Reconstruction of Mabira dam and water facilities in Mbarara district (construction and supervision at Global International Services Ltd)

Abstract

Mabira dam is an existing reservoir which was constructed way back in 1940/50’s but first rehabilitated in 2003. It is an earthen embankment of approximately 300 meters, 5m high with a reservoir reach/fetch of over 3km and an estimated storage capacity of about 1 million cubic meters. The embankment was in bad condition with significant evidence of slope failure, especially on the upstream face/side. The longitudinal crack along the crest in the embankment was also potential for further slope failure which would result into washing away of the entire embankment thus immense destruction in the downstream areas. The spillway channels were non-functional thus posing a danger of total breach to the embankment. The facility is a source of livelihood for very many people who have settled around the dam within Rwanyahembe Sub County that basically use it for irrigation, cattle, and on small scale for human consumption after boiling. On 14th July 2017, a contract for the reconstruction of Mabira Dam and water amenities was signed between the Government of Uganda represented by the Ministry of Water and Environment (MWE) and Global International Services Ltd, the Contractor to have the Dam reconstructed. The reconstruction works commenced on 30th November 2017 and works were substantially completed on 27th September 2019 despite the extension of time for completion of 12 months up to 30th April 2020. The project schedule was acceptable though works were allowed 12 months’ extension beyond the intended completion date of 31st May 2019. This was due to the irrigator reservoir area part of the site not handed over to the contractor due to land acquisition problems. As a result, all activities that were an integral part of the irrigator reservoir were put on halt. These include; abstraction system, electromechanical installations, transmission, distribution, and irrigation system. Subsequently, a change of design of the reservoir to a reinforced type irrigator reservoir that could sit on the available land along the slope was adopted to stop further delay of the project. A variation in this regard was signed on the 20th March 2019 between the Client and the Contractor. Other aspects of the project were contained within a good grading range without deviation from the original project goals and objectives. The project has been completed exceeding the initial contract sum of UGX 8,798,418,711 to UGX 10,108,283,755. The contractor was paid an advance and eight (8no.) interim payment certificates.