Is the Amaila hydro plant viable in view of rising sea levels?
Is it economically viable to build the US$1B Amaila hydro plant in view of rising sea levels? In an article published Aug 1, 2013 in the Toronto Star, American scientists warned that it is too late to reverse the effect of greenhouse gas emissions and that rising sea levels of 7 to 10 ft are inevitable in the coming years for American cities, including Miami and Jacksonville. Guyana is on the same side of the Atlantic Ocean and will also be affected by the same amount of rising sea level.
Presently, in Guyana 90% of the population lives on the low-lying coastlands, which is about 4 ft. below high tide. If the sea level should rise another 3 ft or more in the coming years it would be detrimental for people living along the coast.
The sea level was first measured in 1961 and to date no one knows the present level. Driving a marked stake in the sea and measuring the level of the water at high tide as was done some time ago is not an indication of the true level. It is much more complicated than that.
The present sea defences around Georgetown and environs were realigned, designed and built in the ’60s and early ’70s and have a factor of safety of only 1.1 against rotational slips if the foreshore erodes. It is customary to re-align the sea defences every 40 years or so in Guyana. In Georgetown the old Baron Hora Siccama and the British seawalls were re-capped and raised 3 ft in 1968, and a new bitumen grouted boulder seawall was built in 1972. East of the Kitty pump station the concrete walls were built in 1968 and 1974. All these walls have not been maintained since this government came to power in1992. The government has also allowed a nightclub to be built directly over the boulder sea wall and a hotel within the sea defence reserve, all in defiance of the Sea Defence Act.
Monitoring of the foreshore levels also have not been carried out since the 1980s.
Recent overtopping of the sea defences around Conversation Tree are an indication of what is to come. Fortunately, Sithe Global has pulled out of the Amaila hydro power deal, but negotiations to build it are still going on. The plant will be headquartered in Georgetown.
In my opinion by the time the government takes over the plant, if built and handed over in 25 years time (5 years to construct and 20 years for Sithe to maintain and operate) Georgetown and its environs may have to face re-location.
The government has no alternative but to hold the present sea defence alignment between Better Hope and Camp Street. I doubt whether they have the engineering expertise and experienced workers to do so.