View source for Upper Nepean Scheme

{{Short description|Series of dams and weirs in New South Wales, Australia}}
[[File:CordeauxDam.JPG|thumb|Wall of the Cordeaux Dam, one of the dams in the Upper Nepean Scheme]]

{{Use Australian English|date=October 2017}}
{{Use dmy dates|date=October 2017}}
The '''Upper Nepean Scheme''' is a series of [[dam]]s and [[weir]]s in the catchments of the [[Cataract River (Wollondilly)|Cataract]], [[Cordeaux River|Cordeaux]], [[Avon River (Wollongong)|Avon]] and [[Nepean River|Nepean]] rivers of [[New South Wales]], [[Australia]]. The scheme includes four dams and two weirs, and a gravity-fed canal system that feeds into a large storage [[reservoir]] to provide water to the [[Macarthur, New South Wales|Macarthur]] and [[Illawarra]] regions, the [[Wollondilly Shire]], and metropolitan [[Sydney]]. The four dams and associated infrastructure are individually listed on the [[New South Wales State Heritage Register]].<ref name="SHR Cataract"/><ref name="SHR Cordeaux"/><ref name="SHR Avon"/><ref name="SHR Nepean"/>

== History ==
By 1867, Sydney was outgrowing the water supply available from [[Botany Swamps]] and the [[Governor of New South Wales|Governor]] ([[John Young, 1st Baron Lisgar|Sir John Young]]) appointed a Commission to recommend a future water supply.<ref>{{cite news |url=http://nla.gov.au/nla.news-article13152526 |title=THE GOVERNMENT GAZETTE. |newspaper=[[The Sydney Morning Herald]] |volume=LVI |issue=9159 |date=28 September 1867 |access-date=22 May 2016 |page=7 |via=National Library of Australia}}</ref>
<!-- Commission members
[[John Smith (New South Wales politician, born 1821)|John Smith]] | M.D. | Professor of Physics | Sydney University 
[[Edward Orpen Moriarty]] | | Civil Engineer | Harbours and Rivers Navigation
[[Philip Francis Adams]] | | Deputy Surveyor General
Francis Henry Grundy | | Civil Engineer
[[Thomas Woore]] | |
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In 1869, the Commission recommended the Upper Nepean Scheme.<ref>{{cite news |url=http://nla.gov.au/nla.news-article60897166 |title=REPORT OF THE WATER SUPPLY COMMISSION. |newspaper=[[Empire (newspaper)|The Empire]] |issue=5607 |location=New South Wales, Australia |date=22 October 1869 |access-date=5 October 2016 |page=4 |via=National Library of Australia}}</ref> This comprised weirs on the Cataract and Nepean rivers, a [[Prospect Reservoir|storage reservoir at Prospect]] and {{convert|63.25|mi|km|order=flip}} of pipelines, tunnels, canals and aqueducts to bring water from the {{convert|347|sqmi|km2|order=flip}} catchment area to Sydney. Work on the Scheme began in 1880<ref>{{cite news |url=http://nla.gov.au/nla.news-article13443756 |title=THE WATER SUPPLY OF SYDNEY. |newspaper=[[The Sydney Morning Herald]] |issue=13,060 |date=10 February 1880 |access-date=22 May 2016 |page=6 |via=National Library of Australia}}</ref> and was completed in 1888.<ref name=Aird/>{{rp|pages=15–17}} The Scheme was a significant feat of engineering at the time of construction.

In June 1885 Sydney was in the grip of a severe drought and the Upper Nepean Scheme was incomplete. The Government accepted an offer from [[Clyde Engineering|Hudson Brothers]] to bridge the gaps and deliver {{convert|3|e6impgal|ML e6USgal|order=flip}} of water per day into Botany Swamps. Duplicating the entire length of the half built permanent scheme this became known as Hudsons' Temporary Scheme and was turned into the swamps on 30 January 1886.<ref name=Henry/>{{rp|64}}<ref>{{cite news |url=http://nla.gov.au/nla.news-article13610243 |title=THE TEMPORARY WATER SUPPLY. |newspaper=[[The Sydney Morning Herald]] |issue=14,931 |date=1 February 1886 |access-date=30 April 2016 |page=6 |via=National Library of Australia}}</ref> This emergency work was dismantled as the main scheme was completed.<ref name="Aird" />{{rp|pages=18–19}}

As originally built, the Upper Nepean Scheme was capable of supporting an estimated population of 540,000. By 1902, Sydney had a population of 523,000 and was again in the grip of a severe drought. A Royal Commission appointed to report on Sydney's water supply recommended a dam on the Cataract River and construction commenced in the same year. Dams were subsequently built on each of the Cordeaux, Avon and Nepean rivers, with the last being completed in 1935. Each dam includes a public picnic area.<ref name="Aird" />{{rp|pages=25–31}} In total, the four dams hold {{convert|483600|ML|impgal USgal|abbr=on}} and can safely provide <!-- {{convert|353,600|ML/d|impgal/d USga/d|abbr=on|lk=on}} --> {{convert|353|ML|e6impgal e6USgal|abbr=on}} per day.<ref name="Aird" />{{rp|page=268}}

The Scheme is now managed by the [[Sydney Catchment Authority]].

