I was the first to bring to light the problems associated with this project.
First of all, I totally agree with the residents as they have a right to be concerned since the East Demerara Water Conservancy (EDWC) and all its problems are also now brought out into their backyards. I also agree that a detailed feasibility study is warranted under the circumstances.
The National Drainage and Irrigation Authority (NDIA) has stated that foreign and local experts have determined that an Atlantic outlet is required for the EDWC similar to the Land of Canaan Sluice (LOC) and should be located at Hope. The local experts were not named.
The LOC is a 5-door high sill sluice capable of working 24 hours a day and discharging 2000 cusecs. This would be literally impossible to achieve for the Atlantic discharge.
As an experienced design and construction engineer I am still trying to comprehend how a high level canal would fit into a low sill discharge outlet sluice without compromising its discharge capabilities. I am also trying to visualize not only the design but also the construction of the inlet sluice located between the crown dam and the conservancy dam as well as the design and merging in of the inlet sluice to the conservancy dam.
The soil in this area has literally zero shear stress, ie the bearing capacity is zero. It will also be a construction nightmare for the contractor undertaking the project.
Mott McDonald has worked in Guyana before and I believe worked on the Boerasirie scheme where an entire sluice floated away during construction. The sub-soil at Hope is also similar. I am not too sure about the role of the local consultants other than to provide surveys and geotechnical back up info to Mott McDonald.
Recently, the President lambasted both the local contractors and consultants generally for poor work and promised to institute monetary charges for poor performance.
Under the circumstances this is a costly project for Guyana and I feel the consultants collectively should provide a Performance Bid Bond and or have appropriate Liability Insurance guaranteeing their design work against any failure. This is standard in the consulting engineering industry.
NDIA should spell out its criteria for the design. Any resort to open the either the Lama or Maduni Sluices after completion of the project to relieve the EDWC and flooding the Mahaica residents should be considered a failure, since this project is primarily to prevent any such future releases.
Yours faithfully,
Malcolm Alli
