View source for Nepean River

{{Short description|River in New South Wales, Australia}}
{{Use dmy dates|date=October 2020}}
{{Use Australian English|date=February 2013}}
{{Infobox river
| name                = Nepean River
| name_native         = {{Native name|xdk|Yandhai}}
| name_other          = Cowpasture River, Mittagong River, London River<ref name=gnb>{{NSW GNR |id=ujKqZxsyMn |title=Nepean River |date=19 October 1973 |}}</ref>
| name_etymology      = In honour of [[Evan Nepean]], in 1789<ref name=gnb/>
| image               = Aus nsw nepean river dsc05078.jpg
| image_size          = 
| image_caption       = Nepean River, Looking north towards [[Penrith, New South Wales|Penrith]], 2006
| mapframe          = yes
| mapframe-point    = none
| map_size            = 
| map_caption         = 
| pushpin_map         = 
| pushpin_map_size    = 
| pushpin_map_caption = 
| subdivision_type1   = Country
| subdivision_name1   = Australia
| subdivision_type2   = [[States and territories of Australia|State]]
| subdivision_name2   = [[New South Wales]]
| subdivision_type3   = Region
| subdivision_name3   = [[Sydney Basin]] ([[Interim Biogeographic Regionalisation for Australia|IBRA]]), [[Southern Highlands (New South Wales)|Southern Highlands]], [[Macarthur (New South Wales)|Macarthur]], [[Greater Western Sydney]]
| subdivision_type4   = District
| subdivision_name4   = [[Wingecarribee Shire|Wingecarribee]], [[Wollondilly Shire|Wollondilly]], [[Camden Council (New South Wales)|Camden]], [[City of Penrith|Penrith]], [[Hawkesbury Shire|Hawkesbury]]
| subdivision_type5   = City
| subdivision_name5   = [[Penrith, New South Wales|Penrith]]
| length              = {{cvt|178|km|mi}}
| width_min           = 
| width_avg           = 
| width_max           = 
| depth_min           = 
| depth_avg           = 
| depth_max           = 
| discharge1_location = 
| discharge1_min      = 
| discharge1_avg      = 
| discharge1_max      = 
| source1             = Mittagong Range
| source1_location    = near [[Robertson, New South Wales|Robertson]]
| source1_coordinates = {{coord|34|33|59|S|150|36|01|E}}
| source1_elevation   = {{cvt|766|m}}
| mouth               = [[confluence]] with the [[Grose River]] to form the [[Hawkesbury River]]
| mouth_location      = near [[Yarramundi, New South Wales|Yarramundi]]
| mouth_coordinates   = {{coord|33|36|32|S|150|41|58|E|display=inline,title}}
| mouth_elevation     = {{cvt|92|m}}
| progression         = 
| river_system        = [[Hawkesbury River|Hawkesbury]]-Nepean catchment
| basin_size          = 
| tributaries_left    = [[Erskine Creek]], [[Breakfast Creek (New South Wales)]], [[Warragamba River]], [[Glenbrook Creek]]
| tributaries_right   = [[Burke River (New South Wales)]], [[Cordeaux River]], [[Cataract River (Wollondilly)]]
| custom_label        = [[National park]]
| custom_data         = [[Blue Mountains National Park]]
| extra               = <ref name=bonzle>{{cite web |url=http://www.bonzle.com/c/a?a=p&p=209569&cmd=sp |title=Map of Nepean River, NSW |work=Bonzle Digital Atlas of Australia |access-date=24 February 2013 |archive-date=29 August 2016 |archive-url=https://web.archive.org/web/20160829060728/http://www.bonzle.com/c/a?a=p&p=209569&cmd=sp |url-status=live }}</ref>
}}
[[File:Aerial views of Nepean River between Douglas Park and Menangle, New South Wales, Australia.webm|thumb|Aerial views of Nepean River between Douglas Park and Menangle]]

The '''Nepean River'''{{needs-IPA}} ([[Darug language|Darug]]: '''Yandhai'''<ref name=gnb/>), is a [[Perennial stream|major perennial river]], located in the south-west and west of [[Sydney]], [[New South Wales]], Australia. The Nepean River, and, continuing by its downstream name, the [[Hawkesbury River]], almost encircles the metropolitan region of Sydney.