Further supplementary water supply is provided by a feed from the [[Shoalhaven Scheme]] through various pumps, pipes, cuts and diversions.

==Associated dams==

===Cataract Dam===
{{main|Cataract Dam}}
The [[Cataract Dam]] is a [[heritage register|heritage-listed]] [[gravity dam]] with an unlined side spillway extending from the left abutment. It is {{convert|183|ft|m|order=flip}} tall, {{convert|811|ft|m|order=flip}} long and holds {{convert|97190|ML|impgal USgal|abbr=on}} of water.<ref name="Aird" />{{rp|page=268}} Cataract Dam was the first dam built in the Upper Nepean Scheme, it was also first dam in Australia to use pre-cast moulded concrete blocks for the upstream face of the dam.<ref name="SHR Cataract">{{cite NSW SHR|5051469|Cataract Dam|fn=H08/00192; H99/00197, 125107|access-date=13 April 2012 }}</ref> The core of the dam consists of large {{convert|2|to|4.5|LT|t ST|2|lk=on|adj=on}} sandstone blocks, quarried onsite and [[cement]]ed together. The downstream face is of mass poured [[basalt concrete]], with a [[basalt]] facing. A readily accessible source of suitable rock was located some distance away at Sherbrooke, also known as Ferndale, situated near the top of [[Bulli Pass]]. To transport the basalt from the quarry to the dam construction site, a {{RailGauge|2ft|lk=on}} gauge steam tramway, {{convert|8.8|km|mi|abbr=on}} long, was constructed.<ref>{{cite journal |title=Construction Railways of the Upper Nepean Dams - Cataract Dam |author=Longworth, Jim |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |date=July 1993 |pages=163–174}}</ref> Dam construction began in 1902 and was completed in 1907, and the spillway was widened in 1915.<ref name="Aird" />{{rp|pages=27–28}} [[Ernest Macartney de Burgh]] was the supervising engineer for the project from 1904.<ref>{{cite web |url=http://www.adb.online.anu.edu.au/biogs/A080285b.htm |title=De Burgh, Ernest Macartney (1863 - 1929) |access-date=22 April 2007 |author=Antill, J. M. |work=[[Australian Dictionary of Biography]], Volume 8 |publisher=[[Melbourne University Press|MUP]] |year=1981 |page=266}}</ref> Poet [[Banjo Paterson]] wrote a satirical ballad "The Dam that Keele Built" about the politics behind the construction of Cataract Dam.<ref name="SCA_Cataract">{{cite web|title=Cataract Dam - Sydney Catchment Authority|url=http://www.sca.nsw.gov.au/dams-and-water/major-sca-dams/upper-nepean-dams/cataract-dam|access-date=11 March 2012}}</ref>

===Cordeaux Dam===
{{main|Cordeaux Dam}}
The [[Cordeaux Dam]] is a heritage-listed [[arch dam]] across the [[Cordeaux River]] with an unlined side spillway on the left abutment. It is {{convert|191|ft|m|order=flip}} high, {{convert|1327|ft|m|order=flip}} long and creates a reservoir which holds {{convert|93640|ML|impgal USgal|abbr=on}}. Construction began in 1918 and was completed in 1926<ref name="Aird" />{{rp|page=268}}<ref name="SCA_Cordeaux">{{cite web|title=Cordeaux Dam - Sydney Catchment Authority|url=http://www.sca.nsw.gov.au/dams-and-water/major-sca-dams/upper-nepean-dams/cordeaux-dam|access-date=11 March 2012|archive-date=30 April 2012|archive-url=https://web.archive.org/web/20120430213921/http://www.sca.nsw.gov.au/dams-and-water/major-sca-dams/upper-nepean-dams/cordeaux-dam|url-status=dead}}</ref> at a cost of [[Australian pound|A£]]945,000.<ref name="SHR Cordeaux"/> The wall consists of large sandstone blocks, quarried onsite and cemented together, faced with a combination of bluestone and sandstone concrete.<ref name="Aird" />{{rp|pages=28–29}} The dam featured a number of improvements in design and construction on the earlier-completed Cataract Dam. These included contraction joints between units of construction placed at intervals of {{convert|90|ft|m|order=flip}}; inspection galleries at upper and lower levels, together with piping for registering any ground water pressure.<ref name="SHR Cordeaux">{{cite NSW SHR|5051470|Cordeaux Dam|fn=H08/00191; H99/00197, 125220|access-date=29 September 2017}}</ref> The blue metal used in the construction of the dam was supplied from the Government Quarries at [[Kiama, New South Wales|Kiama]] and brought by rail to [[Douglas Park, New South Wales|Douglas Park]]. From here it was conveyed by aerial ropeway across the [[Nepean Gorge]] to an interchange on the eastern side where the material was transferred to a {{RailGauge|2ft}} gauge steam tramway to a point adjacent to the dam site.<ref>{{cite journal |title=Construction Railways of the Upper Nepean Dams - Cordeaux Dam |author=Longworth, Jim |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |date=October 1993 |pages=249–259}}</ref>

