Dewatering: strategic in achieving mining plan objectives

How many times have we heard operators say that they had to rent pumps in a hurry to deal with rising water levels in the spring? This reactive approach often disrupts mining operations and causes unexpected production losses.

On the other hand, factoring dewatering into the early stages of mine planning allows for proper modelling of the pumping system’s evolution. This proactive approach results in robust, flexible systems tailored to site realities while optimizing costs. It also gives clients a clear view of upcoming investments and makes it easier to plan for system installation.

Dewatering systems must be strategically sized in collaboration with the client. For example, the design flow rate must come from an analysis that compares required system costs with acceptable risk levels, based on evaluated precipitation data. A mine near a lake may require extra groundwater drawdown stations around the pit to reduce water infiltration and make it easier for drilling and blasting.

Several key factors must be considered to design effective dewatering systems:

• Design flow rate, based on climate, hydrology and hydrogeology data, plus cost and risk assessment

• Pit elevation and equipment location according to the mining plan

• Site characteristics (location, lifespan, mine type, available energy)

• Water treatment needs and overall site water management

• Equipment accessibility and maintenance requirements

• Optimization of existing equipment use

There are also various ways to optimize the system:

• Use several systems in parallel for greater efficiency across a wide range of flow rates.

• Allow temporary water accumulation in pits during spring to reduce design flow and avoid oversizing.

By planning properly and maintaining a big-picture view of mining operations, you can achieve robust, efficient and cost-effective dewatering systems.

With over 20 years of experience in dewatering projects, BBA brings together multidisciplinary teams to support you every step of the way, from preliminary studies to commissioning.