All existing and proposed mining operations are potentially at risk of flooding. An understanding of the flood risk for existing and planned mines can safeguard people, infrastructure and production continuity. MINE SITE SURFACE WATER MANAGEMENT AND FLOOD RISK ASSESSMENT Understanding the hydrologic, hydraulic, and geomorphological response to flooding events allows informed decisions for mine planning and operation. Using detailed land survey information, a flood assessment can provide input regarding the flood extent, duration, and other characteristics to allow assessment of flood-related consequence to the mine site. In addition to legal implications, flooding may impact upon: Worker safety Production – potential significant economic loss Environment – water disposal, clean-up costs, or impacts on wildlife and vegetation Long-term reputation – media coverage, share price Re-insurance after the event – potential increase in insurance premiums MWH uses hydrological and hydraulic modelling to estimate frequency and magnitude of floods, assess the potential impacts of flooding on the project area and inform the design of flood protection and key infrastructure to protect your business and reduce the impacts of flooding. Rainfall-runoff and water balance modelling 1D and 2D open channel and floodplain hydraulic modelling, using HEC-RAS, TUFLOW, InfoWorks, MIKE suite, waterRIDE and other industry-standard applications Flood inundation risk and flood hazard mapping Modelling of flood management and mitigation scheme options Assessment of environmental effects River diversions and realignment Bank stabilisation and erosion studies Hydraulic structures design Material take-offs, cost estimation, and preparation of construction plans and specifications Surface water engineers and mine staff can together estimate the costs and relative risks of flooding impacts to the mine operations. Outcomes of the flood analysis can be further assessed through a multi-criteria analysis and risk assessment process to identify the most cost-effective mitigation option.