Pressure Tunnel and Shafts | NSW Environment & Heritage

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Pressure Tunnel and Shafts

Item details

Name of item: Pressure Tunnel and Shafts
Type of item: Built
Group/Collection: Utilities - Water
Category: Water Tunnel
Location: Lat: -33.8954122736 Long: 151.12979927
Primary address: , Potts Hill, NSW 2143
Local govt. area: Bankstown
Local Aboriginal Land Council: Gandangara
Property description
Lot/Volume CodeLot/Volume NumberSection NumberPlan/Folio CodePlan/Folio Number
LOT1446 DP132224
LOT142DP1576
LOT152DP1576
LOT162DP1576
LOT172DP1576
LOT1 DP187816
LOT7 DP30405
LOT1 DP613377
LOT2 DP642128
LOT1 DP665856
LOT1 DP744939
LOT1 DP799302
LOT1 DP812589

Boundary:

The physical boundary curtilage of the Pressure Tunnel is to be taken as a distance of 3 metres around the existing infrastructure (NB this is not necessarily all owned by Sydney Water). The infrastructure associated with this item includes the original fabric and archaeological evidence including but not limited to the tunnel, vertical shafts and buildings attached to the shafts. The visual curtilage is restricted to the shafts from which access may be gained. Most of the pipeline is located below ground.
All addresses
Street AddressSuburb/townLGAParishCountyType
 Potts HillBankstown  Primary Address
 WaterlooSydney  Alternate Address
 EnfieldStrathfield  Alternate Address
 BurwoodBurwood  Alternate Address
 BankstownBankstown  Alternate Address
 CanterburyCanterbury  Alternate Address
 AshfieldAshfield  Alternate Address
 MarrickvilleMarrickville  Alternate Address
 ErskinevilleSydney  Alternate Address
 PetershamMarrickville  Alternate Address
 ChulloraBankstown  Alternate Address

Owner/s

Organisation NameOwner CategoryDate Ownership Updated
Sydney WaterState Government27 Nov 98

Statement of significance:

The Pressure Tunnel is of high historical and technical significance as it represents a successful engineering response to the difficulties of increasing the volume of water from the Potts Hill Reservoir to the Pumping Station at Waterloo, a historically critical link in the water supply of Sydney. It is the third largest pressure tunnel in the world, representing a significant achievement in the provision of a dependable water supply by the Government and Water Board during the inter-war period.
Date significance updated: 19 Dec 01
Note: The State Heritage Inventory provides information about heritage items listed by local and State government agencies. The State Heritage Inventory is continually being updated by local and State agencies as new information becomes available. Read the OEH copyright and disclaimer.

Description

Designer/Maker: Water Board
Builder/Maker: Water Board
Construction years: 1921-1935
Physical description: Beginning at Potts Hill, the tunnel passes under the suburbs of Chullora, Bankstown, Enfield, Canterbury, Ashfield, Petersham, Marrickville, Erskineville, and Waterloo at a depth below ground level varying for 15m to 67m beneath high ground at Ashfield. Its maximum grade is 1 in 100, and its minimum is 1 in 2000. Its total length is approximately 16 kilometres.

The pipes are lined with sand-cement mortar and the space between the liners and walls of the tunnel is filled with concrete to support the liner against deformation from internal pressures and as a protection against corrosion. Its delivery capacity can be increased by booster pumps at Potts Hill.

Seventeen shafts were constructed along the Pressure Tunnel. Of these Shaft 1 is in Rookwood Road near Potts Hill Pumping Station. Shaft 17 is located at Waterloo at the former Central Workshops. Shafts 2, 3, 7, 8, 13 and 16 have all been filled. Shaft 5 is the dewatering shaft that is located at Therry St and discharges into the Cooks River. Shaft 11 is another dewatering shaft which discharges into Hawthorne Canal. Shaft 4 is located on Roberts Road, Shaft 12 on Chester St at Petersham, Shaft 14 on Station St at Newtown and Shaft 15 on Newton St. Shaft 6 (also referred to as Offtake Shaft No. 2) sees a change in tunnel levels. The Tunnel level was raised by 36m. Shaft 9 is also refered to as Offtake Shaft No. 3 and Shaft 10 is referred to as Offtake Shaft No. 3A. The Shaft structures were constructed at each shaft and are considered to be components of the Pressure Tunnel and shafts. The shaft structures or Pressure Tunnel buildings provide for access to each of the shafts and internal components.

