Background
SGME completed a landform stability analysis for the final landform of the tailings storage facility. The mine is an underground polymetallic mining operation located south-east of Cobar in central-western New South Wales.
Objective
The mine operates a tailings storage facility with a central high-solids discharge that has resulted in an elevated cone deposition beach that is characterised by long and steep slope angles. The rehabilitation strategy includes minimal reprofiling and a preference for limited water management to achieve a water-shedding design.
SGME developed calibrated Water Erosion Prediction Project (WEPP) and landform evolution models to assess the cover and erosion risk of the rehabilitated landform. WEPP is a continuous simulation program developed by the United States Department of Agriculture’s Agricultural Research Service.
Solution
Rainfall and overland flow simulations were conducted to gather crucial erodibility parameters for both the cover and landform materials. These simulations measured hydraulic conductivity, rill erodibility, interrill erodibility and critical shear stress to provide essential data for use in calibrating the WEPP model. The calibrated WEPP model was then used to predict potential erosion rates over a 100-year period for the rehabilitated landform using various cover designs.
In addition to erosion rate predictions, the WEPP model calibration results were used to calibrate a landform evolution model. This model integrates multiple landscape-forming processes into a dynamic simulation to project landscape changes over centuries to millennia. It offers insights into erosion hotspots, potential failure points in the cover and landform, and how these factors may evolve over time.
SGME’s successful execution of these simulations and models enabled a precise estimation of erosion rates in the rehabilitated landform, identified erosion-prone areas and provided critical insights into the long-term stability and performance of the cover and landform systems.
Our commitment to excellence in environmental services, especially in mined land rehabilitation, is reflected in our use of advanced techniques such as rainfall simulation and flume experiments. These methodologies ensure accurate data collection leading to precise predictions and tailored strategies for erosion management. By prioritising environmental sustainability, we help clients mitigate risks and achieve long-term stability in their landforms.
