Parramatta, Australia’s second oldest settlement, is often recognised as a city of “firsts” . Rarely acknowledged among these “firsts” is a structure that holds a handful of firsts and honours of its own. Parramatta Dam remarkably holds the title of being the first large dam to be constructed in Australia; the first arch dam to be built in Australia; the only arch dam built of masonry blocks and Roman cement; one of two arch dams built by mathematical process in the world; the only ashlar* masonry arch dam built in Australia; and the first of 13 arch dams built by Department of Public Works which received world wide attention in 1909. In 1997 it was declared as a National Engineering Landmark. Almost 160 years after the foundation stone was laid the dam still stands proudly, providing visitors and residents a beautiful swimming location in Lake Parramatta. The excellent condition of the dam is testament to the high quality engineering that went into its design and construction.
The need for a dam was a result of demands by residents of Parramatta for copious and quality drinking water. Drinking water was originally sourced from the Parramatta River weir at Marsden Street with water carts delivering water from the river to residential storage cisterns. By the 1840’s the town’s drinking water became a health risk because of pollution from tanneries, wool washing operations, the Female Factory, gaol, and Parramatta Hospital. The District Council petitioned the Legislative Council in 1848 and 1849 to provide funds to build a new reservoir. Funding was secured and two sites were put forward, Toongabbie Creek or Hunt’s Creek. The choice of the dam site became a furious factional fight and after considerable bitter debate work commenced in 1851 on land supplied by James Pye at Hunt’s Creek. John Stewart was awarded the tender for the construction project, however, differences between the contractor and the committee managing the work saw Stewart, and two subsequent builders give up their contracts. The project was again plunged into controversy. A new supervising committee was formed which accepted a fresh tender from Captain Percy Simpson who had designed an unusual circular dam. Simpson handed the design to civil engineer Mr E. O. Moriarty, with the building works awarded to Randall and Gibbons.
Often neglected is recognition to James Pye for ensuring the dam was completed. It was largely through Pye’s energy, determination and vision that the dam was actually completed. Although it took longer than expected, it was also due to Pye’s commitment that fresh water from the dam was eventually piped directly to Parramatta town in 1881.
The foundation stone for the dam was laid by Pye in June 1855. The dam was constructed of solid sandstone quarried from the creek. Each block was carefully dressed to accurate dimensions and laid in courses 0.6m high. The dam wall was 11 metres high and extended about 3.6m into the abutments of each bank. It was completed in September 1856. By 1898 the capacity of the dam could not cope with the growing demand for water and a decision was made to extend the height of the dam by 3.3 metres using Portland cement concrete. The dam continued to provide high quality water to Parramatta until 1916. In 1920s and 1930s the lake became a popular bathing and picnicking spot.
In 1997 the dam was recognised as a National Engineering Landmark. The plaque erected to mark this occasion reads as follows;
LAKE PARRAMATTA DAM
CONSTRUCTED TO A HEIGHT OF 11M IN 1856 AND RAISED TO 14M IN
1898, THIS FINE DAM SUPPLIED WATER TO PARRAMATTA UNTIL 1916. IT
IS THE FIRST LARGE DAM AND THE FIRST ARCH DAM TO BE
CONSTRUCTED IN AUSTRALIA. IT IS BELIEVED TO BE THE ELEVENTH
SINGLE ARCH DAM IN THE WORLD AND ONE OF THE FIRST TWO
DESIGNED MATHEMATICALLY. IMPORTANT PEOPLE ASSOCIATED WITH
IT WERE ENGINEERS P. SIMPSON, E.O. MORIARTY AND C.W. DARLEY,
AND THE CONTRACTOR W. RANDLE.
DEDICATED BY THE INSTITUTION OF ENGINEERS, AUSTRALIA
AND PARRAMATTA CITY COUNCIL, 1997.
In the “Report in Support of a Nomination for Lake Parramatta Dam to be Declared a National Engineering Landmark”, the factors cited that contributed to the cultural significance of the dam were;.
- The dam is listed by ANCOLD as the first large dam built in Australia. (Historic, scientific – rare)
- It is believed to be the only masonry arch dam in Australia. (Historic; scientific – rare)
- The dam is believed to be the eleventh earliest single arch dam constructed in the world since antiquity. (Historic; scientific- rare)
- It is believed to be the only masonry dam in the world to combine the use of Roman and Portland cements in the one structure. (Historic; scientific – rare)
- It is of very slender construction when compared with structures of similar age. (Historic; scientific – rare)
- It was part of one of the earliest urban water projects in Australia, and remained in that service for sixty years. (Historic; social; scientific- representative)
- Its design and construction involved three of the most significant public works operatives of the time: Captain Percy Simpson, E.O. Moriarty and W Randle. (Historic; scientific – associative)
- The design of the dam is thought to have been a precursor to the use of the ‘cylinder’ formula used by C. W. Darley in his later program of dam construction. (Historic; scientific – representative)
- The raising of its height in 1898 by C.W. Darley was part of one of the earliest arch dam construction programs in the world, and attracted appropriate international attention. (Historic; scientific – rare, associative)
- The raising of height is itself over a century old and forms a part of the evolution of dam wall construction without unduly diminishing the integrity of the original structure. (Historic; scientific – representative)
The quality of design and construction is demonstrated by the fact that the dam remains in excellent condition, able to withstand loadings caused by Probable Maximum Flood conditions. (Historic; scientific – representative, rare)
- The dam remains as the focus of an important social and recreational facility for Parramatta and surrounding district. (Historic; aesthetic; social- representative)
It shows how technology can be adapted to provide an amenity which is valued by local inhabitants for its beauty, tranquility and bird life. (Aesthetic, social – representative)
*Ashlar means stones hewn to rectangular shapes
Neera Sahni, Research Services Leader and Peter Arfanis, Archivist, Parramatta City Council, Heritage Centre – 2015
 Wyatt, Ken, Clarke, Michael, Heinrichs, Paul. Report in Support of a Nomination for Lake Parramatta Dam to be Declared a National Engineering Landmark. https://www.engineersaustralia.org.au/portal/system/files/engineering-heritage-australia/nomination-title/Lake_Parramatta_Dam_Nomination.pdf
 Kass, Terry, Liston Carol, McClymont, John. Parramatta A Past Revealed
 Jervis, James. Lake Parramatta. 1958. Parramatta Council File no. 48/16 (a)
Ash, R. and Heinrichs, P. Parramatta Single Arch Dam – From 1856 and Still Going Strong. First international and Eighth Australian Engineering Conference. 29 September – 2 October 1996, Newcastle, Sydney
“Lake Parramatta brochure” (PDF). City of Parramatta. Retrieved 28 September 2015, http://www.parracity.nsw.gov.au/your_council/news/plans/recreational/lake_parramatta_plan_of_management
Terry Kass et al, Parramatta, A Past Revealed, Parramatta City Council, 1996
Whitaker, Anne, Shaping a City: 150 years of Parramatta City Council. Parramatta City Council, 2012
Lake Parramatta, Vertical File, Local Studies and Family History Library, Parramatta Heritage and Visitor Information Centre
Photos, Local Studies photo collection, Parramatta Heritage Centre