More geotextile tubes needed to strengthen sea defence, prevent clogged outfalls

Last Updated on Saturday, 24 October 2015, 20:18 by GxMedia

One of the geotextile tubes that has resulted in the huge build-up of sand as high as the Georgetown Seawall near the Police Headquarters just east of Camp Street.

Faced with rising sea levels, weakened sections of the coastal sea defence and blocked outfalls, the head of the National Task Force Commission (NTFC) Retired Major General Joseph Singh has recommended the use of more groynes.

Briefing the media on the multi-disciplinary task force’s work so far to help restore Guyana as a land of great attractiveness and prosperity, he said more groynes should be constructed as part of a cost-effective approach to help boost the sea defence system.

“We have to decide whether we will only reinforce the seawall or invest in groynes. If we don’t invest in groynes, then you are not going to get that accretion which allows mangroves, for example, to take root and thrive,” said Singh, a former Executive Director of Conservation International (Guyana).

He noted that the construction of each mile of sea defence is estimated to cost US$1.5 million.

Singh pointed out that one of the groynes opposite the former Guyana National Service Sports Ground, Georgetown has resulted in a huge build-up of sand that is at the same height with the seawall.

“So where you have no groyne there is no accretion, where you have a groyne, it catalyses the accretion which helps to strengthen the sea defences,” he added.

The Head of the NTFC observed that many of the old groynes have been badly eroded and many have disappeared, causing the build-up of many outfalls at the mouths of rivers and canals. “The sling mud that we have that creates problems for our outfalls is exactly because we don’t have those groynes so even if you clear the outfalls, the next high tide it comes back and it’s there,” he told reporters.

The retired head of the Guyana Defence Force (GDF) said the only way to remove the sling-mud from ten outfalls is to have a pump jetting water to ensure that there is no accretion.

The Public Infrastructure Ministry had last year announced the installation of six geotextile tubes along the Kingston to Kitty sea defence to create a groyne field and so contribution to beach stabilization by retaining sediment drifting in a westerly direction.

The tubes are manufactured from geosynthetic based materials which are factory sewn to achieve the desired formation. Installation of the tubes is carried out by filling with sand or suitable dredged material.

The NTFC has been playing a major role in coordinating human resources and equipment at the local, regional and central government levels to address various environmental concerns such as poor drainage, mined out areas, thick vegetation and waste disposal across the country.

The NTFC’s five year programme includes preparations for Guyana’s 50th anniversary celebration next year, completion of the various works by 2018 and the implementation of a sustainable strategic plan. “The idea of this being a one-off exercise like a normal clean-up because Christmas is coming or Independence is coming, that is not the case. This is a long-haul, this is a systemic project, a project which has to be embedded in the psyche of all Guyanese,” he said.

The NTFC aims to inculcate in Guyanese the need and importance of governing communities through activities at all levels  beginning at homes.