Editing Swan River (Western Australia) (section)

==History==
{{see also|Swan River Colony}}
[[File:Vlamingh ships at the Swan River, Keulen 1796.jpg|thumb|''[[Willem de Vlamingh]]'s ships, with black swans, at the entrance to the Swan River, Western Australia'', coloured engraving (1726), derived from an earlier drawing (now lost) from the de Vlamingh expeditions of 1696–97]]
[[File:Battye freycinet swanriver lg.jpg|thumb|right|The first detailed map of the Swan River, drawn by François-Antoine Boniface Heirisson in 1801]]

The river was named {{lang |nl |Swarte Swaene-Revier}}<ref name="Seddon et al.">{{cite book |last1=Seddon |first1=George |author1-link=George Seddon (academic) |last2=Ravine |first2=David |name-list-style=amp |title=A City and Its Setting |year=1986 |publisher=Fremantle Arts Centre Press |isbn=978-0-949206-08-4 |url-access=registration |url=https://archive.org/details/cityitssetting00sedd |oclc=1029292438 |access-date=2020-10-12 }}</ref> by Dutch explorer, [[Willem de Vlamingh]] in 1697, after the famous [[black swan]]s of the area. Vlamingh sailed with a small party up the river to around [[Heirisson Island]].<ref>See also the 1780 usage of the name Black Swan River in – {{Citation |author1=Harmer, T. (17..-18 |author2=graveur). Graveur |title=Plan of the island Rottenest lying off the west coast of New Holland; Black Swan river on New Holland opposite Rottenest island / from Vankeulen; writing by T. Harmar | date=1780 |publisher=A. Dalrymple |url=http://trove.nla.gov.au/work/84349 |access-date=27 December 2013}}</ref> A French expedition under [[Nicholas Baudin]] also sailed up the river in 1801.<ref name="pér09" />{{rp|138–145}}

Governor Stirling's intention was that the name ''Swan River'' refer only to the watercourse upstream of the Heirisson Islands.<ref name="Seddon et al." /> All of the rest, including Perth Water, he considered estuarine and which he referred to as ''Melville Water''. The Government notice dated 27 July 1829 stated "the first stone will be laid of a new town to be called 'Perth', near the entrance to the estuary of the Swan River."{{quote without source |date=March 2025}}

Almost immediately after the Town of Perth was established, a systematic effort was underway to reshape the river. This was done for many reasons:
* to alleviate flooding in winter periods;
* improve access for boats by having deeper channels and jetties;
* removal of marshy land which created a mosquito menace;
* enlargement of dry land for agriculture and building.

Perth streets were often sandy bogs which caused Governor [[James Stirling (Australian governor)|James Stirling]] in 1837 to report to the Secretary of State for Colonies:{{quote without source |date=March 2025}}
{{blockquote |text=At the present time it can scarcely be said that any roads exist, although certain lines of communication have been improved by clearing them of timber and by bridging streams and by establishing ferries in the broader parts of the Swan River [...]. }}

Parts of the river required dredging with the material dumped onto the mud flats to raise the adjoining land. An exceptionally wet winter in 1862 saw major flooding throughout the area{{snd}}the effect of which was exacerbated by the extent of the reclaimed lands. The first [[Dredging#Bucket|bucket dredge]] in Western Australia was the {{ship||Black Swan|dredge|2}}, used between 1872 and 1911 for dredging channels in the river, as well as reclamation.

{{gallery
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|File:Swan River 1918.jpg
|Swan River in 1918, showing the then as-yet largely undeveloped Mill Point area

|File:Light painting gnangarra-2.jpg
|[[Light painting]] on the banks of the Swan River in January 2012
}}

