GIBB, in a joint venture with Consolidated Consultants of Jordan (GIBB-CC JV), has been awarded the contract for detailed design and construction supervision for Lesotho’s Metolong Dam, which is part of the Water Supply Programme.

Gibb-CC JV is responsible for the design of the dam, the intake tower, outlet works and raw water pump station, which are the working elements of the dam.

The main objective of the Metolong Dam Water Supply Programme (MDWSP) is to supply potable water for domestic and industrial use, to Maseru and the neighbouring towns of Roma, Mazenod, Morija and Teyateyaneng. The construction of the Metolong Dam and associated infrastructure forms a significant component in the achievement of this goal.

According to Colin Logan, director of Dams, Hydropower and Underground Works at GIBB, the dam will be built on the South Phuthiatsana River, adjacent to the villages of Ha Seeiso and Ha Makotoko about 35 km from Maseru.

“The project forms part of the Lowlands Bulk Water Supply Scheme,which will improve access to water in the lowlands areas of Lesotho and support economic growth. The 83 m high, straight roller compacted concrete (RCC) dam with a crest length of 270 m, will have a storage capacity of 63.7 million cubic metres. The site is very steep, and one of the challenges will be to ensure access to the proposed dam wall to do the foundation excavations and the RCC placing. The blasting and excavation of the river diversion works on the left bank will also be challenging as it will take place during the wet season when flooding could be a problem,” says Logan.

The MDWSP is a five year project managed by the Metolong Authority. It began in 2008 and is expected to be completed in 2013. Impoundment of the Metolong Dam is expected over the 2012/13 wet season.

Sinohydro Corporation is the contractor for the construction of the Metolong Dam and raw water pump station. The contractor is currently under way with the site establishment.

Cape Town’s optic fibre project

Through the recent successful implementation of its Broadband Infrastructure project, the City of Cape Town has invested in its own telecommunications infrastructure network. This will reduce costs and contribute towards the economic growth of Cape Town. Leading consulting engineering company, GIBB led the project management and undertook the civil engineering design and construction monitoring of the R125 million, 500 km optic fibre network project.

Currently, the city spends about R70 million a year on telecommunications costs for telephonic and data services at municipal offices. The project in its entirety included laying a network of optic fibre cables across Cape Town with sufficient capacity to meet the City’s current and future needs. Thereby ensuring that the city has access to low cost broadband services to support the delivery of municipal services and have spare capacity available to third-party network users.

Certain elements of the project needed to be completed in time for the World Cup to ensure there was a network service available to the disaster management and traffic management team, to minimise disruption to traffic and prevent congestion in the city. The most challenges arose where the project runs through Cape Town CBD, which is an area of historic and congested services.

GIBB managed the process of coordinating the contractor’s activities to ensure that deadlines were met and challenges were averted or addressed.

On the outset of the project, GIBB was informed that the project needs to be completed using trenchless excavations to ensure minimal disruption to surface traffic, business and other activities. This was not possible due to the maze of existing services under the roads and sidewalks. GIBB then engaged meetings with various road managers to resolve a way forward in undertaking open excavations.

Municipal fibre networks have the potential to reduce operational costs for cities, increase competition and improve services in the telecommunications sector. In the long run, it will also benefit community organisations, and GIBB was happy to be part of the success story.