Akosombo (E/R), Oct. 30, GNA – The Volta
River Authority (VRA) has stated that the Akosombo and Kpong Dams are safe and
pose no threat to public safety, as the Authority has implemented a
rigorous Dam Safety Programme with an excellent maintenance culture.
The dams, shall therefore, continue to serve their purpose for many years to come.
This was disclosed when authorities of the VRA took the media on a tour of the two facilities on the theme: “Dam Safety: The Case of VRA Hydroelectric Dams.”
The visit was conducted in collaboration with the Ghana Journalists Association.
Mr Christian Atsu Dagbui, the Principal Engineer, Civil, VRA, mentioned overtopping, foundation defects, piping and structural failure of the materials used in dam construction and inadequate maintenance as the most frequent causes of dam failures.
Dams, he said, therefore needed to be continually supervised and inspected throughout its whole life to ensure that it remained in good state.
He explained that, the design lifespan of a dam body was a time-span varying between the concession period and typically 100 years, adding that, life-span of hydro-mechanical steel structures, electromechanical equipment control units was shorter than that of the main civil/structural components.
“The life-span of any dam is as long as it is technically safe and operable and its safety can be assessed based on an integral safety concept known as Structural Safety, Safety Monitoring, and Operational Safety.
“Therefore, as long as the proper handling of these safety issues can be guaranteed according to this integral safety concept, the dam can be considered as safe,” he added.
Mr E. Ada Asomonsti, the Director of Engineering Services Department, VRA said some maintenance activities for dam safety included cleaning and probing relief wells in galleries, checking and sounding relief wells in dykes, repairing to seepage monitoring devices, controlling of vegetation growth on dams and surrounding and lubricating of various parts of the spillway gates.
VRA, he said, attached much importance to dam safety, hence, subjected the monitoring, operation and maintenance activities of the two hydro dams to one of the highest standard of scrutiny, “the Independent Expert Review Board”.
“The 50-year of Akosombo life have been uneventful. The performance of the reserviour retaining structures, powerhouse intake structure, main dam, spillways No.1 and No. 2 and the saddle dam continues to be fully satisfactory in conditions similar to those registered in previous five-year inspection report, since the first one by the original board in 1970” , the May, 2015 international expert report said.
He said a review and rehabilitation of the Kpong and Akosombo Dam Safety Monitoring System/Instrumentation Project (2013 – 2015), was executed by WAPCOS Limited (India) at a cost of US$3,946,000.
Rehabilitation of the Kpong Dams East and West Dykes and Spillway Project, which is currently on-going and being executed by Sinohydro Corporation Ltd, China, from 2018 to 2020, was at an estimated cost of US$6,802,727.62, he disclosed.
Mr Asomonsti noted that data collection, quality control, analysis, presentation and storage were key in the Authority’s monitoring programme.
“Thresholds and corresponding response actions are defined and clear for all stakeholders.
“Routine Periodic Inspection, Comprehensive Dam Safety Evaluation, and Constitution of Dam Safety Review Board/Panel are some of the international industry best practices,” he said.