Woronora Dam | NSW Environment & Heritage

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Heritage

Woronora Dam

Item details

Name of item: Woronora Dam
Type of item: Built
Group/Collection: Utilities - Water
Category: Water Supply Reservoir/ Dam
Location: Lat: -34.1128167861 Long: 150.9313304830
Primary address: Woronora Dam Road, Waterfall, NSW 2233
Local govt. area: Sutherland
Local Aboriginal Land Council: Illawarra
Property description
Lot/Volume CodeLot/Volume NumberSection NumberPlan/Folio CodePlan/Folio Number
LOT1 DP709244
LOT1 DP830604

Boundary:

Lands in the ownership of the SCA as outlined in the CMP
All addresses
Street AddressSuburb/townLGAParishCountyType
Woronora Dam RoadWaterfallSutherland  Primary Address

Owner/s

Organisation NameOwner CategoryDate Ownership Updated
Water NSWState Government 

Statement of significance:

The Woronora Dam, constructed between 1927 and 1941, is the fifth and last of the water supply dams constructed prior to the Second World War to provide a secure water supply to satisfy the demands of industrial, commercial and residential development of metropolitan Sydney up to c1960. The Woronora Dam was specifically built to service metropolitan areas south of the Georges River.

The foundation and wall drainage systems, and the Stripped Classical architectural expression of the crest and valve houses, collectively continue to be integral elements of an Inter-war (c.1930s) era high, curved, gravity dam in New South Wales.

The scale of the use of mass concrete in the upper portions of the dam wall is unique in New South Wales for the period. The design of the spillway incorporating the zig zag weir wall and diversion channels are likely to represent an early and notable technological advancement in the design of such structures.

The Woronora Dam is part of a group (in conjunction with the Metropolitan Dams) of like structures which are the State's largest and most intact ensemble of large dams completed prior to the Snowy Mountains Hydro-Electricity scheme within a well defined geographical area.

The Dam contains in-situ items of Inter-war era water delivery technologies developed by the Water Board, such as lengths of iron discharge pipes, emergency roller gate, stopboards and penstocks which in consideration of their scale and integrity are rare examples of their types. The welded mild steel delivery pipeline (of which only a small section is included in the heritage curtilage) similarly represents a notable advance in construction technology for the period.

The site of the Woronora Dam contains remnants of the construction platforms, roadways blasted out of the hillside for plant and machinery, and the sites of the township specifically established for the construction of the Dam that collectively continue to evoke the era of the dam's construction, which in consideration of the scale and permanent nature of the works represent a notable achievement in civil engineering practice.

The dam is a regional landmark that has engendered beautification works undertaken from the 1950s for the general visiting public. The picnic areas in particular have strong associations with past management practices of the Water Board. The grounds of the dam are associated with the local and regional community of Sydney as a longstanding place of passive recreation.
Date significance updated: 10 Sep 09
Note: There are incomplete details for a number of items listed in NSW. The Heritage Division intends to develop or upgrade statements of significance and other information for these items as resources become available.

Description

Designer/Maker: G. E. Haskins, Chief Engineer, MWS & DB
Builder/Maker: Metropolitan Water, Sewerage and Drainage Board of NSW
Construction years: 1927-1941
Physical description: Woronora Dam now serves only the Sutherland/Cronulla/Heathcote areas directly, with cross-connections available to the Warragamba and Upper Nepean supplies. It has the smallest catchment area, at 85km2, of any of the SCA dams and is very small compared with the Warragamba catchment area of 9,050 km2.

Woronora Dam is located on the Woronora River, just downstream of its confluence with the Waratah Rivulet, about 6km northwest of the township of Waterfall. Woronora Dam is a long, curved gravity dam constructed with cyclopean masonry and mass concrete, the mass concrete only being used in the later stages of the construction of the dam.

Key dimensions and data are as follows:
Full supply level above sea level: 553 feet (169m).
Height of wall above foundation: 216 feet (66m).
Length of wall: 1,280 feet (390m).
Maximum width at foundation level: 183 feet (55.8m).
Width at crest: 20 feet (6.1m).
Volume of concrete in wall: 373,240 cu yards (285,000 cu metres).
Catchment area: 29 sq miles (85km2).
Lake area: 937 acres (380 hectares).
Greatest depth of water: 201 feet (61.3m).

The dam has a zig-zag spillway (to give greater discharge rate) 500 ft wide (152.5m), located some distance from the wall, discharging via a deep cutting through sandstone bedrock, lined with concrete at its lower end, to the river bed well below the dam wall. Both the cutting and the spillway are prominent and spectacular features of the dam. The entrance roadways cross the spillway cutting via two narrow concrete bridges.

