Using integrated 2D flood models to assist mines to optimally reclaim surface water for operational uses

Global warming is a reality and very evident in South Africa where water shortages are now experienced in large areas of the country.  This is not only impacting our daily lives but also critical industries such as mines where large volumes of water are required on a daily basis to keep these industries operational.  Carbon emissions continue to be a problem globally where in 2015, in less than eight months, humanity has used nature’s budget set for the entire year. Global comparison maps have shown that global warming is the direct reason why South Africa is now identified as one of the countries where longer periods of droughts can be expected.  This impact of increased drought periods now force mines to optimise their return water strategies and look at innovative ways of surface water reclamation in a much broader context. 

Computer models such as the United States Environmental Protection Agency’s Storm Water Management Model (EPA-SWMM) are increasingly being used to assist mines to manage these extreme global warming trends. Recent rainfall data has shown the trend where either, “too little or too much” rainfall is recorded.  Typical “flash-floods” are experienced where large volumes of water are released in very short periods of time.  These flood events have been successfully modeled where the overland flow is simulated using the integrated 2D flood modeling capabilities of the model, the results of which are used to develop surface flooding risk maps and inform the mine’s emergency response plans.  These integrated 2D flood models are now being modified and used more strategically to optimally plan reclamation initiatives at the Mines.  

The paper covers the use of integrated 2D-1D capabilities in order to attain and mitigate high risk areas as a result of depth, velocity & depth in conjunction with velocity. It also presents the use of 2D-1D modelling of water harvesting and reclamation.