The headwaters of the Nepean River rise near [[Robertson, New South Wales|Robertson]], about {{convert|100|km}} south of Sydney and about {{convert|15|km}} from the [[Tasman Sea]]. The river flows north in an unpopulated water catchment area into [[Upper Nepean Scheme#Nepean Dam|Nepean Reservoir]], which supplies [[potable water]] for Sydney. North of the dam, the river forms the western edge of Sydney, flowing past the town of [[Camden, New South Wales|Camden]] and the city of [[Penrith, New South Wales|Penrith]], south of which flowing through the [[Nepean Gorge]]. Near [[Wallacia, New South Wales|Wallacia]] it is joined by the [[dam]]med [[Warragamba River]]; and north of Penrith, near [[Yarramundi, New South Wales|Yarramundi]], at its [[confluence]] with the [[Grose River]], the Nepean becomes the Hawkesbury River.

==Changes to the natural flow of the river==
The river supplies water to Sydney's five million people as well as supplying agricultural production. This, combined with increased pressures from land use change for urban development, means the river has been suffering significant stress.{{citation needed|date=September 2017}}

There are eleven weirs located on the Nepean River that significantly regulate its natural flow. The river has been segmented into a series of weir lakes rather than a freely flowing river and is also impacted by dams in the Upper Nepean catchment.<ref>{{cite web |title=Nepean River Subcatchment |publisher=Hawkesbury Nepean Catchment Management Authority |year=2006 |url=http://www.hn.cma.nsw.gov.au/topics/2050.html |access-date=31 January 2007 |archive-date=29 August 2007 |archive-url=https://web.archive.org/web/20070829130922/http://www.hn.cma.nsw.gov.au/topics/2050.html |url-status=live }}</ref>

The Wallacia Weir was initially built as a wooden weir for the [[John Blaxland (explorer)|John Blaxland]] [[flour mill]] at Grove Farm. The first Australian fishsteps were built when the current concrete weir was built at the beginning of the Nepean Gorge, an anticendant entrenched meander caused by the slow uplift during the [[Blue Mountains (New South Wales)|Blue Mountains]] [[orogeny]] carved down through the fifty-million-year-old [[Hawkesbury sandstone]].
[[File:Nepean River from Richmond Bridge.jpg|thumb|The Nepean River viewed from [[North Richmond, New South Wales]].]]
In the 1950s, the building of the [[Warragamba Dam]] across the steep gorge of the [[Warragamba River]], the Nepean's major tributary, intercepted the flow of the great bulk of its waters and diverted them to meet the needs of the growing Sydney metropolitan area, reducing the river to a shadow of its former self.<ref>{{cite web |title=Themes - The Nepean River |publisher=[[City of Penrith]] |url=http://www.penrithcity.nsw.gov.au/index.asp?id=223 |access-date=31 January 2007 |url-status=dead |archive-url=https://web.archive.org/web/20060909141239/http://www.penrithcity.nsw.gov.au/index.asp?id=223 |archive-date=9 September 2006}}</ref>

These dams and weirs have had a potent effect, blocking migratory native fish like [[Australian bass]] (also locally commonly known as perch) from much of their former habitat, and reducing floods and freshets needed for spawning. Nevertheless, the Hawkesbury/Nepean remains an important and popular wild bass fishery.

The luscious banks of the Nepean River provide a natural haven for local flora and fauna and a quiet location for local residents to relax. At [[Emu Plains, New South Wales|Emu Plains]], the western bank of the river provides a location for outdoor theatre productions on warm summer nights. The eastern bank at Penrith provides [[barbecue]] facilities and children's play equipment, as well as a wide pathway running for several kilometres for strolls along the riverbank. The eastern bank is also the home of the Nepean Rowing Club.

