Heritage

Bondi Ocean Outfall Sewer (BOOS)

Item details

Name of item: Bondi Ocean Outfall Sewer (BOOS)
Other name/s: Main Northern Ocean Outfall Sewer
Type of item: Built
Group/Collection: Utilities - Sewerage
Category: Sewage Tunnel
Primary address: Blair Street, Bondi, NSW 2026
Local govt. area: Woollahra

Boundary:

UBD Edition 31 Map 258 C1. The physical and operational curtilage of the Main Northern Ocean Outfall Sewer includes the sewers, ventshafts, pumping stations and other associated structures.
All addresses
Street AddressSuburb/townLGAParishCountyType
Blair StreetBondiWoollahra  Primary Address
Blair StreetBondiWaverley  Primary Address
Northern end of Williams ParkBondiWoollahra  Alternate Address
Northern end of Williams ParkBondiWaverley  Alternate Address

Statement of significance:

The Main Northern Ocean Outfall, or Bondi Ocean Outfall Sewer (BOOS), was the first ocean outfall sewer of its type to be designed and built in the country. It is one of the most significant engineering structures in Australia. It was a marvel of surveying accuracy for its time. The surveying allowed for the lining of the sewer before the tunnelling was completed.

The BOOS reduced the volume of polluted waters entering the Harbour and improved the health of the city's residents by moving polluted waters off shore. The construction of the BOOS saw other advances in technology related to the removal of sewerage from the sewers, houses and water courses within the city. These included the improving design and construction of pumping stations to move the sewerage from low lying areas, construction and research into the safe removal of noxious gases from the sewers, better ways of treating raw effluent, advances in engineering methods and construction for tunnelling across waterways and many more.

The significance of the Sydney's sewerage systems primarily relates to its role in the growth of Sydney and the expansion of municipal services from the turn of the century to the present. The construction in these systems is evidenced in the sewage pumping stations, vents, pipes, tunnels and other associated works which display in their character, a gradual change in architectural style spanning the Federation, interwar and Post War periods. Many of these systems are still in use today with little change to their original fabric. In addition, the development of the major sewerage systems also represented a major advance in the protection of public health of Sydney by reducing the discharge of sewage from inner city areas into Port Jackson.

The system includes the sewers, ventshafts, pumping stations and other associated structures. Many of these features are of aesthetic and cultural significance and have landmark values. Some of these items include nineteen of the first twenty pumping stations, large brick sewer vents at Bondi, Glebe, Hyde Park and Bellevue Hill. It also includes the construction of the cavern which later housed the treatment plant which began partial operation in 1953.
Date significance updated: 05 Nov 01
Note: There are incomplete details for a number of items listed in NSW. The Heritage Branch intends to develop or upgrade statements of significance and other information for these items as resources become available.

Description

Designer/Maker: Public Works Department
Builder/Maker: Public Works Department
Construction years: 1880-1889
Physical description: The Bondi Scheme discharges at Ben Buckler at the Pacific Ocean near Bondi. It was constructed as an intercepting sewer to reduce the amount of sewage discharging to the Harbour via the earlier City Council sewers. The sewer rises from Ben Buckler to the major junction chamber at the corner of Oxford, Liverpool and College Streets, from which the main branch sewers extend to the City, Darlington, Newtown, Annandale, Leichhardt, Glebe and Balmain. Large sewers junctioning with the outfall sewer were constructed to provide reticulation for East Sydney, Paddington, Woollahra and Waverley. The Bondi sewer is a gravitational system and gradually rises as it extends inland. Consequently it can only serve land directly above itself. Therefore after the initial scheme was completed in 1889 a considerable portion of the sewage continued to flow into the Harbour. Over time low level pumping stations were added to collect sewage from such areas and pump it to the Bondi Sewer. The Bondi Sewer is oviform in shape and was constructed from brick. The dimensions of the main outfall are 2.4m x 2.2m and this reduces by decrements to 2.1m x 1.8m at the major Oxford and Liverpool Street junction. Other components of the sewer system include a number of large brick sewer ventshafts and Bondi Sewerage Treatment Plant
Physical condition and/or
Archaeological potential:
The system is in excellent condition, with most of the original features remaining due to the nature of the fabric.
Date condition updated:10 May 00
Modifications and dates: The system was extended to Balmain and Newtown during the late 1890's.
Further information: See Ben Buckler Ventshaft, Bellevue Hill Sewer Ventshaft, The Obelisk, Glebe Sewer Ventshaft, Bondi sewerage Treatment Plant
Current use: Sewerage main
Former use: Sewerage main

History

Historical notes: By 1859 Sydney's sewerage system consisted of five outfall sewers which drained to the Harbour. By the 1870's, the Harbour had become grossly polluted and an alternative means of disposing of the city's sewage was investigated. This led to the construction of the Main Northern Ocean Outfall Sewer and a southern sewer draining to a sewage farm at Botany Bay.

