South Sister St. Marys, Tasmania

South Sister Correspondence

forestry tasmania failures

Mr G Wilkinson
Chief Forest Practices Officer
Forest Practices Authority
30 Patrick Street
10 February 2006

Dear Mr Wilkinson

Subsidence over Jubilee Mine - South Sister Coupe NI114A

I write in support of the issues raised with you by Dr Frances Daily in her e-mail to you of 9 February, and to draw to your attention additional information relevant to those issues.

The information provided by Dr Daily regarding Forestry Tasmania Coupe NI114A at South Sister has not been considered in preparing Forest Practices Plan PWJ 0010, and is of substantial significance to the land stability and water values of the coupe and adjacent lands

Expert advice based on a fit of the underground workings of the Jubilee Mine with the surface topography of the coupe, indicates that subsidence exists within the proposed harvest area, as a result of the extraction of pillars during mining operations. Such subsidence has not previously been identified by Forestry Tasmania.

This morning I interviewed Mr Donald Smith of St Marys who worked underground in the Jubilee mine from the 1940s until its closure in 1959-60. He was engaged at one period in the extraction of pillars at the location identified as Site 8 in the map forwarded to you by Dr Daily, underneath the area of the Derrick's Marsh Track 'puddle' and adjacent swampy depression referred to by Dr Daily.

The map of the mine workings obtained from MRT shows pillar extraction in this location over an area approximately 6 pillars by 7 pillars. Pillars were left at 24 yard centres, with a drive between them of 12-14 feet. Accordingly, with an intervening drive of 12 feet, each pillar was 60 feet x 60 feet. The area over which pillars were extracted at site 8 was, therefore, about 148yds x 172yds, or 25456 sq yards, or 5.25 acres.

There were further areas of pillar extraction in the Jubilee, and at the Cardiff Mine. A variation to the Plan was advised only in the last few weeks, some 12 months after the certification of the Plan, due to the evidence sought and provided to Forestry Tasmania by local residents of further subsidence around the Cardiff site not identified by Forestry Tasmania.

Forestry Tasmania was unaware of the existence of the Jubilee Mine underlying the coupe until told of its existence by residents, a situation confirmed by the Planning Coordinator, Mr P Rosevears, in personal conversation on 11th February 2005. A 300acre abandoned and flooded coal mine, characterised by surface subsidence in the proposed harvest area, does not require symbolic exclusion zones, it requires a detailed and extensive geo-technical investigation over the entire area by an independent and qualified body such as MRT to ensure the safety of contractors and the protection of land stability and subsurface water systems.

I also draw to your attention and remind you of the map previously provided to you showing the extensive network of springs, seepage areas, soaks and marshes located by residents across the coupe, features not located by Forestry Tasmania in planning the coupe, and preparing the Plan. No response has ever been made to this evidence.

The matters raised by Dr Daily with regard to the Derrick's Marsh Track 'puddle', and the emergence of small springs, following the roading operation on the coupe, is a clear indication of the unforeseen consequences that can result from disturbance to the current equilibrium on the coupe, as a result of vibration, compaction, heavy vehicle movement and felling. No matter that these particular manifestations have no apparent immediate consequence in terms of water flow and land stability; within the context of this particular coupe they are worrying indicators of potentially more serious, and unforeseeable, consequences of the proposed harvest and cartage operations.

All experts in this matter are agreed on the one fact, the water system of the coupe is a subsurface system. As such, it requires site specific geo-technical assessment, not conjecture, speculation and estimates of water yield based on irrelevant evapotranspiration studies carried out in mainland locations.

Local residents have provided information regarding the existence of the Jubilee Mine, local residents supplied the evidence of the extent of subsidence around the Cardiff Mine, local residents mapped the network of surface water manifestations of the groundwater system of the coupe, now local residents have provided further evidence of subsidence associated with the Jubilee. It should also be recognised that it was local residents who obtained the necessary information regarding the unique lichen population of the coupe which resulted in yet another variation to the Plan. It was local residents who pointed out the variety of errors of dating in the original Plan of 4/1/05.

Forestry Tasmania has consistently failed to recognise, acknowledge and evaluate the subsurface of this coupe, both the underground water system and the underground coal mines. 'Out of sight, out of mind' has been its guiding principle.

It is residents who have repeatedly set in train and undertaken the necessary investigation to discover the physical characteristics of this site relevant to protection of the fundamental environmental values of water and land stability. Forestry Tasmania has failed to meet the Code requirements in these regards, and harvesting of the coupe should be stopped until an independent and expert geo-technical assessment is made of the coupe. Given the issues of groundwater and coal mining, it is self evident that MRT should be the agency of choice.

Just how much more new and substantial information regarding the physical characteristics of this coupe does the FPA want us to provide to indicate that the planning by Forestry Tasmania has not been appropriate to this particular coupe, however appropriate it may be to other more run of the mill coupes, not involving groundwater systems, coal mines, land slips, and nearby town water supplies? How many variations of the Plan are to be made as a result of new information supplied by local residents?

Just how impartial and independent of the forest industry is the umpire?

I look forward to your response to this further information.


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