Monitoring of Coal Mining Around Large Dams

Mannering Creek Ash Dam has been successfully undermined once, and is currently being undermined again in a second seam. The dam has been monitored closely during each stage of the mining, and there is no evidence of any damage. Maximum vertical ground movements of 0.25 m have been recorded.

A major water supply dam south of Sydney is currently being undermined using a system designed to limit subsidence to about one tenth of the maximum. The mine has implemented an extensive monitoring programme which should provide valuable data in the future on the effect of mining on the overlying strata, including the ground water regime in that strata.