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

Technically, Woronora Dam is on a par with Nepean Dam and is the last of the mass concrete gravity dams, some 60 to 80m high, built largely before the start of World War II (a new era in size and complexity commenced with the construction of Warragamba Dam in 1947). It is finished in a pronounced Stripped Classical style with Art Deco overtones and is a visual partner for the Nepean Dam, which preceded it. The upper and lower valve houses provide the main sculptural features of the dam and are strong visual features. The two water treatment and pumping station buildings located below the Dam wall visually detract from the quality of the view down the river.

When construction was completed, some half dozen of the better cottages were retained for the permanent maintenance staff but these have been progressively replaced with brick cottages between the 1960s and 1980s. One cottage, now used as the staff office, is 1960s in origin, with a terracotta tile clad, hipped gable roof and timber window and door frames. Three staff residences are virtually identical single-storey brick cottages with a gable roofs clad in concrete tiles, with integral garages and metal framed windows and doors. They appear to date from the late1970s or early 1980s. An older, timber-framed AC (fibro) clad building with a skillion roof is now disused but served previously as a site office and is believed to be the oldest building remaining. It is now vacant but is probably representative of the type and materials of the buildings erected during construction of the dam.

Extensive picnic areas are located on the eastern side of the Dam. There are shelter sheds, barbecues, hot water urns and well maintained toilets, all set out amongst attractive garden areas of parkland or grassed open space. The upper park includes mid-19th century plantings of Monterey Pine, a circa 1960s circular fernhouse, BBQs and, showing a growing concern for the use of water for the maintenance of these areas, various plantings of more drought-tolerant species such as succulents. Near the dam wall is another small park with a shelter. Plantings in this vicinity include more succulents, such as Yucca and Aloe, along with the Rock Orchid (Dendrobium speciosum) and Philodrendron. The immediate dam site contains several areas of wetlands at the edges of the main water body.

The physical curtilage includes the dam, all its associated buildings and structures plus any area of land above, below or in the vicinity of the dam which was utilised or affected by the construction of the dam and its subsequent operation. The precise location of this boundary on the ground will need to be determined by detailed site analysis.
Physical condition and/or
Archaeological potential:
Good
Date condition updated:27 Aug 09
Modifications and dates: In the 1980s and 1990s, a modern water filtration and pumping plant has been installed adjacent to the Dam, with a pumping plant in the valley on the downstream side of the dam. They are not in the ownership of the SCA.
Current use: Water Supply water storage
Former use: Water Supply water storage

History

Historical notes: The early growth of Sydney’s water supply followed the English (and European) practice of depending on supply from local perennially flowing rivers and streams, sometimes from behind a weir or small dam.

Australian conditions, however, are quite different from European conditions, and the eventual realisation that local supplies would always be inadequate led, in 1880, to the concept of harvesting water in the southern highlands, collecting it in major storage dams, and bringing it to Sydney by canals and pipelines. Thus, in 1888, the Upper Nepean Scheme came into being and, in later years, its progressive development followed with the construction of Cataract, Cordeaux, Avon and Nepean Dams, the latter being completed in 1935.

By that time, it was appreciated that the growth of Sydney would, in the not too distant future, require water supply augmentation of a magnitude which could be met only by the construction of a major dam on the Warragamba River.

Because of the engineering difficulties and the very high cost of that project, it was decided first to utilise the Woronora River, being the only other significant river close to Sydney and construct on it a dam of size comparable with the Upper Nepean Scheme dams, thus enabling the deferral of Warragamba.

Consequently, construction of 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 supply to the southern parts of the metropolitan area.

As a result of financial difficulties, the dam was planned in stages, with the first stage being a small dam comprising a 45 feet high (13.7m) overshot weir impounding 206 million gallons (937 megalitres). The design for this incorporated the preparation of the ground to enable the construction of the final dam at a later stage and all excavation and preparation of the foundations were done with the ultimate structure in view. A second weir at Engadine near the confluence of the Woronora River and Heathcote Creek provided a pumping pond from which water was pumped to a reservoir at Engadine. Owing to the intervention of the economic depression, the first stage was not completed until 1931 and work ceased at that point. In late 1935, construction recommenced and then continued until completion of the dam, 216 feet high (66m) impounding 15,792 million gallons (71,790 megalitres), in late 1941. When the dam and pipeline to Penshurst were completed as far as Engadine, the weir at Engadine was abandoned. It was later destroyed by explosives.

Although only 56km from Sydney, Woronora Dam was built by a day labour workforce which, in the tradition of the Upper Nepean Dams was housed in a local construction township at the dam site. The standard of these townships had improved with each successive dam and Woronora, being the last of the series, had the highest standard until the advent of the Warragamba township.

