Managing groundwater in the world’s deepest mines: A strategic imperative for Sub-Saharan Africa

South Africa’s Mponeng gold mine holds the title of the world’s deepest, plunging nearly 4 km below the surface. Remarkably, six of the ten deepest mines globally are located in Gauteng Province alone. But, with depth comes complexity – and one of the most pressing challenges in these operations is water management. This is particularly true across Sub-Saharan Africa, where difficult natural conditions amplify the risk. For example, Zambia’s copper mines are among the wettest in the world.

Effective groundwater management in these conditions requires more than just equipment – it demands long-term planning, regional partnerships, and a lifecycle approach that extends beyond the active life of the mine to mitigate risks to the local environment.

Layered water risks below the surface

Deep mines in Sub-Saharan Africa often face water ingress from two directions: surface water descending through shafts and groundwater rising from below. Without proper control, these levels can quickly overwhelm operations. If dewatering pumps fail, entire mine levels – and even the full mine – could become inaccessible within days. The deeper the mine, the higher the risk.

But the challenge doesn’t end when production stops. Many of the region’s mines are located in semi-arid areas with low water tables. Over time, if unmanaged, groundwater can migrate upward through fractures created by mining activity. When this water – often acidic and contaminated with heavy metals – enters aquifers, the environmental consequences can be severe.

A cautionary example lies in Colorado, USA, where around 500 of the state’s 23 000 abandoned mines are contaminating more than 1800 streams. It is a stark reminder of the long-term impact unmanaged groundwater can have – and the need for preemptive action to avoid a similar outcome in Africa.

A lifecycle approach to groundwater management

Mitigating these risks starts with holistic, long-term planning. Groundwater management must be built into the mine’s design and operational strategy – not treated as a secondary concern. This includes deploying durable pumping solutions capable of withstanding corrosive, acidic water while maintaining high performance over time.

Close collaboration with local partners and service teams is essential. Not only can they help operators select and install the right equipment, but they also provide critical ongoing monitoring and maintenance. Pumps operating in aggressive groundwater conditions are prone to wear, reducing efficiency and increasing the risk of failure if not properly maintained.

Fortunately, early detection of performance issues can allow for minor refurbishments that extend pump life dramatically – from an industry average of 10 000 hours to as much as 45 000 hours. The financial benefits are significant: improved efficiency can save thousands of dollars annually per pump, and inefficient pumps can cost operators hundreds of thousands in excess energy usage alone.

Shifting from reactive to predictive operations

Given the harsh realities of mining in Sub-Saharan Africa, a reactive approach to groundwater management is no longer viable. Proactive partnerships with local OEMs with engineering capability and field service experts enable preventative and predictive maintenance, reducing downtime risk and ensuring that issues are addressed before they escalate.

When failures do occur, regional support becomes even more critical. Local teams can respond quickly to perform essential refurbishments and minimise downtime – a capability that remote providers often can’t match.

By planning for groundwater challenges from day one – and maintaining that focus through the full mine lifecycle – operators can protect their assets, reduce operating costs, and minimise environmental impact. In doing so, they lay the groundwork not just for operational success, but for long-term sustainability.

Read the article online at: https://www.globalminingreview.com/special-reports/10102025/managing-groundwater-in-the-worlds-deepest-mines-a-strategic-imperative-for-sub-saharan-africa/