Georgetown, GINA, March 27, 2008.Efforts are continuing to strengthen the coastline against the increasing threat of the sea level rise in various areas including the section along the lower East Coast Demerara that was affected by overtopping during the last spring tide period.
At present, focus is being placed on strengthening the weakened section of the sea defence that overtopped during the recent excessive high tides before the next spring tide which is expected from April 4th to 9th with the highest tide anticipated on the 7th.
Engineers from the Sea Defence Unit of the Ministry of Public Works and Communications have already conducted the necessary surveys to determine the nature of the work that needs to be done and the quantity of materials required.
Monitoring continues to be done while efforts are being made to acquire geo-textile to be used in the vulnerable areas to prevent the embankment from eroding, should there be any overtopping.
In addition, sea defence works are progressing in the Turkeyen/Ogle area where approximately $176M is being spent to construct 1100 metres of ‘rip-rap’ structure. The contract for this project was awarded last December and it is expected that the works will be completed by June/July this year.
Reinforcing and stabilising of sea defence structures are also ongoing at Gangaram, along the Canje river in Region Six while two projects were recently awarded for ‘rip-rap’ construction at Orangestein, East Bank Essequibo and Henrietta, Leguan Island in Region Three. The works at Orangestein will cost approximately $78M while about $33M will be spent to effect the other project at Leguan Island.
These projects are part of Government’s continuing investments to improve the country’s defence against the sea particularly in light of climate change which has resulted in a rise in sea level and other unusual weather conditions.
The recent spring tides that caused overtopping in the Vryheid’s Lust, Better Hope and Montrose were said to have been aggravated by a low pressure system in the Atlantic that generated wave action and the current La Nina condition which is associated with easterly gusty winds.
Experts predict that there is expected to be a global sea level rise of one metre over the next 50 to 100 years, with Guyana experiencing about two metres due to its unique characteristics that include mud coast, large landmass behind a low lying coast.
Among the many initiatives being embarked upon by the administration to deal with sea level rise is the construction of ‘rip-rap’ structures that are designed for a 30-year period and take into account expected sea level rise over this duration.
In addition, this design caters for adequate settlement of the structure since the country has a weak soil foundation where the embankment is subject to a lot of settlement.
The rock armour dissipates wave energy better and therefore, precludes the need for a very high sea defence as would be required with a concrete structure. Rip-rap construction is done at a cheaper cost, utilising local materials (except the filter fabric which is imported) and results in more sea defence being addressed.