===Notable features===
A number of features of the river, particularly around the city, have reshaped its profile since European settlement in 1829:
[[File:Perth Water c.1909.png|thumb|right|1909 map showing Heirisson Islands and alignment of the Burswood Island canal]]
*[[Claise Brook]] – named ''Clause's Brook'' (after [[Frederick Clause]]) on early maps. This was a fresh water creek which emptied the network of natural lakes north of the city. Before an effective sewerage system was built, it became an open sewer which dumped waste directly into the river for many years during the 1800s and early 1900s. The area surrounding has been mainly industrial for most of the period of European settlement and it has a long history of neglect. Since the late 1980s, the East Perth redevelopment has dramatically tidied up the area and works include a landscaped inlet off the river large enough for boats. The area is now largely residential and the ''brook'' exists in name only with the lakes having been either removed or managed by artificial drainage systems.
*Point Fraser – early maps showed this as a major promontory on the northern side of the river west of the Causeway. It disappeared between 1921 and 1935 when land fill was added on both sides, straightening the irregular foreshore and forming the rectangular 'The Esplanade'.
*The Esplanade – the northern riverbank originally ran close to the base of the escarpment generally a single block width south of St Georges Terrace. Houses built on the southern side of St Georges Terrace included market gardens which ran to the waters edge.
*Heirisson Islands – a series of mudflats that were slightly more upstream from today's single artificial island which has deep channels on each side.
*Burswood – early in the settlement the Perth flats restricted the passage of all but flat bottom boats travelling between Perth and Guildford. It was decided that a [[Burswood Canal|canal]] be built to bypass these creating Burswood Island. In 1831 it took seven men 107 days to do the work. Once completed, it measured about {{convert|280|m}} in length by an average top width of nearly {{convert|9|m}} which tapered to {{convert|4|m}} at the bottom; the depth varied between nearly {{convert|1|and|6|m}}. Further improvements were made in 1834. The area on the south side of the river upstream from the causeway was filled throughout the 1900s, reclaiming an area five times the area of the Mitchell Interchange and Narrows Bridge works.
*Point Belches – later known as Mill Point, South Perth. Originally existed as a sandy promontory surrounding a deep semi-circular bay. This was later named Millers Pool and was eventually filled in and widened to become the present-day South Perth peninsula to which the Narrows Bridge and Kwinana Freeway adjoin.
*Point Lewis (also known as ''One-tree Point'' after a solitary tree that stood on the site for many years){{snd}}the northern side of the Narrows Bridge site, and now beneath the interchange.
*Mounts Bay – a modest reclamation was done between 1921 and 1935. In the 1950s works involving the Narrows Bridge started and in 1957 the bay was dramatically reduced in size with works related to the Mitchell Interchange and the northern approaches to the Narrows. An elderly [[Bessie Rischbieth]] famously protested against the project by standing in the shallows in front of the bulldozers for a whole day in 1957. She succeeded in halting progress{{snd}}for that one day.
*Bazaar Terrace/Bazaar Street – in the early days of the settlement this waterfront road between William Street and Mill Street was an important commercial focus with port facilities including several jetties adjoining. It is now approximately where Mounts Bay Road is today and set well back from the foreshore. It had a prominent limestone wall and promenade built using material quarried from Mount Eliza.
*River mouth at Fremantle – the harbour was built in the 1890s and the limestone reef blocking the river was removed at the same time, after 70 years of demands. The dredging of the area to build the harbour effectively changed the river dynamics from a winter flushing flow to a tidal flushing estuary. It was also at this time that the Helena River was dammed as part of [[C. Y. O'Connor]]'s ambitious and successful plan to provide water to the [[Kalgoorlie, Western Australia|Kalgoorlie]] Goldfields.

===Environmental issues===
The river has been used for the disposal of all kinds of waste. Even well into the 1970s, various local councils had rubbish tips on the mud flats along the edge of the river. Heavy industry also contributed its share of waste into the river from wool scouring plants in Fremantle to fertiliser and foundries sited in the Bayswater{{snd}}Bassendean area. Remedial sites works are still ongoing{{as of? |date=March 2025}} in these areas to remove the toxins left to leach into the river.

During the summer months there are problems with [[algal bloom]]s killing fish, caused by nutrient run-off from farming activities as well as the use of fertilisers in the catchment areas. The occasional accidental spillage of sewage and chemicals has also caused sections of the river to be closed to human access. The river has survived all this and is in relatively good condition considering on-going threats to its ecology.

In 2010 the Government of Western Australian imposed restrictions on phosphorus levels in fertilisers due to concerns about the health of the Swan and Canning river systems.<ref>{{cite news |url=http://www.theaustralian.com.au/business/wa-goes-it-alone-over-phosphorus/news-story/a8713bfe016446d97f17466235f35c22?nk=731cdf16ad1df64dadeb5468e95092e4-1507543299 |title=WA goes it alone over phosphorus |date=30 April 2010}}</ref>
{{Panorama
|image=File:MatildaBay gobeirne.jpg
|height=140
|caption=Matilda Bay on the Swan River, with [[Mount Eliza, Western Australia|Mount Eliza]] and the Perth skyline in the background
}}

