Bondi Ocean Outfall Sewer
From Wikipedia, the free encyclopedia
| Bondi Ocean Outfall Sewer | |
|---|---|
  Location of Bondi Ocean Outfall Sewer in east Sydney  Bondi Ocean Outfall Sewer (Australia) | |
| Location | Blair Street, North Bondi, Sydney, Australia |
| Coordinates | 33°53′09″S 151°16′53″E / 33.8858°S 151.2815°E |
| Built | 1880–1889 |
| Architect | Public Works Department |
| Owner | Sydney Water |
| Official name | BOOS (Bondi Ocean Outfall Sewer); Main Northern Ocean Outfall Sewer |
| Type | State heritage (built) |
| Designated | 15 November 2002 |
| Reference no. | 1623 |
| Type | Sewage Tunnel |
| Category | Utilities – Sewerage |
| Builders | Public Works Department |
The Bondi Ocean Outfall Sewer is a heritage-listed sewerage infrastructure at Blair Street, North Bondi, Sydney, Australia. The sewer line commences at the intersection of Oxford Street and College Street in Darlinghurst and then travels in a more-or-less easterly direction for 6.1 kilometres (3.8 mi) passing through a number of suburbs until it reaches Blair Street in North Bondi. It was designed and built by the Public Works Department between 1880 and 1889. It is also known as BOOS (Bondi Ocean Outfall Sewer) and Main Northern Ocean Outfall Sewer. The property is owned by Sydney Water.
By 1859 Sydney's sewerage system consisted of five outfall sewers which drained to Sydney Harbour. By the 1870s, 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.[1]
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 its 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.[1]
The sewer was lined with brick. It is 2.4 by 2.2 metres (7 ft 10 in by 7 ft 3 in) diminishing to 2.1 by 1.8 metres (6 ft 11 in by 5 ft 11 in) at the junction chamber at the corner of junction of Oxford Street and College Street in Darlinghurst. 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,[2] L. A. B. Wade (father of dams) and W. C. Bennett (Chief Engineer), who were also both board members.[1]
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.[1]
Description
The Bondi Scheme discharges at Ben Buckler into the Tasman Sea in North Bondi. It was constructed as an intercepting sewer to reduce the amount of sewage discharging to Sydney 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 2.4 by 2.2 metres (7 ft 10 in by 7 ft 3 in) and this reduces by decrements to 2.1 by 1.8 metres (6 ft 11 in by 5 ft 11 in) 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.[1]
The sewer is substantially intact.[1]
Modifications and dates
The system was extended to Balmain and Newtown during the late 1890s.[1]
Other components of the system developed over time include the Bondi Sewer Vent, Bellevue Hill Sewer Ventshaft, The Obelisk, Glebe Sewer Ventshaft, and Bondi Sewerage Treatment Plant.[1]