[[Wallacia Mandi]], a [[Mandaean Australians|Mandaeans]] [[mandi (Mandaeism)|mandi]] (temple) in [[Wallacia, New South Wales|Wallacia]], is located on the west bank of the Nepean River. Water from the Nepean River is pumped into baptismal pools at the mandi for [[ritual purification]].<ref>{{cite web | title=Mandaean Synod of Australia | date=2005-07-05 | url=https://mandaeansynod.org.au/aboutus.html | access-date=2024-07-18}}</ref><ref name="association">{{cite web | title=Our new Mandi - An Introduction | website=The Sabian Mandaean Association | date=2024-03-06 | url=https://www.youtube.com/watch?v=RHXdLXMZKkc | access-date=2024-07-18}}</ref><ref>{{cite web |title=The Mandaeans of Shepparton |website=Shepparton Interfaith Network |url=https://sheppartoninterfaith.org.au/?p=3878 |access-date=3 June 2023 |language=en-AU |date=6 June 2019 |archive-date=7 March 2023 |archive-url=https://web.archive.org/web/20230307233141/https://sheppartoninterfaith.org.au/?p=3878 |url-status=live }}</ref>

==History==

===Pre-European history===
{{More citations needed section|date=February 2013}}
[[Indigenous Australians|Aboriginal people]] used the river regularly, and their fish traps could be seen at [[Yarramundi, New South Wales|Yarramundi]] before sand and gravel mining redirected the river. [[Charles Darwin]] also wrote of people at [[Emu Plains|Emu Ford]], commenting on their skill with spears, while [[Watkin Tench]] of the [[Royal Marines]] also noted their use of spears, lines and nets to capture fish. The people of the Nepean region also regularly traded with people of the western plains via a route that Bell followed when he laid down an alternate route over the mountains, now called [[Bells Line of Road]].

Near Penrith, since 1971 numerous Aboriginal stone tools were found in Cranebrook Terraces gravel sediments deposited by the Nepean River 40,000 to 50,000 years ago, according to repeated, revised and corroborated [[Radiocarbon dating|radiocarbon]] and [[Thermoluminescence dating|thermoluminescence]] dating. At first when these results were new they were controversial. More recently in 1987 and 2003 dating of the same sediments strata has revised and corroborated these dates.<ref name=Attenbrow-2010>{{Cite book |last1=Attenbrow |first1=Val |year=2010 |title=Sydney's Aboriginal Past: Investigating the Archaeological and Historical Records |location=Sydney |publisher=UNSW Press |isbn=9781742231167 |page=152 |url=https://books.google.com/books?id=TDxldj_SLcYC&q=inauthor%3A%22Val%20Attenbrow%22&pg=PA152 |access-date=11 November 2013 |archive-date=23 September 2023 |archive-url=https://web.archive.org/web/20230923094622/https://books.google.com/books?id=TDxldj_SLcYC&q=inauthor%3A%22Val%20Attenbrow%22&pg=PA152 |url-status=live }}</ref><ref name=Stockton-Nanson-2004>{{Cite journal |last1=Stockton |first1=Eugene D. |last2=Nanson |first2=Gerald C. |date=April 2004 |title=Cranebrook Terrace Revisited |journal=Archaeology in Oceania |volume=39 |issue=1 |pages=59–60 |jstor=40387277 |doi=10.1002/j.1834-4453.2004.tb00560.x}}</ref><!-- citations for the previous three sentences of this paragraph --> A great many more artefacts made by people have been found in the region dating back to within the last 5,000 years. Karskens et al. have made an attempt to recover, integrate and map archaeological data of the area from both published and unpublished reports.<ref name=Karskens1>{{cite journal |last1=Karskens |first1=G |last2=Burnett |first2=G |last3=Ross |first3=S |title=Traces in a Lost Landscape: Aboriginal archaeological sites, Dyarubbin/Nepean River and contiguous areas, NSW, Australia (Data Paper) |date=2019 |journal=[[Internet Archaeology]] |issue=52 |doi=10.11141/ia.52.8 |doi-access=free |url=https://intarch.ac.uk/journal/issue52/8/ |access-date=18 December 2019 |archive-date=18 December 2019 |archive-url=https://web.archive.org/web/20191218155604/https://intarch.ac.uk/journal/issue52/8/ |url-status=live }}</ref><ref name=Karskens2>{{cite journal |last1=Karskens |first1=G |last2=Burnett |first2=G |last3=Ross |first3=S |title=Traces in a Lost Landscape, Data records |date=2016 |publisher=Open Context |doi=10.6078/M7CR5R8Z}}</ref>

===European settlement===
{{More citations needed section|date=February 2013}}
When the [[Kingdom of Great Britain|British]] colony was established at Sydney in 1788, the Governor, Captain Arthur Phillip, charted the coast 50&nbsp;km north to the mouth of the Hawkesbury and around 32&nbsp;km upstream till they were stopped by a waterfall, most likely at Hawkesbury Heights.<ref>{{cite book |author=Clark, C. M. H |author-link=Manning Clark |title=A History of Australia |volume=I, From the Earliest Times to the Age of Macquarie |publisher=[[Melbourne University Press]] |year=1988 |page=235}}</ref> Phillip named the river after Lord Hawkesbury, later titled [[Charles Jenkinson, 1st Earl of Liverpool]], President of the Privy Council Standing Committee on Trade.

