Guyana coast land is about 6 feet below sea level and it is extremely expensive to build much higher sea defense works.
Sea walls in Guyana are built with about a 1:10 to 1:20 probability of occurrence. That means that there is about 10% to 5% probability that flooding will occur in any year.
Also, Guyana is subject to influence of the Amazon and Orinoco rivers which cause erratic erosion and flooding along the coast land.