The Main Northern Outfall Sewer (BOOS) was the first ocean outfall sewer to be designed and built in Sydney. At the time when Melbourne was getting its first reticulated sewer, Sydney was diverting its existing sewers from Harbour outfalls to ocean outfall. It was a marvel of surveying accuracy for it's time which allowed bricking to commence before breakthrough of the tunnel. This system reduced the flow into the Harbour sewers, until the introduction of the electric pumping stations. This system was instrumental in reducing the pollution entering the Harbour.

The sewer was lined with brick. It is 2.4m x 2.2m diminishing to 2.1m x 1.8m at the junction chamber at the corner of junction of Oxford and College Streets. It is from this point that the main branches extended in northerly, westerly and south-westerly directions. Two sections of the system have pitched roofs at the junction of Oxford and College Streets and also at Taylor Square. A number of engineers who worked on the system later worked on other notable landmarks such as T. Keele (President of The Water Board in 1904) , L.A.B Wade (father of dams) and W.C. Bennett (Chief Engineer) who were also both Board Members.

It is now known that the large volume expansion chamber near the ocean was tunnelled from the ocean end so that the spoil did not need to be hauled to the surface nor trundled along the tunnel under Blair Street. This meant that the extended tunnel could not drain out seepage water. This was dealt with by digging a side drain from Bondi across to Rose Bay to help dry out the wetland/swamp which is now a golf course. The spoil was dumped at the bottom of the cliff face. The remnants of the ladderway by which miners descended was removed c.1990.

Historic themes

Australian theme (abbrev)New South Wales themeLocal theme
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 Peopling the continent-National Theme 2
4. Settlement-Building settlements, towns and cities Utilities-Activities associated with the provision of services, especially on a communal basis (none)-

Assessment of significance

SHR Criteria a)
[Historical significance]
By 1859 Sydney's sewerage system consisted of five outfall sewers which drained to the Harbour. By the 1870's, the Harbour had become grossly polluted and an alternative means of disposing of the City's sewage was investigated. This led to the construction of the Main Northern Ocean Outfall Sewer and a southern sewer draining to a sewage farm at Botany Bay.

The historical significance of the sewerage system primarily relates to its role in the growth of Sydney and suburbs and the expansion of municipal services from the from the early 1900's to the present. The construction of these systems is evidenced by the sewage pumping stations, vents and other associated works which display in their character, a gradual change in architectural style spanning the Federation, Interwar and Post War periods.
SHR Criteria c)
[Aesthetic significance]
The vast majority of the sewer is located underground. A section can be observed at the entrance to Bondi STP and at Lough Reserve in Double Bay.. It displays a high level of workmanship which is evident in the brickwork. Other features of the system include several large ornate brick sewer ventshafts at Glebe, Bellevue Hill and Bathurst Street in the city. These have substantial landmark values.
SHR Criteria d)
[Social significance]
The development of the main sewerage systems represented part of the advance in the protection of public health in Sydney by collectively reducing the discharge of sewage from Port Jackson via the city's early sewers and divert to the Pacific Ocean. As such the system is of high significance to the general community.
SHR Criteria e)
[Research potential]
Sewerage systems demonstrate a variety of construction styles ranging from sandstone blocks, solid rock and reinforced concrete. The construction of these systems contributed to our understanding of the development and use of these materials in Australia and reflects the technological change in construction to meet the increasing population of Sydney.

Bondi was a masterpiece of surveying accuracy which meant that brick lining was commenced even before tunnel "breakthrough". The Nepean Water Tunnel had been similarly completed by T.W. Keele, but being a water tunnel did not require internal brick lining.
SHR Criteria f)
[Rarity]
The sewer is unique as the first such system in Australia. Technically significant as it contains important information relating to the construction of earlier sewers.
SHR Criteria g)
[Representativeness]
Represents the first ocean outfall sewer to be built in Sydney. One of only a few oviform outfalls, but the only one discharging into the ocean.
Integrity/Intactness: Substantially Intact
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.

Listings

Heritage ListingListing TitleListing NumberGazette DateGazette NumberGazette Page
Heritage Act - s.170 NSW State agency heritage registerSydney Water Heritage Register 30 Jun 02   

Study details

TitleYearNumberAuthorInspected byGuidelines used
Sydney Water Heritage Study1996 Graham Brooks and Associates Pty Ltd  Yes
Sydney Water Heritage Study1996 Graham Brooks and Associates Pty Ltd  Yes
Quakers Hat Aqueduct1999 Godden Mackay Logan  Yes
Quakers Hat Aqueduct1999 Godden Mackay Logan  Yes
Bondi Ocean Outfall Sewer : National Trust Listing1999 J.M.Collocott  No
Bondi Ocean Outfall Sewer : National Trust Listing1999 J.M.Collocott  No

References, internet links & images

None

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

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Data source

The information for this entry comes from the following source:
Name: State Government
Database number: 4570662
File number: 003316


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