Meanwhile, Lieutenant [[Watkin Tench]] set off to walk inland, west of Sydney. About {{convert|60|km}} inland, at the foot of the [[Blue Mountains (New South Wales)|Blue Mountains]], he discovered a large river which he named Nepean after [[Evan Nepean]], the Under Secretary of State at the Home Office and a close personal friend of Arthur Phillip.<ref>{{cite web |url=http://www.historyofparliamentonline.org/volume/1790-1820/member/nepean-evan-1752-1822 |title=NEPEAN, Evan (1752-1822), of Loders Court, Dorset |work=The History of Parliament: the House of Commons 1790-1820 |editor=Thorne, R |year=1986 |publisher=The History of Parliament Trust |access-date=30 March 2013 |archive-date=26 February 2012 |archive-url=https://web.archive.org/web/20120226080523/http://www.historyofparliamentonline.org/volume/1790-1820/member/nepean-evan-1752-1822 |url-status=live }}</ref> It took about three years to realise that the Nepean flowed into the Hawkesbury.

Nepean river was also one of the pivotal sites of the [[Hawkesbury and Nepean Wars]], fought between the [[Kingdom of Great Britain]] and local aboriginal clans in the late 1700s and early 1800s.<ref>{{Cite book |last=Connor |first=John |title=The Australian frontier wars, 1788–1838 |publisher=UNSW Press |location=Sydney |year=2002 |isbn=0-86840-756-9 |url=https://books.google.com/books?id=JWE5r39Ed1oC |access-date=26 April 2018 |archive-date=15 January 2023 |archive-url=https://web.archive.org/web/20230115113318/https://books.google.com/books?id=JWE5r39Ed1oC |url-status=live }}</ref>

During the 1820s, the Nepean district's most famous early settler, the landowner and physician Sir [[John Jamison]] (1776–1844), erected a [[Georgian architecture|Georgian]] mansion, called [[Regentville]] House, on the model estate which he had established on a rise overlooking the river, not far from the present-day city of [[Penrith, Australia|Penrith]]. Jamison is considered one of early Australia's most important political and agricultural pioneers. A fire devastated the house in the 1860s.

==Crossings==
Despite forming the effective western and south-western boundary of the metropolitan region of Sydney for its entire length, there are very few fixed crossings of the Nepean River. Going upstream, these comprise:

