Matla coal mine owned by diversified resources group Exxaro Resources is rolling out a wetland conservation project which enables it to expand its underground operations while preserving one of the larger and ecologically valuable wetland systems in Mpumalanga’s Highveld. Exxaro believes that the Matla wetland project is unique in that, in conserving the valuable ecological resources, the approach adopted is a combination of a river diversion and the adaptation of a mining method. The result maintains the water flow and function of the Blesbokspruit/Rietspruit ecosystem and protects its biodiversity.

“This is an example of innovation and nature working hand in hand. At Matla we are going below the wetland using undermining, a technique typically used when a mine extends under a building, roadway or town,” said Dr Joseph Matjila, Exxaro’s environmental manager. “We have adapted this approach into an innovative engineering design that allows our operations team to extend Matla’s underground shortwall mining operation while minimising the impact on the wetland that lies above the surface,” he said.

The water flow and function of the wetland is protected through a shortwall mining design that allows for even subsidence of the area. The entire wetland area will drop by 1.8 m, reducing the formation of ponds and ensuring the continued natural flow of water. The flow of water into the wetland is controlled in a way that protects the ecosystem and allows mining to continue without the risk of flooding.

The Blesbokspruit/Rietspruit wetland is one of the larger and more sensitive wetland systems in the area. This innovative solution has ensured that the normal wetland function and biodiversity will remain intact. It has protected some 120 ha of identified non-channeled riparian wetland and another 132 ha of the seasonally inundated non-channeled floodplain at the bottom of the valley.

Design and planning of the wetland project started in 2006 with implementation taking place from 2007.  The project has been approved to continue until 2017. The Matla team has worked closely with the Department of Water Affairs, Department of Mineral Resources and non-governmental environmental groups and stakeholders in developing the project. It forms part of the mine’s approved environmental management plan and water use licence.

In the 2009 financial year Matla coal mine produced 11.3 Mt of power station coal which was supplied to local Eskom.