The shafts are metal lined and there are eleven Pressure Tunnel buildings, the first located at Potts Hill and the final one being the Central Workshops. Other buildings are located along the western railway line at Newtown, at Weston St in Lewisham, Watson Ave Ashfield, and St Anne's Square at Strathfield South.
Date condition updated:22 Jun 00
Modifications and dates: The bituman lining was replaced cement lining between 1961- 63, as soon as the adjacent City Tunnel was complete.
Current use: Water supply from Potts Hill to Waterloo
Former use: Water supply from Potts Hill to Waterloo

History

Historical notes: Bankstown:
This area was selected for settlement by Governor Hunter, who named it Banks Town in honour of eminent botanist, Sir Joseph Banks. In 1795 George Bass and Matthew Flinders had explored the Georges River, named after King George III, the reigning monarch. They sailed along what would later be the southern boundary of the municipality. They reported their findings and were given land grants in the Georges Hall area. Bass received the first grant in 1798, of 100 acres in the vicinity of the present Hazel and Flinders Streets. He did not farm it, and eventually it reverted to the Crown. Flinders' grant was alongside Bass'. He bought more land, until he held 300 acres, but did not farm it. Lieutenant Shortland and Surveyor James Meehan also got grants. By 1799, 1200 acres on both banks of the river had been granted to marines and ex-convicts.

The area developed slowly, as it was isolated from both Sydney and Parramatta. After Liverpool Road was constructed in 1814 it began to develop rapidly, and settlements grew up along the road. Bushrangers were a problem, and in Bankstown's early days, two, Patrick Sullivan and James Moran, were hung on makeshift gallows on the site of the present Bankstown Water Tower. A few days several of their companions were also hung there. They were probably interred in nearby unconsecrated land.

In 1831 Michael Ryan was granted 100 acres in Bankstown, which included this site, and for many years the area was called Ryan's Paddock.

The Church of England School established here in 1862, becoming the first public school in 1868, but was moved to North Bankstown in 1913. The first post office opened in 1863, but closed in 1918 (Pollen & Healy, 1988, 19).

Water Supply Tunnel:
Investigation for a large pressure tunnel was begun in 1914, to assist the trunk mains between Potts Hill and Crown Street. The tunnel was to extend from Potts Hill Reservoir to the Waterloo pumping station, approximately 16 kilometres. To allow for maintenance and cleaning, it was designed as two cylindrical tubes, each 1.8 metres in diameter. It was approved by the Parliamentary Standing Committee on Public Works in 1919.

Trial bores were put down in 1921 and 1922. The first tests were conducted between Potts Hill No.1 and No.5, a length of 4 kilometres, but extensive rupturing of the lining occurred. Further fractrues developed during testing of the tunnel between shafts 6 and 9. The section of the Pressure Tunnel between shafts 1 and 5 was commissioned in 1929 due to the urgent need for water. In 1930 the Board approved lining the entire length of the tunnel with steel tube (interior diameter of 8'3"). The tubing allowed for internal securing of the individual sections of the tube. The annular space between the tube and the tunnel was filled with blue metal concrete. Due to lack of funds the lining of the pipe was ceased until 1933 when funds were raised to complete the job. The lining was completed by 1935. The internal lining of the pipes was done with bituman which was done in the factory during manufacture. In 1961 the tunnel was the third largest in the world.

In 1933 a Royal Commission into the failure of the internal lining was ordered by the government. Lining of the Pressure Tunnel was underway by this point but the Royal Commision determined responsibility of the failures. The report contained great details of pressure tunnels and failures around the world and led to an influx of qualified engineers to the Water Board of the time.

Historic themes

Australian theme (abbrev)New South Wales themeLocal theme
3. Economy-Developing local, regional and national economies Environment - cultural landscape-Activities associated with the interactions between humans, human societies and the shaping of their physical surroundings (none)-
3. Economy-Developing local, regional and national economies Health-Activities associated with preparing and providing medical assistance and/or promoting or maintaining the well being of humans (none)-
3. Economy-Developing local, regional and national economies Technology-Activities and processes associated with the knowledge or use of mechanical arts and applied sciences (none)-
4. Settlement-Building settlements, towns and cities Utilities-Activities associated with the provision of services, especially on a communal basis (none)-
4. Settlement-Building settlements, towns and cities Utilities-Activities associated with the provision of services, especially on a communal basis Providing drinking water-

