Woronora - Penshurst Pipeline | NSW Environment & Heritage

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Woronora - Penshurst Pipeline

Item details

Name of item: Woronora - Penshurst Pipeline
Other name/s: Woronora Dam
Type of item: Built
Group/Collection: Utilities - Water
Category: Water Pipe
Location: Lat: 34 06 37 S Long: 150 56 15 E
Primary address: Woronora Dam, Woronora, NSW 2232
Local govt. area: Sutherland

Boundary:

The physical boundary and curtilage of the Woronora-Penshurst Pipeline extends to the boundary of SCA/Sydney Water land along the route of the pipeline. The curtilage includes the original pipeline and all infrastructure associated with the pipeline such as bridges, tunnels, valvehouses, flow metres, cross-connections and pumping stations. The SCA owns the first 200m of pipe immediately downstream of the dam. The remainder is owned by Sydney Water.
All addresses
Street AddressSuburb/townLGAParishCountyType
Woronora DamWoronoraSutherland  Primary Address

Owner/s

Organisation NameOwner CategoryDate Ownership Updated
Water NSWState Government 

Statement of significance:

The Woronora-Penshurst Pipeline is significant because of it's relationship with the Woronora Dam, the fifth of the water supply dams built as part of Sydney's water supply. Woronora Dam was completed in 1942 and is the only one of Sydney's water supply dams which is not part of the Upper Nepean/Warragamba/Shoalhaven interconnected system. The dam and pipeline were built with the objective of supplementing Sydney's water supply whilst the much larger Warragamba Dam was being constructed.

The Woronora - Penshurst pipeline is culturally significant as it supplies water from Woronora Dam to the areas of Sutherland, Cronulla, Engadine, Heathcote, Helensburgh, Stanwell Park and the areas just north of Georges River.

The pipeline is 27.1 km long and consists of 42 inch ( 1.07m) mild steel spirally welded pipes.
The pipeline has technical significance because of it's corkscrew construction method. At the time of construction only small width steel sheets were available and in order to obtain a large diameter pipeline these were welded together in a spiral technique.
Date significance updated: 15 Feb 07
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: MWS&D Board / PWD
Builder/Maker: Water Board
Construction years: 1936-1942
Physical description: Woronora Dam is the only one of Sydney's major water supply storage dams which is not primarily part of the Upper Nepean/Warragamba/Shoalhaven interconnected system. It has the smallest catchment area, 85 sq km, of any of the water supply dams. The Dam is located on the Woronora River, just downstream of it's confluence with the Waratah Rivulet, about 6 km northwest of the township of Waterfall.

Water is discharged from the lake via two 3 feet (0.9m) diameter pipes in the base of the dam, these lead to a valvehouse located at the bottum of the downstream face of the wall. The water then flows along a 16.1 mile (27 km) pipeline, consisting of 42 inch (1.07m) mild steel spirally welded pipes lined internally with 1 3/8 inch (34mm) cement mortar. The pipeline crosses the Georges River on the old railway bridge at Como and discharges into the two elevated Penshurst reservoirs.

The 27 km length of pipeline main was constructed in four sections. The first section commences at the outlet of the Woronora Dam and then follows the left bank of the Woronora River. It crosses the river on a concrete causeway and continues along the right bank to No. 1 tunnel, approximately 400 m in length, some 3.2 km from the dam. The line then follows Heathcote Creek to near it's junction with the Woronora River.

The second section follows the right bank of the Woronora River as far as No. 2 tunnel, 13.5 km from the dam, where it continues on to cross Forbes Creek. The tunnel is approximately 244 m long and had to be lined with concrete because of the poor strata encountered. The main crosses the Forbes Creek on a specially designed structure. A pressure valve is located at Forbes Creek to reduce the pressure on the main downstream. The section ends at Grand Parade, Sutherland, where 20 inch (508mm) and 18 inch (457mm) branches feed the Sutherland Reservoir.

