Groundwater impact assessment in mining

The challenge

Understanding the unseen

Groundwater supports biological systems, agriculture and industry in Australia and is also vital to the health of local culture and recreation.

As such  it is important to protect and manage groundwater resources, including when they may become impacted from mining activities.

To quantify the environmental impact of coal mining, a mine’s impact on ground- and surface water systems needs to be understood.  This is difficult and subject to controversy because:

• water systems are usually complicated, poorly characterised and in high demand
• the interactions between surface- and groundwater systems and the biosphere are delicate and intricate
• mining affects surface- and groundwater flows in complicated ways, and
• mining impacts can spread kilometres from a mine and last for decades, meaning large-scale models are required for accurate projections.

Our response

A powerful modelling ecosysyem

We applied out our experience in building large-scale, detailed and accurate numerical models to assess the impact of coal mines on surface- and groundwater systems in the Hunter Valley region in New South Wales.

Main section shows a map of the New South Wales, Australia. Outlined in red is the Hunter Valley boundary used for the assessment model which extends past the land border on the coast and into the sea. Outlined in black is the land boundary of the Hunter Valley. Sections coloured in blue show lakes and water reservoirs. Lines in blue show watercources. Mine footprints are outlined in pink. Graduated pixelation around the denoted mine areas the relative amounts of drawdown associated with each mine.

Show image description

The Hunter Valley is a major coal producing region, supporting numerous coal mine operations in the area.

Using the mines own observational data, we built detailed conceptual and numerical groundwater models of the region.

These models were then enhanced by our deep knowledge of underground mining impacts on rock masses and aquifer hydrogeology, producing models with unprecedented accuracy.

Our supercomputing capability enabled us to assess very large regions, understand cumulative interactions of multiple mines, and assess long-term impacts.

We also performed extensive uncertainty analyses to quantify numerous “what if” scenarios which are particularly valuable in supporting investment decisions and managment into the future.

The results

Better management of groundwater impacts from mining

Our groundwater modelling has been applied in several mining jurisdiction to understand environmental impacts on groundwater arising from coal mines.

Arguably, Australia's most critical resource is water.

Accurate environmental impact assessment is now demanded by regulators, the public and mining companies to understand the impact of mine designs on groundwater and surface-groundwater interactions.

Our unique expertise in undertaking regional scale assessment like this is helping mine operators understand these impacts on water resources, both near and distant to the mine, in the short and long term, and under different “what if” scenarios.

Accurate information is enabling better mining decisions and improved environmental outcomes.