Scouring of the foreshore from the earlier overtopping and severe wind caused the latest overtopping of the sea defences

Dear Editor,
I refer to the recent overtopping of the sea wall as well as the earlier overtopping earlier this year, and state that the situation is indeed serious and in my opinion was caused by scouring of the foreshore from the earlier overtopping, with severe wind.

I was the engineer who designed this section of sea wall in the ’70s. It was built in 1974 with a British loan by Wimpey, a British construction company. From what I have seen on the Internet it is obvious the foreshore has eroded appreciably, resulting in the severe overtopping causing flooding and damage to the earth embankment. Since this section of sea wall was built as well as the Georgetown sea defence in 1972, no maintenance was ever carried out by this government.

Engineers should have been carrying out soundings to determine the level of the foreshore and come up with solutions to build it back. This is impossible since you do not have a hydrographic section any more.

The sea defence map with foreshore levels for over 30 years was also destroyed in 1987. This section of sea wall consists of RC coping, concrete berm and slope, toe piling and 4 layers of gabion baskets. There is no doubt in my mind that the stone in the gabion baskets has been dislodged similar to what happened in the Better Hope/Plaisance areas a few years ago.

There have been reports in the press about raising the concrete coping higher. The level 62.50GD is about the highest you build to. Any higher could result in rotational slips.

The concrete sea defences are designed to last a minimum of 35 years, and can last even longer with regular maintenance.
It should be noted that you cannot re-align the sea defence any more in this area, and the government must the hold the present alignment at all costs. It will be indeed a formidable task.

Yours faithfully,
M Alli

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