In the third section from Grand Parade to Como the main is laid partly above ground and partly in trench and crosses under the railway line near Jannali in a concrete culvert. At the southern end of the railway bridgeover the Georges River, the 48 inch (1.22m) main bifurcates into two 24 inch (0.61m) mains which are carried across the river on brackets welded to the lower chord on each side of the bridge.

After passing over the Georges River the fourth section of the main reverts to 48 inch (1.22m) diameter and follows the eastern side of the railway line to Oatley. At this point it deviates and proceeds principally underground along streets to the intersection of Hillcrest Avenue and Laycock Road, Penshurst,whereby a 36 inch (0.91 m) branch runs to the Penshurst Reservoirs.
Physical condition and/or
Archaeological potential:
Good
Date condition updated:27 Aug 09
Modifications and dates: Originally camouflaged during WW2 against potential threat or saboutage. After this period it was painted silver and then in 1980 the pipelines were repainted green to blend in with native bushland.

A program of maintenance on the pipeline rectified leaking joints.
Further information: SCA owns the first 200m of pipe, immediately downstream of the dam. The remainder is owned by Sydney Water.
Current use: Water Supply Pipeline
Former use: Water Supply Pipeline

History

Historical notes: The Woronora Dam was the fifth of the water supply dams built as part of the development of Sydney's water supply, and represented the first occasion where the water supply was to be provided from somewhere other than the four dams of the Upper Nepean Scheme (i.e. Cataract, Cordeaux, Avon and Nepean Dams).

Construction of the Woronora Dam commenced in 1927, with the two objectives of providing a water supply for the Sutherland/Cronulla area, and supplementing the Upper Nepean Scheme whilst the Warragamba Dam was being built. The dam and pipelines were designed by the Metropolitan Water Sewerage and Drainage Board in conjunction with the PWD and it was the first dam built entirely by the Board, after the transfer of the construction division from the PWD.

The primary function of the Woronora Pipeline when first constructed was to convey water from Woronora Dam to Penshurst Reservoir. Consequently areas previously served by pumping could be supplied with gravitational water. Since it's construction however, expansion in the Sutherland Shire has lead to the pipeline being used to supply Sutherland and Cronulla, Engadine, Heathcote, Helensburgh, Stanwell Park, and the areas just north of Georges River.

The scheme adopted by the Board in 1925, for the development of the Woronora Catchment, was concerned with the supply of only the Cronulla and Sutherland areas, and provided for the construction of a low dam with a 15 inch (380mm) trunk main and pumping station. When the Board decided in 1929 to fully exploit the catchment for Metropolitan Supply, the amended scheme provided for a much higher dam and a larger diameter pipeline to Penshurst. Supply was given to Sutherland and Cronulla by the erection of a pumping station on the pipeline (opposite Heathcote), a reservoir near Heathcote Railway Station and other incidental works.

Financial difficulties that arose early in 1930 resulted in the suspension of operations, which were not resumed until 1936. The amended programme provided for a 48 inch (1.22 m) diameter pipeline. Further delays were experienced and it was not until 1940 that it was possible to accelerate progress with a view to completing work by June, 1941. However, the heavy demand for steel arising from the war created extreme difficulty in securing delivery of the necessary pipes and commissioning of the pipeline did not occur until November, 1942.

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)-
4. Settlement-Building settlements, towns and cities Towns, suburbs and villages-Activities associated with creating, planning and managing urban functions, landscapes and lifestyles in towns, suburbs and villages (none)-
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]
The Woronora-Penshurst Pipeline is historically significant because of it's relationship with the Woronora Dam, the fifth of the water supply dams built as part of Sydney's water supply. Woronora Dam was completed in 1942 and is the only one of Sydney's water supply dams which is not part of the Upper Nepean/Warragamba/Shoalhaven interconnected system. The dam was built with the objective of supplementing Sydney's water supply whilst the much larger Warragamba Dam was being constructed. The pipelines were constructed with the purpose of transfering water from the dam site on Woronora River, near Waterfall, to the Penshurst Reservoirs, whence the Cronulla/Sutherland area could be supplied with gravitational water.
SHR Criteria c)
[Aesthetic significance]
The pipeline was originally camouflaged during the second world war. It was repainted silver after the war period. Around 1980 environmental measures resulted in the pipes being repainted green to blend in with the natural bushland.

