POTENTIAL MANAGEMENT AND REHABILITATIONREQUIREMENTS OF ENVIRONMENTAL EFFECTS FROMLONGWALL SUBSIDENCE ON STREAMS, LAKES ANDGROUNDWATER SYSTEMS

摘要

Following a series of highly publicised environmental issues relating to subsidence of rivers,rnstreams, lakes and other surface water bodies, as well as groundwater systems, the longwall coal mining approvalrnand environmental management process in NSW now has a significant focus on predicting, monitoring, managingrnand rehabilitating adverse effects on surface water and groundwater systems.rnDue to the recent public and regulatory focus on the issue, future longwall layouts and approvals may be requiredrnto demonstrate that unacceptable effects will not be imposed on rivers and streams. This may result in significantrnchanges to panel layouts, or if no acceptable management and rehabilitation measures are available, the worstrncase scenario may occur where an environmentally sensitive water body may not be undermined.rnThe range of environmental effects that have been directly observed by the author, as well as reported effects, orrneffects that could be anticipated from subsidence in NSW coalfields are outlined. Measures required to assess thernpotential effects on environmental systems, potential rehabilitation requirements, potential risk assessment andrnmanagement procedures relevant to water related issues are discussed.rnThe effects of longwall subsidence are outlined for a range of geomorphological areas, whilst an indicativernprocess that can be used to assess the potential severity of effects on surface water and groundwater systems,rnwhich leads to the degree of attention required to manage them, are described.