{| class="wikitable"
 ! {{nowrap|Crossing name}}<br><small>(Unofficial name)</small>
 ! Right bank crossing location
 ! Left bank crossing location
 ! Comments/use
 ! Image
|-
|Yarramundi Bridge ||align="center"|[[Yarramundi, New South Wales|Yarramundi]] ||align="center"|[[Agnes Banks]] || Carries the [[Springwood, New South Wales|Springwood]] Road ||align="center"|
|-
|Victoria Railway Bridge || rowspan="3" align="center" |[[Emu Plains]] || rowspan="3" align="center" |[[Penrith, New South Wales|Penrith]] || Completed in 1907, the bridge carries the electrified and duplicated [[Main Western railway line]]. ||align="center"|[[File:Penrith Australia.jpg|120px]]
|-
|[[Victoria Bridge, Penrith|Victoria Bridge]] || Completed in 1867 and listed on the [[NSW State Heritage Register]], the bridge initially carried [[Main Western railway line|rail]] and [[horse-drawn vehicle]]s, and now the [[Great Western Highway]], with a daily traffic volume of approximately 24,500 vehicles in 2009.<ref name="AECOM">{{cite web |date=29 June 2012 |title=Nepean River Green Bridge: Transport Study (Draft) |url=http://www.transport.nsw.gov.au/sites/default/files/b2b/publications/nepean_river_green_bridge_transport_study_june2012_draft.pdf |access-date=24 February 2013 |work=[[Aecom]] |publisher=[[Transport for NSW]] |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304041223/http://www.transport.nsw.gov.au/sites/default/files/b2b/publications/nepean_river_green_bridge_transport_study_june2012_draft.pdf |url-status=dead }}</ref>|| align="center" |[[File:Victoriabridgepenrith1.jpg|120px]]
|-
|[[Yandhai Nepean Crossing]]
|Completed in 2018, the bridge carries pedestrian and cycle traffic.
|
|-
|Regentville Bridge ||align="center"|[[Leonay]] ||align="center"|[[Regentville]] || [[M4 Motorway (Sydney)|M4 Motorway]], and in 2011, carried an average of 55,000 vehicles per day<ref name=AECOM/> ||align="center"|
|-
| ||colspan=2 align="center"|[[Wallacia, New South Wales|Wallacia]] || Carries the Silverdale Road ||align="center"|
|-
| ||colspan=2 align="center"|[[Brownlow Hill]] || Carries the Cobbitty Road ||align="center"|
|-
| ||rowspan=3 align="center"|[[Camden, New South Wales|Camden]] ||align="center"|[[Kirkham, New South Wales|Kirkham]] || Carries the Macquarie Grove Road, located adjacent to the [[Camden Airport (New South Wales)|Camden Airport]] ||align="center"|
|-
|Cowpasture Bridge ||align="center"|[[Elderslie, New South Wales|Elderslie]] || Carries road traffic on the Camden-[[Narellan]] Road ||align="center"|
|-
|Macarthur Bridge ||align="center"|[[Spring Farm, New South Wales|Spring Farm]] || Opened in 1973, this bridge is {{convert|1.12|km}} long and carries the [[Camden Valley Way]]. ||align="center"|[[File:Camden south NSW Australia 20070223.jpg|120px]]
|-
| ||rowspan=2 align="center"|[[Menangle, New South Wales|Menangle]] ||rowspan=2 align="center"|[[Menangle Park]] || Carries road traffic on the Menangle Road ||align="center"|
|-
| [[Menangle Railway Bridge]] || Built in 1864 under the direction of [[John Whitton]], this is the oldest surviving rail bridge in New South Wales; and carries the [[Main Southern railway line]] ||align="center"|[[File:Menangle Viaduct 4.jpg|120px]]
|-
| ||colspan=2 align="center"|[[Menangle, New South Wales|Menangle]] || Carries road traffic on the [[Hume Highway]] ||align="center"|
|-
|Douglas Park Bridge ||rowspan=2 colspan=2 align="center"|[[Douglas Park, New South Wales|Douglas Park]] || A pair of concrete bridges that carry road traffic on the [[Hume Highway]] ||align="center"|[[File:Douglas Park Bridge F5 Freeway.jpg|120px]]
|-
| || Carries road traffic on the Douglas Park Drive. ||align="center"|
|-
|Maldon Bridge ||rowspan=2 colspan=2 align="center"|[[Maldon, New South Wales|Maldon]] || Completed in 1980, the concrete beam bridge carries the [[Picton Road, New South Wales|Picton Road]]. ||align="center"|
|-
|Maldon Suspension Bridge || Completed in 1903 and listed on the [[NSW State Heritage Register]], the wooden [[suspension bridge]] carried road traffic, and is now closed to all traffic ||align="center"|[[File:Maldon Bridge 1903.jpg|120px]]
|-
|Pheasants Nest Bridge ||colspan=2 align="center"|[[Pheasants Nest]] || Carries road traffic on the [[Hume Highway]] ||align="center"|
|-
|}