===Avon Dam===
{{main|Avon Dam}}
The [[Avon Dam]] is a heritage-listed arch dam across the [[Avon River (Wollongong)|Avon River]]; it is {{convert|237|ft|m|order=flip}} tall, {{convert|732|ft|m|order=flip}} long and its reservoir holds {{convert|146700|ML|impgal USgal|abbr=on}}. It has the largest capacity of all the dams in the Scheme. Construction of the [[New South Wales State Heritage Register|heritage-listed]] dam wall began in 1921 and was completed in 1927<ref name="Aird" />{{rp|page=268}}<ref name="SCA_Avon">{{cite web|title=Avon Dam - Sydney Catchment Authority|url=http://www.sca.nsw.gov.au/dams-and-water/major-sca-dams/upper-nepean-dams/avon-dam|access-date=11 March 2012}}</ref> at a cost of [[Australian pound|A£]]1,047,000.<ref name="SHR Avon">{{cite NSW SHR|5051468|Avon Dam|access-date=29 September 2017}}</ref> The dam construction and materials are the same as Cordeaux.<ref name="Aird" />{{rp|page=29}} All materials for construction were transported from [[Bargo, New South Wales|Bargo]] railway station on a specially built road, all the other dams in the scheme used rail transport.<ref name="SCA_Cordeaux"/> There were some light tramways constructed at the dam site, however it would appear that no locomotives were employed; skips and other items being moved by winch, horse or manpower.<ref>{{cite journal |title=Construction Railways of the Upper Nepean Dams - Avon Dam |author=Longworth, Jim |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |date=January 1994 |pages=14–19 }}</ref>

===Nepean Dam===
{{main|Nepean Dam}}
The [[Nepean Dam]] is a heritage-listed arch dam across the [[Nepean River]]; it is {{convert|269|ft|m|order=flip}} tall and {{convert|709|ft|m|order=flip}} long. Construction on the Dam began in 1926, construction was delayed for two years during the Depression, it was finally completed in 1935.<ref name="Aird" />{{rp|page=268}}<ref name="SCA_Nepean">{{cite web|title=Nepean Dam - Sydney Catchment Authority|url=http://www.sca.nsw.gov.au/dams-and-water/major-sca-dams/upper-nepean-dams/nepean-dam|access-date=11 March 2012}}</ref> The capacity is listed variously as <!-- Impgal missing -->{{convert|67730|to|81400|ML|impgal USgal|abbr=on}}.<ref name="SCA_Nepean" /><ref name="Aird" />{{rp|page=268}} The Nepean Reservoir has a small storage capacity in relation to its large catchment area of {{convert|319|km2}}. While its capacity is much the same as that of Cataract and Cordeaux Reservoirs, its catchment basin is two and a half times as extensive as Cataract and three and a half times as extensive as Cordeaux. The Nepean Reservoir therefore fills more rapidly and, under normal conditions, is drawn upon more freely than the other reservoirs. The dam is located at an elevation of {{convert|325|m}} [[Australian Height Datum|above sea level]] and the construction cost was [[Australian pound|A£]]2,062,000.<ref name="SHR Nepean">{{cite NSW SHR|5051477|Nepean Dam|fn=H08/00193; 125181; 13/03104|access-date=29 September 2017}}</ref>

Railway sidings were established on the [[Main Southern railway line, New South Wales|Main Southern railway line]] at a point between Bargo and [[Yerrinbool, New South Wales|Yerrinbool]]. Transport to the dam site was again by light railway, on this occasion of standard gauge. This avoided transhipment from the Government vehicles bringing materials from large commercial quarries, effectively making the line an extended privately owned siding. The line was {{convert|4|km|mi|abbr=on}} long through gentle countryside. Trains were worked by a variety of locomotives, including a former [[Steam trams in Sydney|Sydney Steam Tram]] Motor. Additionally, there was a system of narrow ({{RailGauge|610mm|disp=s}}) gauge lines in use at the dam construction site.<ref>{{cite journal |title=Construction Railways of the Upper Nepean Dams - Nepean Dam |author=Longworth, Jim |journal=[[Australian Railway History|Australian Railway Historical Society Bulletin]] |date=May 1994 |pages=137–153 }}</ref>