Assessment of significance

SHR Criteria a)
[Historical significance]
The Pressure Tunnel is a key component of Sydney's water supply system whose function has remained unchanged since it was constructed.
SHR Criteria c)
[Aesthetic significance]
The tunnel is underground and can only be observed from the inside when dewatered.
SHR Criteria d)
[Social significance]
The Pressure Tunnel and shafts are socially significant as they provided large volumes of water to the growing population of Sydney and surrounding suburbs. It provided water to the population during periods of drought and is likely to be held in high regard by the community for the function it plays.
SHR Criteria e)
[Research potential]
The construction of the tunnel was delayed when the two tunnelling machine imported from England were unable to tunnel through the sandstone bedrock. The sandstone was far too hard for the cutting tools and manual labour was used instead. The fractures that resulted under full head provided a better understanding of the substrata and its properties.
SHR Criteria f)
[Rarity]
This item is rare in NSW. It is the third largest pressure tunnel in the world.
SHR Criteria g)
[Representativeness]
It is representative of the successful engineering response to the difficulties of increasing the volume of water from Potts Hill to Waterloo, and the provision of a dependable water supply during the inter-war period.
Integrity/Intactness: Internally the tunnels are substantially intact. The shafts are considerably altered.
Assessment criteria: Items are assessed against the PDF State Heritage Register (SHR) Criteria to determine the level of significance. Refer to the Listings below for the level of statutory protection.

Recommended management:

Manage the place and its significant components in accordance with the Heritage Council State Owned Heritage Asset Management Guidelines and the Minimum Standards of Maintenance and Repair in the NSW Heritage Regulations. Manage significant site elements in accordance with a Conservation Management Plan (CMP). If no CMP exists, consult with Asset Management Commercial Services with respect to commissioning a CMP. When commissioning a CMP, do so in accordance with the Model Brief for CMPs available on ConnectNet. Seek endorsement of the CMP from the Heritage Council of NSW. Works undertaken in accordance with a Heritage Council-endorsed CMP do not require further approval under the NSW Heritage Act. Involve heritage professionals as required under the terms of the CMP, or as otherwise determined necessary. Review CMP every 5 years or in a major change of circumstances, whichever is sooner. Review of a CMP should only be undertaken following consultation with Asset Management Commercial Services . When commissioning a CMP review, do so in accordance with the Model Brief for CMPs available on ConnectNet. Where no CMP is in place, or where works are outside the scope of the existing CMP, assess heritage impacts of proposed works in accordance with Sydney Water Environment Impact Assessment guidelines (e.g. undertake a Heritage Assessment and/or Statement of Heritage Impact as required, obtain Heritage Council approval as required). Consult with the Heritage Manager, Environment and Innovation, when major works are planned which affect items of State heritage significance. Undertake archival and photographic recording before major changes, in accordance with Heritage Council guidelines. Lodge copies of the archival record with the Sydney Water Archives and the NSW Heritage Office. Where the item is listed in a Local Environmental Plan Schedule of Heritage items, determine if works are exempt from approval under the LEP provisions. Where works are not exempt, obtain necessary approvals from the local council, in accordance with SWC EIA Guidelines.

Recommendations

Management CategoryDescriptionDate Updated
Recommended ManagementProduce a Conservation Management Plan (CMP) 
Recommended ManagementPrepare a maintenance schedule or guidelines 
Recommended ManagementCarry out interpretation, promotion and/or education 

Procedures /Exemptions

Section of actDescriptionTitleCommentsAction date
57(2)Exemption to allow workStandard Exemptions SCHEDULE OF STANDARD EXEMPTIONS
HERITAGE ACT 1977
Notice of Order Under Section 57 (2) of the Heritage Act 1977

I, the Minister for Planning, pursuant to subsection 57(2) of the Heritage Act 1977, on the recommendation of the Heritage Council of New South Wales, do by this Order:

1. revoke the Schedule of Exemptions to subsection 57(1) of the Heritage Act made under subsection 57(2) and published in the Government Gazette on 22 February 2008; and

2. grant standard exemptions from subsection 57(1) of the Heritage Act 1977, described in the Schedule attached.

FRANK SARTOR
Minister for Planning
Sydney, 11 July 2008

To view the schedule click on the Standard Exemptions for Works Requiring Heritage Council Approval link below.
Sep 5 2008

PDF Standard exemptions for works requiring Heritage Council approval

Listings

Heritage ListingListing TitleListing NumberGazette DateGazette NumberGazette Page
Heritage Act - State Heritage Register 0163015 Nov 02 2209709
Heritage Act - s.170 NSW State agency heritage register     

Study details

TitleYearNumberAuthorInspected byGuidelines used
Sydney Water Heritage Study1996130141Graham Brooks and Associates Pty LtdGRAHAM BROOKS AND ASSOCIATES PTY LTD 1 July 1996 Yes
Alexandra Canal Conservation Management Plan2004 NSW Department of Commenrce, Heritage Design Services  Yes

References, internet links & images

TypeAuthorYearTitleInternet Links
WrittenPollen, Francis & Healy, Gerald1988Bankstown entry, in 'The Book of Sydney Suburbs'

Note: internet links may be to web pages, documents or images.

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(Click on thumbnail for full size image and image details)

Data source

The information for this entry comes from the following source:
Name: Heritage Office
Database number: 5053868
File number: 130141; EF14/4354


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