Jones & Wagener was appointed by BHP Billiton Energy Coal SA (BECSA) to undertake the design of the upgrading of the Enkeldebosch Canal, taking clean runoff around the run-of-mine tip at the Boschmanskrans Section of Middelburg Mine. This followed flooding of the tip at the end of February 2009 due to runoff exceeding the capacity of the elements of the canal. This resulted in flooding of the tip and a costly interruption in operations.

As the Enkeldebosch Canal represents the last link in an extensive water diversion system, designed to take clean runoff around the opencast mining operations, J&W recommended that a detailed inspection of all elements of the water diversion system be carried out to ensure that the system operates as intended.

The Scope of works comprised:

• Upgrading of Enkeldebosch Canal and Eastern Cut-off Canal
  • Widen Enkeldebosch Canal from a 3m wide invert to a invert of 10m
  • Construct soil nail retaining wall at DMO conveyor
  • Raise the Enkeldebosch Canal berm to provide sufficient free board
  • Construct new transition structure at start of lined canal over mining spoil
• Upgrading of overflow weir
• Extension of conveyor culvert
• Construction of West Road Collector Canal, the canal is lined with Armourflex blocks to prevent souring
• Upgrading of North-Western Cut-off Canal

Location