Case studies

EIA of mining activities on dugong populations

Client: Australian Marine Conservation Society
Location: Southern Great Barrier Reef

We performed an environmental impact assessment of an open-pit coal mine project in the Styx River basin located in Central Queensland, about 10 km upstream from the Great Barrier Reef World Heritage Area. The objective of this project was to evaluate the extend of the area that could be impacted by mine-affected water flowing from the Styx River in Broad Sound, which is home to dugong and flatback turtle populations. By using the multi-scale model SLIM, we managed to simulate the ocean circulation with a resolution of about 100m in Broad Sound area. Broad Sound is characterized by a very intense tidal circulation and our hydrodynamic simulations show current speeds well above 2 m/s. We then released virtual particles representing either a dissolved pollutant or sediments at several locations within the Styx River and up to 5 km offshore. Our results suggest that both dissolved pollutants and fine-grained sediments (such as fine silt or possibly coal dust) would have the potential to reach the dugong sanctuary in Clairview as well as flatback turtles nesting islands of Avoid and Wild Duck. Coarser-grained sediments have a more localized dynamics and tend to accumulate in the Styx River. They never reach ecologically-sensitive areas.

In collaboration with Antoine Saint-Amand (UCLouvain - ELI)