Monitoring and management of subsidence induced by longwall coal mining activity

About this Document

Longwall coal mining is the most common underground coal extraction method in Australia because of its relatively low cost, strong safety record and efficiency in removing coal from deep seams.

This report describes modelling tools and approaches for predicting subsidence and monitoring and measuring the surface water and groundwater related impacts of subsidence due to longwall coal mining.

Based on a long history of longwall coal mining in New South Wales, a generic approach is presented for investigating subsidence-related impacts on water resources that can be applied in Queensland where longwall coal mining is at an earlier stage. The approach uses a broad risk assessment to first identify and document the value of assets at possible risk from mine subsidence, then uses predictive techniques to identify the likelihood of impact and monitoring results to validate the assessment and refine the risk assessment. It provides guidance to proponents and regulators on the appropriate components and sequence of investigation, spanning the life of a mine (from exploration through to post-mining management stages).