7 strategies to create more resilient mine dewatering

Chetan Mistry, Strategy and Marketing Manager at Xylem Africa

Johannesburg, Gauteng, SA (24 February 2025) – Mining and water are synonymous, though it's not always a constructive relationship. Water helps reduce dust, cool and wash equipment, and assist in transporting and filtering material dug up from pits and tunnels.

Water's destructive risks
However, water is also a destructive presence. Mining activities release groundwater trapped among the soil and rocks. Water on the surface naturally flows towards the depressions created by digging, becoming very critical during heavy rainfall or flooding events. Dewatering is the main method to manage such risks.

A dewatering failure can have catastrophic consequences. At the start of 2025, the Kombat copper mine in Namibia had to halt operations when both its permanent dewatering pumps failed, causing wide-scale flooding. This disruption isn't brief – operations may remain stalled for up to 9 months due to drainage, damage assessments, equipment recovery, and focus on worker safety.

Mines need resilient dewatering systems to prevent such issues. While there is always a risk of problems, modern practices provide effective ways for reliable dewatering.

Every mine faces unique conditions around how water impacts their safety and operations. The mining industry and its suppliers have developed novel strategies to derisk dewatering that other sites can apply. These strategies range from the type of pumps used to leveraging data for predictive maintenance.

Resilience measures for dewatering
Dewatering risk management benefits considerably from modern innovations.

1. Appropriate pumps: Dewatering is demanding, intensified by changes in water flow, levels, and pressure, and avoiding clogging from solids and other debris. Modern dewatering pumps focus on these challenges. For example, they include seal failure safeguards, no-clog impellers, dry priming, variable motor speeds, and high-quality strainers.
2. Use portable pumps: Most mines permanently install dewatering pumps. However, there is also scope for portable pumps to address acute and unexpected pooling. These pumps vary from larger pumps on trailer beds to submersible dewatering pumps that can be transported on the back of a vehicle and moved with limited manpower (inspired by portable dewatering pumps used on large ships).
3. Machine-integrated rig pumps: A new generation of dewatering pumps can be integrated with mining equipment. Called rig pumps, these are attached to drilling rigs, from which they draw power. Rig pumps can self-prime and are operated from inside the rig cabin, reducing risk to personnel.
4. Temporary pump strategies: Having a rental strategy in place provides quick intervention if there are problems such as equipment failure or sudden surges in water levels. Rental pump strategies also reduce maintenance disruptions to operations through quick access to bypass options.
5. Leverage digital twins: Digital twins are digital copies of equipment, using data from the real-world equipment. Mines are using digital twins to predict maintenance for utilities such as pumps, as well as run event simulations. The leading digital twins operate through data platforms provided by mining equipment vendors, and they can focus on a handful of metrics or cover every aspect of the equipment.
6. Hydraulic Dewatered Stacking: Water trapped in tailings dams creates risks such as environmental contamination and dam collapses. Hydraulic Dewatered Stacking (HDS) is a cutting-edge tailings management technology that substantially reduces and recycles water from tailings streams. Using layers of coarse sand, HDS gives water a quicker exit, lowering demands on dewatering.
7. Pressure management: Modern sensors provide detailed pressure information to manage water's impact on a site. Mines are using both permanent and portable pressure systems, including submersible transmitters, to collect real-time information about pressure changes in wells, pipelines, and ponds, helping prevent overfill and dry run incidents.

Water and mines have a close but contentious relationship. Dewatering failures can be incredibly catastrophic. But on the other hand, modern dewatering resilience significantly mitigates risks to operations and lives, reduces pressure on maintaining and managing dewatering systems, and even improves profitability through water recycling and sustaining operations. – To see more, go to www.xylem.com