Agri Minister says best engineering decision will be made
Government’s decision to construct a canal at Hope to drain the East Demerara Water Conservancy (EDWC) into the Atlantic Ocean has come in for scrutiny and at least one experienced engineer, Malcolm Alli, has publicly declared that the proposed construction is not the best option.
President Bharrat Jagdeo recently announced that his government will spend $3B towards the construction of this East Coast canal which is expected to serve as a more efficient and less destructive means of releasing water from the conservancy. At present, when the EDWC is at a dangerous level, water from the conservancy is drained through the Maduni and Lama sluices. The water then flows into the Mahaica creek. This has caused catastrophic flooding in the Mahaica and Mahaicony areas in three of the last four years.
In an attempt to counteract this problem, the government is proposing that a relief channel be constructed from the EDWC to the Atlantic Ocean through the Hope/ Dochfour area on the East Coast of Demerara. This is an option that had been recommended since the Great Flood in 2005.
However, recently several persons, including engineers and farmers, have been questioning the wisdom of such a canal, arguing that there were better and cheaper ways of solving the problem.
When these points were raised with Minister of Agriculture Robert Persaud, he told this newspaper that the exact structure of this relief channel has not been confirmed as yet and that the best engineering decision will be made concerning this outlet. Persaud said that his ministry will not be dismissive of any ideas coming from experienced engineers but emphasized that the best technical decision will be made. He said that the project has gone out for tender and consequently this means that it has been opened to all those persons who feel that they have something worthwhile to contribute.
When Stabroek News contacted President of the Guyana Association of Professional Engineers (GAPE), Melvin Sankies for comment, he said that it is imperative that advice from older engineers be sought. Sankies said that the older engineers have both knowledge and experience and consequently can be useful to the younger engineers who may be tasked with the project.
Meanwhile, this newspaper was reliably informed that an experienced local engineer has been tasked by the government to review the proposals on the project and to advise accordingly.
In a letter published in the January 13 edition of the Stabroek News, engineer Malcolm Alli argued that the proposed canal was not the best option to drain the conservancy. Alli played a significant role in the MMA scheme as well as designed and supervised the construction of the 7-door Abary Control Sluice, and has many years of experience as an engineer. According to him, extensive studies carried out by the Hydraulics Division during the 1960s determined that the Land of Canaan (LOC) sluice on the East Bank was the best location and option to drain the conservancy.
The studies by the Hydraulics Division determined that an Atlantic relief would likely be subject to some tidal lock which would be undesirable for a spillway operation. According to Alli, the discharge sluice at the sea wall end could only work on a tidal basis six hours a day discharging a small amount of water daily.
The sluice at Land of Canaan is a 5-door high sill sluice that was built in the 1960s. And according to Alli, it was built specifically to drain the EDWC. He explained that the sluice can discharge 2000 cusecs of water when working on a 24-hour basis, independent of the tide.
Alli, however, asserted that the sluice at Land of Canaan is not working as it should and that specific work should be done to improve its capacity. This, he said, would be a cheaper way of solving the problem that the authorities had in dealing with draining the conservancy.
Outlets
Similar thoughts were echoed by Project Director of the Guyana Citizen’s Initiative (GCI), Dr Rupert Roopnaraine. When contacted by Stabroek News, Roopnaraine said that the authorities may be better advised to at least consider improving the outlets towards the Demerara River rather than investing so much money in what is clearly a very challenging undertaking. Previously, the GCI had called for the rehabilitation of the Cunha canal and outfall to aid in the conservancy’s drainage. And according to Roopnaraine, it would not hurt for the authorities to at least look at improving the sluice at Land of Canaan. He said that based on engineering advice he has received, releasing water from this end of the conservancy would greatly ease the strain on the side of the EDWC nearer to the Atlantic Ocean.
When Minister Persaud was asked about the Land of Canaan sluice, he said that the “jury was out as to whether the capacity of this sluice could be improved”. While saying that there were no immediate plans to work on this sluice, he did not rule out work being done in the future. He once more confirmed that efforts were being concentrated on the resuscitating of the Cunha outlet to the Demerara River, which he said was only operating at about 40% of its capacity and which obviously could be improved.
Persaud said the peculiar situation with the conservancy is that the water levels stored towards the Atlantic end of the conservancy were higher than the levels at the Demerara River end. Consequently, that was why work on the relief channel that drains into the Atlantic Ocean was being implemented. Observers say such a phenomenon might indicate blocked internal drainage channels or greater sedimentation in the northern section of the conservancy.
Meanwhile, Alli also said that the failure to maintain the 7-door Abary Control Sluice was another cause of the problems with draining the conservancy.
He said that a certain amount of water had to be released from the sluice daily so as to keep the Abary River alive, but this was never done. According to Alli due to the failure of water to be released, the Abary has become silted for about 45 miles. He also said that he does not believe that the sluice was functioning.
Technical advice
When the Agriculture Minister was asked about this sluice, he said that he had been advised by the MMA authorities that this sluice can be operational and can release water from the conservancy into the Abary creek. He said that he was told that during the low-tide that the sluice is opened.
The minister, however, hinted that this sluice is not working as it should and explained that he is waiting on the technical staff of the MMA to provide him with some more “technical advice” on the state of this sluice.
One farmer from the Abary area, in a letter published in this newspaper, said that the sluice has not been working for more than twelve years. Persaud, however, stated that he was not in a position to confirm or dispute whether the sluice has not been properly functioning for such a lengthy period.
Meantime, Alli also opined that the conservancy has not been properly maintained, and consequently this has resulted in it reaching a critical stage of siltation and vegetation inhibiting its storage capacity.
During a recent tour of the EDWC by media personnel, Secretary of the EDWC Board, Stephen La Fleur said that over the years several of the conservancy channels had been blocked up by vegetation and silt and that work had been and continues to be done to clear some of these channels.
Alli also argued that to facilitate this new relief channel may cost more than the $3B budgeted since considering the magnitude of the project. According to him, the proposed works for the relief channel will be extensive since the canal has to be a high level canal with some 80 ft bed width and about 10 miles long.
Further, it would require the construction of two large sluices in addition to several bridges over the canal, a bridge at the roadway, access roads and more.
President Jagdeo has announced that money has already been budgeted to get the project started by June/July but said that he is currently in negotiations to secure part funding for the project. If all goes according to plan, the proposed date for the completion of the channel is June 2010.
However, another letter writer Charles Sohan suggested that the proposed deadline was overly ambitious, especially when the amount of work required is considered. In his letter, he said that “based on the requirements for data collection, design and construction…it is inconceivable that this project could start in June 2009 and be completed by June 2010. He added that “given the size and complexity of this project (the Hope Relief Channel) it is unlikely that it could be completed and functional in under three years”.
Sohan also questioned how the sum of $3B (US$15M) that has been budgeted was determined. He said that “it was mind boggling as to how this figure was arrived at, since no design, bill of quantities and costing have been prepared for this project.”