== Floods in the Nepean district ==
{{More citations needed section|date=February 2013}}
[[File:NepeanRiver downsteam of Victoria Bridge after heavy rainfall in the catchment 2013 02 24.jpg|thumb|270px|right|Nepean River, downstream of [[Victoria Bridge, Penrith|Victoria Bridge]], after heavy rains, 2013]]
The first flood on record - apparently a small occurrence - was in 1795. Others followed in 1799, March & October 1806<ref>{{cite news |url=http://nla.gov.au/nla.news-article627063 |title=HAWKESBURY, MARCH 27. |newspaper=[[Sydney Gazette|The Sydney Gazette and New South Wales Advertiser]] |volume=IV |issue=159 |date=30 March 1806 |page=2 |via=National Library of Australia |access-date=20 November 2016 |archive-date=7 April 2024 |archive-url=https://web.archive.org/web/20240407091802/https://trove.nla.gov.au/newspaper/article/627063 |url-status=live }}<br />{{cite news |url=http://nla.gov.au/nla.news-article627314 |title=Classified Advertising |newspaper=[[Sydney Gazette|Sydney Gazette & New South Wales Advertiser]] |volume=IV |issue=189 |location=New South Wales, Australia |date=26 October 1806 |page=1 |via=National Library of Australia |access-date=20 November 2016 |archive-date=7 April 2024 |archive-url=https://web.archive.org/web/20240407091822/https://trove.nla.gov.au/newspaper/article/627314 |url-status=live }}</ref> and 1809. In 1810, after a series of major floods on the Hawkesbury, [[Lachlan Macquarie|Governor Macquarie]] proclaimed the ‘Macquarie Towns’ of [[Windsor, New South Wales|Windsor]], Richmond, [[Wilberforce, New South Wales|Wilberforce]], [[Castlereagh, New South Wales|Castlereagh]], and [[Pitt Town]] in an attempt to ensure that development was restricted to higher ground, free of flooding. The devastation caused by flooding in February 1817 prompted [[Governor Macquarie]] to issue a notice exhorting settlers, in the strongest possible terms, to build their residences above the established flood levels.<ref>{{cite news |url=http://nla.gov.au/nla.news-article2177134 |title=Sydney. |newspaper=[[Sydney Gazette|The Sydney Gazette and New South Wales Advertiser]] |volume=FIFTEENTH |issue=695 |date=15 March 1817 |page=3 |via=National Library of Australia |access-date=20 November 2016 |archive-date=7 April 2024 |archive-url=https://web.archive.org/web/20240407091809/https://trove.nla.gov.au/newspaper/article/2177134 |url-status=live }}</ref>

More flooding occurred in 1857 and twice in 1860, both February and May.<ref>{{cite news |url=http://nla.gov.au/nla.news-article12998801 |title=SERIOUS DAMAGE TO THE NEPEAN BRIDGE. |newspaper=[[Sydney Morning Herald]] |volume=XXXVIII |issue=5976 |date=1 August 1857 |page=5 |via=National Library of Australia |access-date=23 November 2016 |archive-date=7 April 2024 |archive-url=https://web.archive.org/web/20240407091737/https://trove.nla.gov.au/newspaper/article/12998801 |url-status=live }}<br />{{cite news |url=http://nla.gov.au/nla.news-article13036725 |title=THE FLOODS. THE NEPEAN. |newspaper=[[Sydney Morning Herald]] |volume=XLI |issue=6770 |date=16 February 1860 |page=6 |via=National Library of Australia |access-date=23 November 2016 |archive-date=7 April 2024 |archive-url=https://web.archive.org/web/20240407091944/https://trove.nla.gov.au/newspaper/article/13036725 |url-status=live }}<br />{{cite news |url=http://nla.gov.au/nla.news-article13040548 |title=ANOTHER DESTRUCTIVE FLOOD. |newspaper=[[Sydney Morning Herald]] |volume=XLI |issue=6842 |date=12 May 1860 |page=10 |via=National Library of Australia |access-date=23 November 2016 |archive-date=7 April 2024 |archive-url=https://web.archive.org/web/20240407091943/https://trove.nla.gov.au/newspaper/article/13040548 |url-status=live }}</ref>

The most devastating flood occurred in June 1867 with the Nepean River estimated to have reached {{convert|13.4|m}} in the river, and {{convert|27.47|m}} [[Australian Height Datum|AHD]]. This flood carried away the approaches to the recently built [[Victoria Bridge, Penrith|Victoria Bridge]]. Emu Plains, Castlereagh, and the lower parts of Penrith were all under flood, causing immense loss of property. Many houses were carried into the river by landslides. Many residents were forced to take refuge in public buildings such as the Penrith Hospital and the public schools. A major flood such as that of 1867 would cause inundation of over 16,000 dwellings and damage costing approximately A$1.4 [[1,000,000,000 (number)|billion]].<ref>{{cite web |title=Hawkesbury-Nepean Flood Damages Assessment |url=http://www.infrastructure.nsw.gov.au/media/16727/molino_stewart_hn_flood_damages_report_final.pdf |website=NSW Infrastructure |access-date=20 November 2016 |page=27 |archive-date=16 February 2017 |archive-url=https://web.archive.org/web/20170216014535/http://infrastructure.nsw.gov.au/media/16727/molino_stewart_hn_flood_damages_report_final.pdf |url-status=dead }}</ref>

There have been other notable floods since, particularly that of July 1900 and March 1914. Again there was much flooding of streets and loss of houses and property along the river.