Additional work was carried out on the spillway between 1943 and 1947 to prevent scouring of the dam foundations.<ref name="Aird" />{{rp|page=31}}

== Gallery ==
<gallery widths="200px">
Image:Cataract_at_capacity.jpg|Cataract reservoir at full capacity, discharging through spillway
Image:Cataract_spillway.jpg|Detail of Cataract Dam spillway
Image:Cataract_outlet_works.jpg|Outlet works at Cataract Dam
Avon Dam plate.jpg|Avon Dam plate
Nepean Dam plate.jpg|Nepean Dam plate
</gallery>

==See also==
{{stack|{{portal|Water|New South Wales}}}}
*[[List of reservoirs and dams in Australia#New South Wales|List of reservoirs and dams in New South Wales]]
*[[Sydney Water]]
*[[Shoalhaven Scheme]]
*[[Upper Canal System]]
*[[Lower Prospect Canal Reserve]]
*[[Guildford West pipehead and water supply canal]]

==References==
{{Reflist|30em|refs=
<ref name=Aird>{{Cite book |author1=Aird, W. V.   |title=The Water Supply, Sewerage and Drainage of Sydney|date=1961|url=https://www.sydneywater.com.au/web/groups/publicwebcontent/documents/document/zgrf/mdq0/~edisp/dd_044331.pdf|publisher=[[Sydney Water|Metropolitan Water Sewerage and Drainage Board]]}}</ref>
<ref name=Henry>{{Cite book|author=Henry, F. J. J.|title=The water supply and sewerage of Sydney|date=1939|url=https://www.sydneywater.com.au/web/groups/publicwebcontent/documents/document/zgrf/mdq0/~edisp/dd_044330.pdf|publisher=[[Sydney Water|Metropolitan Water Sewerage and Drainage Board]]|access-date=30 April 2016|archive-date=9 April 2019|archive-url=https://web.archive.org/web/20190409190801/http://www.sydneywater.com.au/web/groups/publicwebcontent/documents/document/zgrf/mdq0/~edisp/dd_044330.pdf|url-status=dead}}</ref>
}}

=== Attribution ===
[[File:CC BY icon-80x15.png]] This Wikipedia article was originally based on the [http://www.environment.nsw.gov.au/heritageapp/ViewHeritageItemDetails.aspx?ID=5051469 ''"New South Wales State Heritage Register"''] published by the [[Government of New South Wales]] under [https://creativecommons.org/licenses/by/3.0/au/ CC-BY 3.0 AU] licence (accessed on 13 April 2012); and based on the [http://www.environment.nsw.gov.au/heritageapp/ViewHeritageItemDetails.aspx?ID=5051470 ''"New South Wales State Heritage Register"''] published by the [[Government of New South Wales]] under [https://creativecommons.org/licenses/by/3.0/au/ CC-BY 3.0 AU] licence (accessed on 29 September 2017); and based on the [http://www.environment.nsw.gov.au/heritageapp/ViewHeritageItemDetails.aspx?ID=5051468 ''"New South Wales State Heritage Register"''] published by the [[Government of New South Wales]] under [https://creativecommons.org/licenses/by/3.0/au/ CC-BY 3.0 AU] licence (accessed on 29 September 2017); and based on the [http://www.environment.nsw.gov.au/heritageapp/ViewHeritageItemDetails.aspx?ID=5051477 ''"New South Wales State Heritage Register"''] published by the [[Government of New South Wales]] under [https://creativecommons.org/licenses/by/3.0/au/ CC-BY 3.0 AU] licence (accessed on 29 September 2017).

==Further reading==
{{commons category|Upper Nepean Scheme}}
* Sydney Catchment Authority. [https://web.archive.org/web/20091013014812/http://www.sca.nsw.gov.au/dams-and-water/major-sca-dams/upper-nepean-dams Upper Nepean Dams] <!-- I'll get this tomorrow  -->
* WaterNSW - {{cite web|title=Celebrating 125 years of the Upper Nepean Scheme|url=https://www.waternsw.com.au/__data/assets/pdf_file/0013/114025/Celebrating-125-years-of-the-Upper-Nepean-Scheme-brochure.pdf|publisher=WaterNSW|access-date=2 October 2019}}

{{WaterNSW |state=collapsed}}
{{Waterways of Sydney|state=autocollapse}}

{{coord|-34.227699|150.744232|source:wikidata|display=title|format=dms|name=Broughtons Pass}}

[[Category:Upper Nepean Scheme| ]]
[[Category:Geography of Sydney]]
[[Category:Macarthur (New South Wales)]]
[[Category:Dams in New South Wales]]
[[Category:Sydney Water]]
[[Category:New South Wales State Heritage Register]]
[[Category:Nepean River]]