Some families went from Nepean to Woronora, then eventually moved on to Warragamba, but the tradition ended there, as no new major dams were built after that time.
When construction was completed, some half dozen of the better cottages were retained for the permanent maintenance staff, and these have since been replaced with modern cottages.

Extensive picnic areas have been provided at Woronora Dam. There are shelter sheds, barbecues, hot water urns, and well maintained toilets all set out amongst attractive gardens.

Woronora Dam is the only one of Sydney’s major water supply storage dams not part of the main Upper Nepean/Warragamba/Shoalhaven interconnected system, as it was developed to supply those southern parts of Sydney which were, at the time, beyond the effective reach of the Upper Nepean scheme. It now serves only the Sutherland/Cronulla/Heathcote areas. So great has been the population growth in recent years that Warragamba water, also, is now fed to the Sutherland/Cronulla area.

Historic themes

Australian theme (abbrev)New South Wales themeLocal theme
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 (none)-

Assessment of significance

SHR Criteria a)
[Historical significance]
In providing water for southern suburbs of metropolitan Sydney the Woronora Dam, in ensuring security of supply, contributed to the extensive residential and commercial development of Sutherland from the 1930s.

Woronora Dam was constructed over a period of ten years between 1927 and 1941, a protracted construction period which is directly related to the Great Depression and a period of government financial stringency. The completion of the Dam during this period was one of the major public works projects undertaken in the State.
SHR Criteria b)
[Associative significance]
The design and construction of Woronora Dam was undertaken by the Construction Branch of the Water Board. The construction of the Dam drew upon the knowledge and experience of a number of the engineers including Gerald Haskins (the first engineer-in-chief of the former Water Board), Stanley T. Farnsworth and (Sir) William Hudson (best known for his role in the Snowy Mountains Hydro Electricity Scheme).
SHR Criteria c)
[Aesthetic significance]
The wall of Woronora Dam is an engineering work imbued with a sense of high aesthetic value expressed through the long curved high wall set with the wide valley of the Woronora River. Upstream of the dam wall this setting is characterised by the broad expanse of the pool of water bordered by the crests of the valley sides. Downstream of the dam wall the setting is characterised by forested hillsides. Collectively this topography at times of high water level imparts a picturesque scene when viewed from select vantage points above and on the dam wall.

The design and finishes of the crest house and lower valve house in the Inter War Stripped Classical style were prepared by the engineers of the Water Board. The architectural detailing evokes a sense of monumentalism that is ideally suited to the context of a dam, and is not exhibited elsewhere on this scale.
SHR Criteria d)
[Social significance]
The dam wall and spillway is recognised by the National Trust of Australia (N.S.W.) as being a place which is part of the cultural environment of Australia, which has aesthetic, historical, architectural, archaeological, scientific, social significance for future generations, as well as for the present community of New South Wales.

The Woronora Dam is recognised by the Heritage Council of N.S.W. as a place which is of significance to New South Wales in relation to its historical, scientific, cultural, social, archaeological, natural and aesthetic values.

The grounds of the Dam are likely to be associated by members of the community with the construction township, in particular for the period of the Great Depression when considerable numbers of families who resided at the place during those turbulent years.
SHR Criteria e)
[Research potential]
The dam wall is an excellent late example of gravity dam construction in the Inter-war era in incorporating inspection galleries, contraction joints, and ground surface drainage system which demonstrate the principal characteristics of this technology at the time.

The use of mass concrete in the upper section of the wall is likely to represent a major innovation in terms of dam construction technology at the time.

The terraces and platforms adjoining the dam wall abutments demarcate the location of plant and equipment used in the construction of the Dam, in particular the location of the cableway head towers, and concrete mixing plant, which may potentially provide further insight into Inter-war era construction practices.

The hillside near the upper picnic area and area alongside the road of access were the sites of the original construction township. These areas retain a road formation, drainage lines, concrete platforms and dry packed walls from that era. The integrity is such that collectively these features may potentially provide further insight into the lifestyles of the employees that constructed the Dam.

The catchment area in being relatively untouched bushland in close proximity to a major urban area has a high potential for further research into natural ecosystems.
SHR Criteria f)
[Rarity]
The construction technique of mass concrete in the upper sections of the dam wall is a first in New South Wales in dam construction on this scale. It was a technique that came to be exemplified in the construction of the Captain Cook Graving Dock and Warragamba Dam.

The size of the dam is unusual given the primary reason behind its construction was the supply of the suburban areas south of the Georges River. Other comparable sized dams are located in the adjoining Metropolitan Catchment which service the greater metropolitan area of Sydney.

The design of the spillway weir with its zig zag wall and diversion channels is likely to be unique in New South Wales for the time of construction.

The use of a welded mild steel pipeline (the majority of the length of the pipeline is outside the scope of this report) to delivery the water to Penshurst is a first in New South Wales.

