Document Type

Conference Paper

Publication Date


Publication Details

This conference paper was originally published as Kay, D, Barbato, J, Brassington, G and de Somer, B, Impacts of Longwall Mining to Rivers and Cliffs in the Southern Coalfield, in Aziz, N (ed), Coal 2006: Coal Operators' Conference, University of Wollongong & the Australasian Institute of Mining and Metallurgy, 2006, 327-336.


Extraction of coal using longwall mining techniques causes subsidence which has potential to affect surface features, including environmentally sensitive areas such as rivers and cliffs. There are currently a number of proposed extensions to coal mining operations in the Southern Coalfield of New South Wales that are seeking to mine close to rivers and cliffs. These proposals have attracted some community concern at a local and regional level. This concern is largely founded on impacts that have occurred as a result of previous mining activities, the majority of which occurred directly beneath the impacted sites. It was therefore considered a timely exercise to revisit the history of impacts that have occurred as a result of mining close to rivers, particularly where they have occurred in the Southern Coalfield. The rivers reviewed include the Cataract, Nepean, Georges and Bargo Rivers. Potential effects of longwall mining on clifflines can include rock fracturing; rock falls from cliff lines, riverbed fracturing and water loss. Consideration will be given in this paper to the major mining, geometrical, geotechnical and environmental factors affecting the likelihood of rock falls from cliff lines and riverbed fracturing and water loss, and reference will be made to previous mining experience at collieries in the Southern Coalfield of New South Wales. Where the mining has not occurred directly beneath rivers, rock fractures, water loss and rock falls from cliff lines have occurred to a much lesser extent when compared to rivers that have been mined directly beneath. The fractures have been observed in local, isolated areas only and were minor in nature. In addition, changes to flow conditions have not been observed in these areas. A clear understanding of potential impacts from mining of longwalls beneath or near rivers and cliffs is essential for developing relevant baseline studies, assessing potential impacts and formation of appropriate remedial methods. Management plans can then be implemented to monitor and mitigate the identified risks without unduly restricting the extent of mining.