MAIN OUTFALL SEWER
BROOKLYN AND LAVERTON NORTH AND TRUGANINA AND HOPPERS CROSSING AND WERRIBEE AND WILLIAMS LANDING, BRIMBANK CITY, HOBSONS BAY CITY, WYNDHAM CITY
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Statement of Significance
What is significant?
The Main Outfall Sewer was constructed in 1892-4 and was a vital link in the sewerage system of Melbourne which, when it was constructed in the 1890s, was the largest civil engineering project ever undertaken in Victoria. The Main Outfall Sewer consists of a semicircular brick or concrete lined channel (in places arched over to form a circular tunnel with an earth covering) and three brick arched aqueducts. The sewer was constructed by seven contractors employing 1300 workers and cost £240,748. During the 1880s the phenomenal growth of Melbourne led to a crisis in sanitation. The situation was exacerbated by the existence within the metropolitan area of many municipalities which would have to agree on any sewerage system. A Royal Commission recommended the formation of a Metropolitan Board of Works, comprised of commissioners from each of the local government authorities, with responsibility for both water supply and sewerage. Eminent British engineer James Mansergh was appointed to advise on a suitable system. At a time when most cities dumped their untreated wastes directly into rivers and the sea, Mansergh advised treatment of Melbourne?s sewage by broad irrigation with a capacity large enough able to deal with the expansion in population expected over 50 years. The system he conceived and which was implemented in only slightly modified form began with a water closet at every property which delivered the sewage by gravity through a network of underground sewers of increasing diameter to a steam pumping station at Spotswood (VHR 1555) where it was forced up wrought iron rising mains to Brooklyn to begin its 25 kilometre journey along the Main Outfall Sewer to the sewage farm at Werribee. As could be expected, the Main Outfall Sewer has had much repair and replacement of fabric over the last century and its function has now been entirely replaced by the Western Trunk Sewer. Nonetheless, there is still extensive original fabric remaining within its easement.
How is it significant?
The Main Outfall Sewer is of historical and scientific (engineering) significance to the State of Victoria.
Why is it significant?
The Main Outfall Sewer is historically important as an artefact of the process of development of Melbourne into a modern metropolis. The decision in 1890 to build a sewerage system with a capacity well in excess of the contemporary population was far sighted. The project not only addressed an existing sanitary crisis, but also enabled expansion of the city into new areas because the ?downstream? sewerage infrastructure was of sufficient capacity. Unlike the rest of the system which is underground and out of sight, the Main Outfall Sewer is a visible manifestation of the entire system. The Main Outfall Sewer is also a tangible link with the formation of the Melbourne Metropolitan Board of Works whose role as the unifying force for major infrastructure projects in Melbourne over the last century is of enormous historical importance. The construction of the system is all the more remarkable because, although conceived during the years of the 1880s Boom, its completion was achieved during the years of the catastrophic 1890s Depression.
The Main Outfall Sewer is of scientific (engineering) importance as a major link in the most extensive engineering project undertaken in Victoria to that date. The concrete and brick open and covered sewer is a fine example of the technology of the period, exhibiting a high level of integrity. The three major red brick aqueducts over Kororoit Creek, Skeleton Creek and the Werribee River are excellent examples of multi-spanned, arched masonry bridges.
MAIN OUTFALL SEWER - HistoryContextual History:History of Place:
The part underground and above ground sewer was constructed in 1896-97 as part of the Melbourne Sewerage Scheme by the recently formed Melbourne and Metropolitan Board of Works. In the 1960s concrete covered viaducts were erected across Koroit & Skeleton Creek and the Werribee River to replace the brick and bluestone open channeled viaducts. The sewer ceased operating in the 1990s.
