SRK is carrying out a major water management study for a confidential client that is currently developing several coal contracts extending 150 km in Kalimantan, Indonesia. Our services cover water monitoring, supply, drainage, storage, diversion, discharge and closure planning over the life of the project and address design, costing and scheduling of all water and sediment management infrastructure. Given the complexity and scale of the project along with an average annual rainfall of 4500mm, key challenges lie ahead.
A fundamental component of any mine water management plan is achieving a representative water balance. This is especially difficult early in project development, as it relies on design specification data for forecasting water demand, and on environmental data for planning water supply, where information is often incomplete or inaccurate.
Typical demands include potable supply, process water, construction water, dust suppression and vehicle washing. All supplies must be identified and characterised for yield, reliability, seasonality and location. Balancing demand to supply yields over time becomes central for design specification, permit application, infrastructure scheduling, risk assessment and cost optimisation.
Modelling is used to evaluate risk and to identify and test strategies to secure a safe supply, integrating and optimising all of the mine water system flow, storage and quality processes. The resulting strategies determine infrastructural requirements, costing and scheduling.
Once the strategy is developed and documented, it can inform planning over the project life. With water usage increasingly constrained by social, environmental and statutory factors, the mine water management plan becomes important for operators and regulators alike, for all aspects of water usage, storage and discharge.
SRK successfully applied the GoldSim package to the water balance studies: GoldSim is a modelling platform that supports dynamic probabilistic simulations.
The demand forecast was developed in liaison with our client and their design team.
Reliability estimates for the surface water storage and river intake were made using runoff models embedded in GoldSim to simulate operations using representative data in Monte Carlo trials. The trials reflected changing conditions in land use, runoff and infrastructure.
Model output was used to specify the river intake, pit sumps, water storage dams, sediment ponds and diversion channels.
SRK prepared a detailed preliminary water management plan, which the client is currently refining for subsequent project stages.