The pipeline also passes through an area which is now the Heathcote National Park.
SHR Criteria d)
[Social significance]
The Woronora - Penshurst pipeline is socially significant as it supplies water from Woronora Dam to the areas of Sutherland, Cronulla, Engadine, Heathcote, Helensburgh, Stanwell Park and the areas just north of Georges River and as such is likely to be held in high regard by the broad community for the function it serves.

The completion of the Woronora Dam was a significant step in the continuing process of providing reliable water supply to Sydney and sorrounding areas. It further served the purpose of providing an interim measure, when it was realised that the growth of Sydney would require a water supply augmentation of a magnitude which could only be met by the construction of a major dam on the Warragmba River.

The construction of the pipeline allowed for the career of Sir William Hudson to advance. He was the resident engineer on the Woronora Dam/Pipeline project and went on to be the Engineer-in-Chief of the Water Board and the first Commissioner of the Snowy Mountains Scheme.

The Woronora Dam and Pipeline also strengthened Sydney's defences During WW2 by supplying an independent and alternate supply to the Upper Nepean Scheme in case of emergency.
SHR Criteria e)
[Research potential]
The pipeline is 27.1 km long consisting of 42 inch (1.07m) mild steel spirally welded pipes. A corkscrew technique was used in order to obtain a large diameter pipeline, as only small width sheet steel was available at the time of construction. A lack of expansion joints has resulted in minor leakages along the length of the pipeline.

The pipeline did not have adequate expansion joints when built. This caused some leakage of joints at later stages.

The pipeline has numerous river and creek crossings along it's route. At Woronora River and Forbes Creek the pipeline crosses the water via single pipe aqueducts. At Georges River the pipeline birfurcates and crosses the water via the former Como Railway Bridge. This bridge is significant as it is a Whitton's Lattice Girder Bridge and was built in 1885. The pipeline birfurcates when it crosses the bridge in order to equalise the load on the structure. The bridge is no longer used by the railway and is now owned by Sydney Water. It is presently used only for pedestrian and bicycle access.

The pipeline also passes through a rock tunnel known as Dingo Tunnel.
SHR Criteria f)
[Rarity]
One of a number of water supply pipelines in Sydney.
SHR Criteria g)
[Representativeness]
Representative of water supply pipelines and of infrastructure associated with the Woronora Dam which is the only one of Sydney's water supply dams that is not part of the Upper Nepean/Warragamba/Shoalhaven interconnected system.
Integrity/Intactness: Considerably 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:

Recommended Management: Manage the place and its components in accordance with the NSW Heritage Office Management Principles and Guidelines for NSW Agencies. Recommended Management: Implement the Conservation Management Plan for Woronora Dam (Graham Brookes & Assoc., 2007). Recommended Management: Undertake environmental impact assessment (EIA) when planning works on the site (refer to SCA's EIA Policy). Recommended Management: Implement bushfire management plans for the Metropolitan Special Area. Recommended Management: Carry out annual condition inspections and report condition in SCA annual report. Recommended Management: Consult experienced heritage practitioners and the SCA's Planning and Assessment Team during the preparation and execution of works to the place. Recommended Management: Prepare a maintenance schedule for the item(s) in Maximo.

Listings

Heritage ListingListing TitleListing NumberGazette DateGazette NumberGazette Page
Heritage Act - s.170 NSW State agency heritage registerWoronora-Penshurst Pipeline002271   

Study details

TitleYearNumberAuthorInspected byGuidelines used
Sydney Water Heritage Study1996002271Graham Brooks and Associates Pty LtdGRAHAM BROOKS AND ASSOCIATES PTY LTD Yes

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: 4580022
File number: 002271


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