===Flood events===
{{Bar chart
|title=Return period of flood events
|table_width=20
|float=right
|bar_width=35
|data_max=100
|label_type=Year<ref>{{cite web |url=http://www.ga.gov.au/image_cache/GA6527.pdf |website=Public Works Department |year=1986 |title=Avon River Flood Study: Revision A, prepared by Binnie and Partners Pty Ltd, Perth |access-date=15 January 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110317053858/http://www.ga.gov.au/image_cache/GA6527.pdf |archive-date=17 March 2011 }}</ref>
|data_type=Return period (years)
|label1=1862 |data1=60
|label2=1872 |data2=100
|label3=1910 |data3=20
|label4=1917 |data4=20
|label5=1926 |data5=30
|label6=1930 |data6=15
|label7=1945 |data7=20
|label8=1946 |data8=10
|label9=1955 |data9=20
|label10=1958 |data10=20
|label11=1963 |data11=15
|label12=1964 |data12=10
|label13=1983 |data13=10
}}
Data collection of flood events in the estuary has been performed since European arrival in 1829. In July 1830, barely a year after the establishment of the colony, the river rose {{convert|6|m}} above its normal level.<ref name="miro05" />{{rp|p=102}} New settlers were still arriving in steady numbers and few permanent buildings had been constructed, with most living in tents and other temporary accommodation. These included caves along the river's edge and many found their belongings washed away and livestock drowned.<ref>{{cite wikisource |wslink=History of West Australia |editor-first=Warren Bert |editor-last=Kimberly |editor-link=Warren Burt Kimberly |publication-date=1897 |page=55 |publication-place=Melbourne |publisher=F. W. Niven }}</ref> Other abnormal flooding events occurred in the winters of 1847 and 1860, while the most recent flooding occurred in 2017. Later events have since been assessed for their [[return period]].<ref name="miro05" />{{rp|p=102}}

The largest recorded flood event was in July 1872 which had a calculated return period of [[100-year flood|100 years]].<ref name="miro05" />{{rp|p=102}} At the Helena River, the 1872 flood level was {{convert|2|ft|3|in|mm|order=flip}} higher than the 1862 event with a return period of 60 years. An account in ''[[The West Australian#History|The Perth Gazette and Western Australian Journal]]'' on 26 July 1872 reported<ref>{{cite news |url=http://nla.gov.au/nla.news-article3752641 |title=Country News |work=[[The West Australian#History|The Perth Gazette and Western Australian Journal]] |date=26 July 1872 |access-date=13 September 2009}}</ref>
{{blockquote |text=In and about Perth, the water owing to the force of the incoming seas at the mouth of the river presented a scene of a great lake, all the jetties were submerged, the high roads to Fremantle covered, and passage traffic rendered impossible quantities of sandalwood lying along the banks of river were washed away, and the inhabitants of the suburban villas on the slopes of Mount Eliza obliged to scramble up the hill sides to get into Perth.}}

The flood of July 1926, with a return period of 30 years,<ref name="miro05" />{{rp|p=102}} resulted in the washing away of the Yagan Bridge and a section of the Fremantle Railway Bridge.<ref>{{cite book |last=Brearley |first=Anne |date=2005 |title=Ernest Hodgkin's Swanland: Estuaries and Coastal Lagoons of South-western Australia |publisher=[[University of Western Australia Press|UWAP]] for the Ernest Hodgkin Trust for Estuary Education and Research and [[National Trust of Australia (WA)]] |isbn=978-1-920694-38-8 |page=86 |quote=Re the 1926 flood: ''floodwaters spread over 5 kilometres at Guildford, and covered large areas of Perth Esplanade, and South Perth... and 12,729 million litres cascaded over Mundaring Weir'' |location=Crawley }}</ref> The Fremantle bridge partially collapsed on 22 July 1926, five minutes after a train containing schoolchildren had passed over.<ref>{{cite news |url=http://nla.gov.au/nla.news-article46532437 |title=THE WESTERN AUSTRALIAN FLOODS. |newspaper=[[The Advertiser (Adelaide)|The Advertiser]] |location=Adelaide |date=23 July 1926 |access-date=21 February 2012 |page=17 |publisher=National Library of Australia}}</ref> No one was injured in the collapse; however, it created major disruption to commerce for several months. Repairs were completed and the bridge reopened on 12 October 1926.<ref>{{cite news |url=http://nla.gov.au/nla.news-article31954082 |title=FREMANTLE RAILWAY BRIDGE. |newspaper=[[The West Australian]] |location=Perth |date=12 October 1926 |access-date=21 February 2012 |page=7 |publisher=National Library of Australia}}</ref>
{{gallery
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|title=1926 floods

|Mill Point, South Perth, 1926 floods.jpg
|Mill Point, South Perth, during the 1926 floods

|North Fremantle Railway Bridge collapse, 1926.jpg
|North Fremantle Railway Bridge collapse in 1926
}}
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