoys to prevent accidents.”
Using suction pumps, an average depth of just over one meter was excavated to create the channel. Sébastien Gréaux notes that the dredged sand was deposited in the two areas of the beach where erosion is most severe: the Guanahani peninsula and the Sereno area. “Both have obtained environmental permits to reuse some of the sand,” he emphasizes. “But they’ve committed to replanting vegetation to hold the sand in place. Sereno will also install hydraulic piles, which are wooden piles. This method has already been used elsewhere and has proven effective. On the one hand, they’ll break up the swell, and on the other, they’ll hold the sand in place. It’s a fairly lightweight system, so if we see that it isn’t making much of a difference, it can be easily removed. But this is an initial test we want to conduct to combat beach erosion.”
25 abandoned moorings removed
At the same time, the Regional Environmental Agency noted that many moorings had been abandoned. “We took the opportunity to remove them,” explains Sabastien Gréaux. “There are nearly 25 of them, including tires filled with concrete, and so on. There have always been moorings in the area, and some of them are quite old. We have 65 boats under contract in the bay, and some have been lost over time. So it’s hard to know who these moorings belonged to.”
A radar in the channel
Also in Grand-Cul-de-Sac, a radar camera has been installed at the channel. It measures the speed of passing boats. “We’ve had accidents and injured sea turtles, so we want to make sure people are actually traveling at five knots as required by regulation,” explains the ATE director. “We won’t issue citations based on this camera since it’s not an official radar. However, for boats under contract, if an owner doesn’t play by the rules and repeatedly exceeds the speed limit, they’ll receive a first warning, then a second, and after that, their mooring permit will be revoked. ” Given that there’s a nearly ten-year waiting list to secure a mooring in the bay, there’s no doubt that this threat will be far more effective than a simple fine.
