Delivery Tunnels

The delivery tunnel is made up of two sections: the Delivery Tunnel South, from the 'Muela power station to the Lesotho- South Africa border, and the Delivery Tunnel North, from the border to the Ash River Outfall in South Africa.

Construction of the Delivery Tunnel South went smoothly. The l5km tunnel boring machine (TBM) excavation was completed 20 months ahead of schedule, realising a saving of M85,7 million on the original R42l,6 million contract. Included in the structure are two steel-lined sections that form the crossings under three rivers. Under the Ngoajane River is an l8m section of pipe housing the flow meters that measure the volume of water delivered from Lesotho to South Africa. This part o(the tunnel was the first part of Phase lA to be completed.

The 22km-long Delivery Tunnel North was also completed ahead of time (by three months) and under budget (a R52 million saving). Only one TBM was used, with the tunnel being lined concurrently with precast concrete segments, thus saving time. The first section of the tunnel, under the Caledon River (the South Africa-Lesotho border) was constructed using traditional drill-and-blast techniques, and is steel-lined.