| Swan River Derbarl Yerrigan (Nyungar) | |
|---|---|
.jpg) Swan River passing through the centre of Perth | |
 Map of the area around Perth, showing the location of the Swan River | |
| Location | |
| Country | Australia |
| State | Western Australia |
| City | Perth;Fremantle |
| Physical characteristics | |
| Source confluence | Avon River withWooroloo Brook |
| • location | below Mount Mambup |
| • coordinates | 31°44′34″S116°4′3″E / 31.74278°S 116.06750°E /-31.74278; 116.06750 |
| • elevation | 53 m (174 ft) |
| Mouth | Indian Ocean |
• location | Fremantle |
• coordinates | 32°4′25″S115°42′52″E / 32.07361°S 115.71444°E /-32.07361; 115.71444 |
• elevation | 0 m (0 ft) |
| Length | 72 km (45 mi) |
| Basin size | 121,000 km2 (47,000 sq mi) |
| Basin features | |
| Tributaries | |
| • left | Susannah Brook,Jane Brook |
| • right | Ellen Brook,Helena River,Bennett Brook,Canning River |
| [1]: 3 [disputed (for: chapter starts at page 91) –discuss] | |
TheSwan River (Nyungar:Derbarl Yerrigan[2][3]) is a major river in thesouthwest of Western Australia. The river runs through the metropolitan area ofPerth, Western Australia's capital and largest city.
The Swan River estuary flows through the city ofPerth. Its lower reaches are relatively wide and deep, with few constrictions, while the upper reaches are usually quite narrow and shallow.
The Swan River drains the Avon andcoastal plain catchments, which have a total area of about 121,000 square kilometres (47,000 sq mi). It has three major tributaries, theAvon River,Canning River andHelena River. The latter two havedams (Canning Dam andMundaring Weir) which provide a sizeable part of the potable water requirements for Perth and the surrounding regions. The Avon River contributes the majority of the freshwater flow. The climate of the catchment is Mediterranean, with mild wet winters, hot dry summers, and the associated highly seasonal rainfall and flow regime.
The Avon rises nearYealering, 221 kilometres (137 mi) southeast of Perth: it meanders north-northwest toToodyay about 90 kilometres (56 mi) northeast of Perth, then turns southwest inWalyunga National Park – at the confluence of the Wooroloo Brook, it becomes the Swan River.
The Canning River rises fromNorth Bannister, 100 kilometres (62 mi) southeast of Perth and joins the Swan atApplecross, opening intoMelville Water. The river then narrows intoBlackwall Reach, a narrow and deep stretch leading the river throughFremantle Harbour to thesea.
The estuary is subject to a microtidal regime, with a maximum tidal amplitude of about 1 metre (3 ft 3 in), although water levels are also subject to barometric pressure fluctuations.
Before theTertiary, when the sea level was much lower than at present, the Swan River curved around to the north ofRottnest Island, and disgorged itself into the Indian Ocean slightly to the north and west of Rottnest. In doing so, it carved a gorge about the size of theGrand Canyon. Now known asPerth Canyon, this feature still exists as asubmarine canyon near the edge of thecontinental shelf.
The Swan River drains the Swan Coastal Plain, a total catchment area of over 100,000 square kilometres (39,000 sq mi) in area. The river is located in a Mediterranean climate, with hot dry summers and cool wet winters, although this balance appears to be changing due to climate change. The Swan is located on the edge of the Darling Scarp, flowing downhill across the coastal plain to its mouth at Fremantle.
The Swan begins as the Avon River, rising near Yealering in theDarling Range, approximately 175 kilometres (109 mi) from its mouth at Fremantle. The Avon flows north, passing through the towns ofBrookton,Beverley,York,Northam andToodyay. It is joined by tributaries including theDale River, theMortlock River and the Brockman River. The Avon becomes the Swan as Wooroloo Brook enters the river near Walyunga National Park.
More tributaries includingEllen Brook,Jane Brook, Henley Brook, Wandoo Creek,Bennett Brook, Blackadder Creek, Limestone Creek, Susannah Brook, and theHelena River enter the river between Wooroloo Brook andGuildford; however, most of these have either dried up or become seasonally flowing due to human impacts such as land clearing and development.
Between Perth and Guildford the river goes through several loops. Originally, areas including the Maylands Peninsula,Ascot andBurswood, throughClaise Brook and north of the city toHerdsman Lake were swampy wetlands. Most of the wetlands have since been reclaimed for land development.Heirisson Island, upon whichThe Causeway passes over, was once a collection of small islets known as the Heirisson Islands.[4][5][6]
Perth Water, between the city and South Perth, is separated from the main estuary by the Narrows, over which theNarrows Bridge was built in 1959. The river then opens up into the large expanse of the river known as Melville Water. TheCanning River enters the river at Canning Bridge in Applecross from its source 50 kilometres (31 mi) south-east ofArmadale. The river is at its widest here, measuring more than 4 kilometres (2.5 mi) from north to south.Point Walter has a protruding spit that extends up to 800 metres (2,600 ft) into the river, forcing river traffic to detour around it.
