Dear Editor,
I refer to the many articles in the press by various government officials and others on global warming, LCDS and the impending sea level rise and its consequences on the coastal areas, and would like to enquire as to whether the new sea level has been established and what are the projected engineering sea levels to be used in the design format for present-day coastal structures.
An article in SN on August 17 by Dr B Ramcharran stated that the sea level in Guyana since 1950 had risen 1.7 feet, ie 510mm in accordance with a measurement by World Bank expert, Gerald Meier. The lawyer also recommended relocation of the population to higher ground. He did not provide info on costs, location, etc, for this operation.
The rise in sea levels will shorten the discharge window for sluices as well as reduce the hydraulic head between internal drains and sea and river sluices’ outlets. In other words drainage time will be reduced resulting in longer periods of flooding during periods of heavy rainfall. There will also be increased wave action on sea defence structures. It is imperative that a new sea level allowing for a projection for future increases be established and used for design purposes of coastal structures, including sluices, sea defences and embankments, etc.
The Hydraulics Division in collaboration with the University of Delft established the present sea level that I used for the design of the concrete sea walls and sluices during the 1960s and 1970s. Although the concrete walls are in good shape some 45 years later, I am very concerned about the battering the sea defences took in Better Hope/Plaisance last year, resulting in the destruction of the protective gabion baskets and displacement of the boulder slope, berm and coping. To date no repairs have been carried out.
If this is an indication of what is to come, I am indeed sorry for the people living on the East Coast of Demerara. The coastal areas have been neglected by the government for several years.
I have not read anywhere what the new level is, or about the government intention to establish this revised level, only rhetoric about impending sea level rise and global warming. The government to date has spent over US$100M in the last few years in riprap sea defences, mostly in the riverain areas, and recently awarded sea defence contracts in the amount of some 14M euros for riprap sea defences for the East and West Berbice areas.
I have looked at the riprap built about 15 years ago and at present, and they all look the same to me – same toe and embankment levels, boulder sizes, etc. The outlet sea and river sluices also appear to copy the design used several years ago. I do not believe these new works are designed with any projection for sea level rise.
I would welcome a response from the relevant authorities.
Yours faithfully,
Malcolm Alli
