upper, canal, SCA, BHP, Billiton, Illawarra Coal, heritage, longwall mining, Nepean, Avon, Cordeaux, Cataract, reservoirs, LW409Appin, colliery, Sydney

Georges River - Cataract River - Woronora River - Nepean River - Waratah Rivulet - Woronora Catchment

upper canal, heritage, longwall mining, Nepean, Avon, Cordeaux, Cataract, reservoirs, LW409Appin, colliery, Sydney, SCA, BHP, Billiton, Illawarra Coal
LW409 - Simpsons Creek - SCA - Upper canal - Heritage site
" This 64 kilometer canal delivers about 20% of Sydney's daily water needs"
Appin Colliery Area 4, Longwall 409 - SCA Upper Canal - BHP Billiton Illawarra Coal The photographs on this page came into our possession recently. The Upper Canal installation is located approximately 50 metres downstream (west) of the most westerly and second aboriginal cave found on Simpsons Creek The huge pipe and concrete installations which carry the Upper Canal over Simpsons Creek eventually come into view as one follows the trail of longwall mining destruction caused by BHP Billiton Illawarra Coals down Simpsons Creek. We were informed that access to the pipe and structure was obtained by simply walking up a set of moss covered stone steps which lead to the base of the structure. It is possible at that point to take photographs with a telephoto lens of the cracks on the concrete structure. There was no sign to say this was a sensitive area. One crack adjacent to the concrete structure was 30 mm wide and can be seen on several on this page. The sandstone rock the structure sits on appears to be starting to fracture. This can also be seen on this page. Longwall mining damage continued along Simpson's Creek to the west of the canal and around the installation itself. Damage predictions BHP Billiton Illawarra Coals end of panel report indicates that the Longwall409 project was completed with less damage than was originally predicted which appears to have been minimal. In fact it suggests that there was little if any need to follow through and repair any damage which may have occurred. Judge for yourselves by viewing the information found on this page in conjunction with the content of Simpsons Creek

Simpsons Creek & Upper Canal
BHP Billiton Illawarra Coal Longwall LW409 runs adjacent to and at one point under the Sydney Catchment Authorities Simpsons Creek North Flow Facility. on the Upper Canal for a distance of 200 metres. The canal was built in the 1880's to carry water from the Nepean, Avon, Cordeaux and Cataract dams to Sydneys Prospect Reservoir. The whole Upper Canal and associated structures are listed on the state heritage register. The 64 kilometer canal delivers about 20% of Sydney's daily water needs via gravity. There is a concern that storm water can deliver Cryptosperidium and Guardia into the water flowing down the canal which has happened in the past. Adjacent unsewered communities, urbanisation, motor vehicles, trespassers and vandals can also contaminate the canal. To cover the canal wouldn't eliminate pollution entering via cracks in its walls. Typically the canal supplies 500 megalitres of water per day of a theoretical maximum of 650 megalitres. There has been considerable mining subsidence in recent years with BHP Billiton Illawarra Coals Longwall LW409 passing alongside the canal for a distance of five hundred meters of which two hundred meters passed directly under the canal at Simpsons Creek. Illawarra Coal mined previously mined beneath the Cataract Tunnel which feeds the Upper Canal when extracting Longwalls 401 - 408 in the 1990's. Surface subsidence of 600 mm was measured requiring rock bolting and propping of the tunnel.
Information obtained from Water Engineering Australia July 2010 and Mining Under the Upper Canal - an engineering and heritage challenge by Dr Maclaren North