MAIN OUTFALL SEWER - Permit ExemptionsGeneral Exemptions:General exemptions apply to all places and objects included in the Victorian Heritage Register (VHR). General exemptions have been designed to allow everyday activities, maintenance and changes to your property, which don’t harm its cultural heritage significance, to proceed without the need to obtain approvals under the Heritage Act 2017.Specific exemptions may also apply to your registered place or object. If applicable, these are listed below. Specific exemptions are tailored to the conservation and management needs of an individual registered place or object and set out works and activities that are exempt from the requirements of a permit. Specific exemptions prevail if they conflict with general exemptions. Find out more about heritage permit exemptions here.Specific Exemptions:
1. All exempted alterations are to be planned and carried out in a manner which prevents damage to the fabric of the registered place or object, except those listed below.
2. Should it become apparent during further inspection or the carrying out of alterations that original or previously hidden or inaccessible details of the place or object are revealed which relate to the significance of the place or object, then the exemption covering such alteration shall cease and the Executive Director shall be notified as soon as possible.
3. If there is a conservation policy and plan approved by the Executive Director, all works shall be in accordance with it.
4. Nothing in this declaration prevents the Executive Director from amending or rescinding all or any of the permit exemptions.
5. Nothing in this declaration exempts owners or their agents from the responsibility to seek relevant planning or building permits from the responsible authority where applicable.
* all new sewerage, water supply and drainage works [within the sewer reserve that do not materially impact on the brick and concrete sewer], provided that plans are given to the Executive Director in advance of works
* repairs and maintenance which replace like with like
* construction and maintenance of a recreational trail including,
- emergency and safety works including collapsing and backfilling sections of covered and buried sewer where structure is unsafe and making safe manhole and inspection openings.
- installation of safety measures in sections of open sewer such as step irons, ladders and drainage systems and fencing
- demolition and removal of redundant or unsafe buildings and structures including ventilation stacks and the old depot site at Princes Highway
- removal of trees and vegetation where required, pest and weed control
- repair, replacement and new construction of fences and gates
- removal of hard and soft rubbish including piles of soil, screenings and road waste or modification works as required
- protection, maintenance and relocation of utility assets within the sewer reserve
- hard and soft landscaping including landforming
- erection of directional and interpretative signage
- modification of the sewer at road crossings for use as underpasses where feasible including opening of covered sections of sewer and backfilling sewer for access ramps
- removal of the sewer at Doherty’s Road to allow a new culvert underpass
- construction of overpass structures as required provided that plans are given to the Executive Director in advance of works
- strengthening of MOS road crossings as required
- lighting of MOS conduit for underpasses
MAIN OUTFALL SEWER - Permit Exemption Policy
The whole of the Main Outfall Sewer is a vitally important component of the sewerage system constructed to service Melbourne metropolitan area at the end of the nineteenth century. The elements that characterise the entire sewer are open brick lined channels, open concrete channels, covered brick lined channels, brick aqueducts, brick road bridges, concrete road bridges. It is intended that the sewer should be retained and conserved in such a condition that it is able to illustrate its function and construction. Since its replacement by the Western Trunk Sewer, the Main Outfall Sewer's function has been made redundant and instead the reserve will be mainly used as a recreational trail. It is intended that there will be agreement between the owners, managers and Heritage Victoria to ensure that in making safe the sewer, evidence of its existence will not be swept away. Instead, safety and repair work will be undertaken to an agreed methodology which will ensure public safety, minimise negative effect on the cultural heritage values and maximise potential for interpretation of those values. Until such time as this agreement is formalised into a permit exemption, the general exemptions listed below should remain in force.
Over recent years the sewer reserve has been used for the dumping of hard and soft rubbish, and road waste. As well, weeds and vegetation, including trees, have been allowed to proliferate such that their root systems affect the structural integrity of the sewer. The removal of these threats should be encouraged.
While ensuring that construction of the recreational trail and day to day maintenance of the sewer is enabled without a permit, it is still intended that any major construction or demolition which affects the cultural heritage significance of the structure of the sewer be subject to the permit process, except as listed below.
Main Outfall SewerHobsons Bay City
MMBW Brooklyn Pumping StationHobsons Bay City
Bluestone Bridge over Kororoit Creek CreekHobsons Bay City