The river narrows between Chidley Point and Blackwall Reach, curving around Point Roe and Preston Point before narrowing into the harbour.Stirling Bridge and theFremantle Traffic Bridge cross the river north of the rivermouth. The Swan River empties into the Indian Ocean at Fremantle Harbour.
Plant and animal life found in or near the Swan-Canning Estuary include:
The river was namedSwarte Swaene-Revier[10] by Dutch explorer,Willem de Vlamingh in 1697, after the famousblack swans of the area. Vlamingh sailed with a small party up the river to aroundHeirisson Island.[11] A French expedition underNicholas Baudin also sailed up the river in 1801.[12]: 138–145
Governor Stirling's intention was that the nameSwan River refer only to the watercourse upstream of the Heirisson Islands.[10] All of the rest, including Perth Water, he considered estuarine and which he referred to asMelville 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."[This quote needs a citation]
Almost immediately after the Town of Perth was established, a systematic effort was underway to reshape the river. This was done for many reasons:
Perth streets were often sandy bogs which caused GovernorJames Stirling in 1837 to report to the Secretary of State for Colonies:[This quote needs a citation]
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 – the effect of which was exacerbated by the extent of the reclaimed lands. The firstbucket dredge in Western Australia was theBlack Swan, used between 1872 and 1911 for dredging channels in the river, as well as reclamation.
A number of features of the river, particularly around the city, have reshaped its profile since European settlement in 1829:
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 – Bassendean area. Remedial sites works are still ongoing[as of?] in these areas to remove the toxins left to leach into the river.
During the summer months there are problems withalgal blooms 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.[13]
| Year[14] | Return period (years) |
|---|---|
| 1862 | 60 |
| 1872 | 100 |
| 1910 | 20 |
| 1917 | 20 |
| 1926 | 30 |
| 1930 | 15 |
| 1945 | 20 |
| 1946 | 10 |
| 1955 | 20 |
| 1958 | 20 |
| 1963 | 15 |
| 1964 | 10 |
| 1983 | 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 6 metres (20 ft) above its normal level.[1]: 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.[15] 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 theirreturn period.[1]: 102
The largest recorded flood event was in July 1872 which had a calculated return period of100 years.[1]: 102 At the Helena River, the 1872 flood level was 690 millimetres (2 ft 3 in) higher than the 1862 event with a return period of 60 years. An account inThe Perth Gazette and Western Australian Journal on 26 July 1872 reported[16]
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,[1]: 102 resulted in the washing away of the Yagan Bridge and a section of the Fremantle Railway Bridge.[17] The Fremantle bridge partially collapsed on 22 July 1926, five minutes after a train containing schoolchildren had passed over.[18] 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.[19]
TheSwan River Trust was a state government body, within the ambit of theDepartment of Environment and Conservation (Western Australia) – that was constituted in 1989 after legislation passed the previous year, that reports to the Minister for the Environment. It brings together eight representatives from the community, State and local government authorities with an interest in the Swan and Canning rivers to form a single body responsible for planning, protecting and managing Perth's river system.[20][21]
The functions of the trust have been absorbed by the subsequent Western Australian Environmental protection authorities, the most recent change being in 2017, to theDepartment of Biodiversity, Conservation and Attractions.
In the earliest days of theSwan River Colony, the river was used as the main transport route between Perth and Fremantle. This continued until the establishment of the government rail system between Fremantle and Guildford via Perth.
There are currently 22 road and railway bridges crossing the Swan River. These are (from Fremantle, headingupstream):[b]
.jpg)
The earliest club was theWest Australian Rowing Club. TheSwan River Rowing Club started in 1887.[22] The Fremantle Rowing Club had started by the 1890s.[23]
There are currently fifteen yacht clubs along the Swan River, with most onMelville Water,Freshwater Bay andMatilda Bay.Royal Perth Yacht Club, onPelican Point inMatilda Bay, staged the unsuccessful1987 America's Cup defence, the first time in 132 years it had been held outside of the United States.Royal Perth Yacht Club and theRoyal Freshwater Bay Yacht Club are the only two clubs to be granted aroyal charter. There are also many anchorages and marinas along the lower reaches nearFremantle.
The river is a significant part of Perth culture, with many water sports such as rowing, sailing, and swimming all occurring in its waters.
There have been somenorth of the river orsouth of the river distinctions in the Perth metropolitan region over time,[24][25] especially in the time up to the completion of the Causeway and Narrows bridges, due to the time and distances to cross the river.
The river was the site of theCity of Perth Skyworks, a fireworks show held each year onAustralia Day from 1985 until 2022, with spectators crowding the foreshore,Kings Park, and on boats on the river to watch the event.
TheNoongar people believe that the Darling Scarp represents the body of aWagyl (also spelt Waugal) – a snakelike being fromDreamtime that meandered over the land creating rivers, waterways and lakes. It is thought that the Wagyl created the Swan River.
{{cite book}}: CS1 maint: others (link){{citation}}: CS1 maint: numeric names: authors list (link)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
Media from CommonsRivers ofWestern Australia | |
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| Rivers of theGascoyne region | |
| Rivers of theGoldfields–Esperance region | |
| Rivers of theGreat Southern region | |
| Rivers of theKimberley region |
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| Rivers of theMid West region | |
| Rivers of thePeel andPerth regions | |
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