The Dam is one of two extant dams in New South Wales that incorporate extensive Inter War Stripped Classical architectural detailing in the crest wall and superstructures of the valve and crest house.

The crest and valve houses and inlet works retain original ironwork which represent a substantial repository of water supply delivery technology for the era.
SHR Criteria g)
[Representativeness]
Woronora Dam is representative of a type of gravity dam constructed in New South Wales by the Water Supply and Sewerage Branch of the Public Works Department and Water Board during the first half of the twentieth century. Key representative attributes of the Dam’s design and construction include the use of cyclopean masonry bedded in sandstone concrete in the lower section of wall, use of blue metal concrete in the wall facings, use of a spillway set way from the gravity wall, valve and crest houses attractively designed and finished to a high standard, the use of an array of upstream intakes to regulate the quality of water supply, the internal inspection gallery, the foundation drainage system, the contraction joints, and the drainage system.

The upgrading of the valves and ancillary monitoring and operating equipment is representative of modern day safe operating practice.

The construction technologies used at Woronora Dam are representative of dams constructed in New South Wales through the first half of the twentieth century. Key representative attributes include the use of cableways, the building of temporary camps to house labourers and tradesmen, building of semi-permanent cottages to house salaried staff, the construction of terraced platforms to for plant and machinery, mechanisation of concrete production, the construction of a purpose built road of access to transport men, supplies and materials from the nearest railhead to the construction site, the building of permanent infrastructure such as water supply for construction plant, men and horses, and the use of electricity to power plant and equipment.

The rehabilitation of tracts of land scarred in the construction processes employed at Woronora Dam through beautification works is representative of practices undertaken at other dams throughout New South Wales. Key representative attributes of this practice include utilising the former terraced construction platforms as picnic areas and lookouts, and utilising the former construction roads and tramway for vehicular access to the dam site and dam wall.

The practice of ongoing maintenance of the dam wall and pipeline after completion through surveillance provided by resident staff is representative of procedures undertaken at other dams and weirs constructed in New South Wales.

The provision of public amenity at the Dam is representative of the use of large water supply and irrigation dams in New South Wales as places for recreation by the greater community.
Integrity/Intactness: The Woronora Dam has a high level of integrity.
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 including the Minimum Standards of Maintenance and Repair. Recommended Management: Implement the Conservation Management Plan (Graham Brookes & Assoc., 2007). Recommended Management: Undertake environmental impact assessment (EIA) when planning works on the site (refer to SCA's EIA Policy). Prepare a Statement of Heritage Impact and gain S60 or S140 Heritage Office approval prior to undertaking any non-exempt works on the site. 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.

Recommendations

Management CategoryDescriptionDate Updated
Recommended ManagementReview 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
21(1)(b)Conservation Plan submitted for commentWoronora Dam - Conservation Management Plan (Fourth Draft)  
21(1)(b)Conservation Plan submitted for endorsementWoronora Dam CMP, October 2002 Jun 21 2005
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
21(1)(b)Conservation Plan submitted for endorsementJune 2010 revision - Final by Graham Brooks & Associates et. al. Jul 13 2011
21(1)(b)Conservation Plan submitted for commentRevised curtilage map submitted as draft for comment Aug 15 2011
21(1)(b)Conservation Plan submitted for endorsementRevised CMP (June 2010) submitted for endorsement Dec 16 2011

PDF Standard exemptions for works requiring Heritage Council approval

Listings

Heritage ListingListing TitleListing NumberGazette DateGazette NumberGazette Page
Heritage Act - State Heritage Register 0137818 Nov 99   
Heritage Act - s.170 NSW State agency heritage register 122339   
National Trust of Australia register      

Study details

TitleYearNumberAuthorInspected byGuidelines used
Sydney Water Heritage Study1996122339Graham Brooks and Associates Pty LtdGRAHAM BROOKS AND ASSOCIATES PTY LTD 1 July 1996 Yes

References, internet links & images

TypeAuthorYearTitleInternet Links
Tourism 2007Woronora Dam View detail
WrittenAird W. V.1961The Water Supply, Sewerage and Drainage of Sydney.
TourismAttraction Homepage2007Woronora Dam View detail
WrittenBeasley M.1988The Sweat of their Brows - 100 Years of the Sydney Water Board 1888 - 1988
WrittenGraham Brooks and Associates2007Woronora Dam Conservation Management Plan
WrittenGraham Brooks and Associates (GBA), D M Taylor Landscape Architects, Sydney Catchment Authority, NSW Government Architect's Office2010Woronora Dam Conservation Management Plan
WrittenJ. M. Collocott - Sydney Water Register1991Sydney Water Supply, Woronora Dam

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: Heritage Office
Database number: 5051466
File number: H06/00300


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