1974 was another significant [[La Niña]] flood event.<ref>{{cite web |title=La Niña - Detailed Australian Analysis |url=http://www.bom.gov.au/climate/enso/lnlist/index.shtml |work=[[Bureau of Meteorology]] |publisher=Commonwealth of Australia |access-date=14 May 2011 |archive-date=28 December 2017 |archive-url=https://web.archive.org/web/20171228165657/http://www.bom.gov.au/climate/enso/lnlist/index.shtml |url-status=live }}</ref>

During the [[2021 New South Wales floods]], the Nepean River became overflowed, peaking at {{cvt|10|m|2}}, with [[Windsor Bridge (New South Wales)|Windsor Bridge]] submerging in its waters, leading to inundated homes and isolated animals in the surrounds.<ref>[https://www.abc.net.au/news/2021-03-21/sydney-weather-live-bom-evacuation-warnings-flooding/100019438 Sydney weather live: Evacuation warnings across Western Sydney and Mid-North Coast as Warragamba Dam overflows] {{Webarchive|url=https://web.archive.org/web/20210322032117/https://www.abc.net.au/news/2021-03-21/sydney-weather-live-bom-evacuation-warnings-flooding/100019438 |date=22 March 2021 }} by ABC News. 21 March 2021</ref>

== Mandaean ritual use ==
The [[Mandaean Australians|Australian Mandaean community]] in the [[Sydney metropolitan area]] regularly performs [[masbuta]] (baptism) rituals in the Nepean River,<ref>{{cite web |last=Smith |first=David Maurice |title=An Ancient Baptism in Sydney |website=Roads & Kingdoms |date=30 July 2015 |url=https://roadsandkingdoms.com/2015/ancient-baptism-sydney/ |access-date=30 October 2021 |archive-date=30 October 2021 |archive-url=https://web.archive.org/web/20211030063223/https://roadsandkingdoms.com/2015/ancient-baptism-sydney/ |url-status=live }}</ref> typically in and around [[Wallacia Mandi]].<ref>{{cite web | title=Mandaean Synod of Australia | date=2005-07-05 | url=https://mandaeansynod.org.au/aboutus.html | access-date=2024-07-18}}</ref>

== See also ==
{{stack|{{portal|New South Wales|Water|Environment}}}}
* [[List of rivers of Australia]]
* [[Rivers of New South Wales]]
* [[Upper Nepean Scheme]]
* [[Geography of Sydney]]

==References==
{{reflist|35em}}

==External links==
* [http://www.hn.cma.nsw.gov.au/ Hawkesbury-Nepean Catchment Management Authority] website
* [http://www.hn.cma.nsw.gov.au/topics/2050.html Nepean River Subcatchment] at the Hawkesbury-Nepean Catchment Management Authority website
* [http://www.hn.cma.nsw.gov.au/topics/2054.html Upper Nepean River Subcatchment] at the Hawkesbury-Nepean Catchment Management Authority website
* [http://meusepress.tripod.com/sydneyrivers.pdf Guide to Sydney Rivers site]

{{Blue Mountains topics |state=autocollapse}}
{{The Hawkesbury River |state=autocollapse}}
{{Waterways of Sydney |state=autocollapse}}
{{Rivers of the Sydney Basin |state=autocollapse}}
{{Rivers of New South Wales |state=autocollapse}}

[[Category:Nepean River| ]]
[[Category:Hawkesbury River]]
[[Category:Rivers of Sydney]]
[[Category:Macarthur (New South Wales)]]
[[Category:Southern Highlands (New South Wales)]]
[[Category:Rivers of the Blue Mountains (New South Wales)]]
[[Category:Hume Highway]]
[[Category:Rivers in Mandaeism]]