Dry and is likely to gradient of 19 (EarthTech 2003). prove or disprove the the swamp are scoured have caused relative contribution of still affected. Significant subsidence cracking noted pools. the cracking subsidence compared to below the swamp in Native Dog Creek observed and drought and natural Severely (EarthTech 2003). contributed to erosive processes. burnt during Cracking visible in exposed rock in middle drying of the 2001 of swamp bushfires. making it more susceptible to Flat Rock Extensive Subsidence History of bord and pillar and longwall Insufficient baseline No known Gully still exists. Swamp gullying and tilting of mining. monitoring data prior to remediation. Some vegetation erosion. swamp are mining (swamp vegetation has regenerated. (Waratah The 2001 bushfires the swamp, but not likely to have survey 2001 to 2003). Rivulet, to the same high intensity as Swamps 18 made the Woronora and 19. Monitoring and swamp more Catchment) assessment of causes of Mining of Longwall 8 commenced during susceptible collapse by mining October 2001. to natural companies and others Erosion gullying was first noticed in erosive following erosion February 2002. processes. Difficulties In 2003 subsidence cracks were noticed proving/disproving relative downstream in Waratah Rivulet. contributions of natural erosion, drought, flood, Mining reports suggest fracturing below fire and subsidence due lower end of Flatrock Swamp and possible to lack of baseline data changes to swamp bed gradients and flow (EarthTech 2003; Krogh paths (Mills & Huuskes 2004). 2004, Krogh, submitted; Evidence of natural erosive processes Tompkins & Humphreys acting in swamp prior to mining (Tompkins
Dry and scoured pools. Severely burnt during 2001 bushfires. is likely to have caused the cracking observed and contributed to drying of the swamp making it more susceptible to gradient of 19 (EarthTech 2003). Significant subsidence cracking noted below the swamp in Native Dog Creek (EarthTech 2003). Cracking visible in exposed rock in middle of prove or disprove the relative contribution of subsidence compared to drought and natural erosive processes. the swamp are still affected. Flat Rock Swamp (Waratah Rivulet, Woronora Catchment) Extensive gullying erosion. Subsidence and tilting of swamp are likely to have made the swamp more susceptible to natural erosive processes. History of bord and pillar and longwall mining. The 2001 bushfires the swamp, but not to the same high intensity as Swamps 18 and 19. Mining of Longwall 8 commenced during October 2001. Erosion gullying was first noticed in February 2002. In 2003 subsidence cracks were noticed downstream in Waratah Rivulet. Mining reports suggest fracturing below lower end of Flatrock Swamp and possible changes to swamp bed gradients and flow paths (Mills & Huuskes 2004). Evidence of natural erosive processes acting in swamp prior to mining (Tompkins Insufficient baseline monitoring data prior to mining (swamp vegetation survey 2001 to 2003). Monitoring and assessment of causes of collapse by mining companies and others following erosion Difficulties proving/disproving relative contributions of natural erosion, drought, flood, fire and subsidence due to lack of baseline data (EarthTech 2003; Krogh 2004, Krogh, submitted; Tompkins & Humphreys No known remediation. Gully still exists. Some vegetation has regenerated.
peat-swamp-subsidence.docx