Dams & Hydro

Midmar Dam

he project involved a 3.5 m raising of the FSL of Midmar Dam using a reinforced concrete labyrinth spilling. No raising of the flank embankments was required and the work was limited to demolishing the spillway bridge and piers, a modification of the spillway crest and the construction of 3.5 m high reinforced concrete labyrinths.

Midmar Dam was originally constructed in 1965 and was designed for the full supply level to be raised by the simple addition of radial gates. When this solution was designed by the owner, the local water board, who were paying for the proposed raising, commissioned ARQ to evaluate the design proposals. ARQ reviewed the postulated design and various alternatives and came to the conclusion that a fixed reinforced concrete labyrinth was the most cost-effective option and could be implemented at a cost of approximately 30% of the radial gate raising option.

Stieglers Gorge HEPP

The Stiegler’s Gorge Hydropower project was taken to an advance stage of development and tender documents were prepared in 1980.  At the time, however, the regional power demand was not considered adequate to justify the project and development plans were suspended.  Very significant ongoing electricity demand has recently brought the project back into consideration and a mandate has been granted to Hydro Finance to take the project forward into implementation.

Aloe Cove Dam

Aloe Cove Dam at Zwartkop, near Krugersdorp, is the second highest new generation rubble masonry concrete (RMC) dam yet constructed in South Africa. Containing over 15 000 m3 of masonry, it also represents the largest dam yet of this type.  The 23m structure is situated on the Crocodile River and is classified as a Category III dam (largest) in terms of the South African dam safety legislation. The dam has a spillway capacity of 3000 m3/s.