Swan River (Western Australia)

The Swan River () is a major river in the southwest of Western Australia. The river runs through the metropolitan area of Perth, Western Australia's capital and largest city.

Course of river

The Swan River estuary flows through the city of Perth. 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 and coastal plain catchments, which have a total area of about . It has three major tributaries, the Avon River, Canning River and Helena River. The latter two have dams (Canning Dam and Mundaring 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 near Yealering, southeast of Perth: it meanders north-northwest to Toodyay about northeast of Perth, then turns southwest in Walyunga National Parkat the confluence of the Wooroloo Brook, it becomes the Swan River.

The Canning River rises from North Bannister, southeast of Perth and joins the Swan at Applecross, opening into Melville Water. The river then narrows into Blackwall Reach, a narrow and deep stretch leading the river through Fremantle Harbour to the Indian Ocean.

The estuary is subject to a microtidal regime, with a maximum tidal amplitude of about , although water levels are also subject to barometric pressure fluctuations.

Naming and terminology

The Swan River and the Avon River are the same watercourse. By convention, the name "Swan" is used from the river mouth at Fremantle Harbour until the river reaches the Walyunga National Park, a distance of approximately . The name "Avon" is then used upstream of the confluence with the Wooroloo Brook. The naming convention has been described as a "historical anomaly". For that reason, the main branch of the river system is sometimes referred to as the Swan–Avon River.

Approximately of the Swan River is estuarine in nature with brackish water, with the effects of ocean tides extending inland as far as the confluence with Ellen Brook. The "true river" portion of the Swan historically culminated in a mudflat delta at what is now Heirisson Island. Technical sources regard the Swan–Avon and Canning as separate rivers flowing into a single body of water, the Swan–Canning Estuary, at Melville Water, rather than treating the Canning as a tributary of the Swan. This distinction was noted as early as 1827 by James Stirling.

Geology

Before the Tertiary, when the sea level was much lower than at present, the Swan River curved around to the north of Rottnest 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 the Grand Canyon. Now known as Perth Canyon, this feature still exists as a submarine canyon near the edge of the continental shelf.

Geography

thumb|right|Satellite imagery of the Swan River and surrounds

The Swan River drains the Swan Coastal Plain, a total catchment area of over 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.

Sources

The Swan begins as the Avon River, rising near Yealering in the Darling Range, approximately from its mouth at Fremantle. The Avon flows north, passing through the towns of Brookton, Beverley, York, Northam and Toodyay. It is joined by tributaries including the Dale River, the Mortlock River and the Brockman River. The Avon becomes the Swan as Wooroloo Brook enters the river near Walyunga National Park.

Tributaries

More tributaries including Ellen Brook, Jane Brook, Henley Brook, Wandoo Creek, Bennett Brook, Blackadder Creek, Limestone Creek, Susannah Brook, and the Helena River enter the river between Wooroloo Brook and Guildford; however, most of these have either dried up or become seasonally flowing due to human impacts such as land clearing and development.

Swan coastal plain

thumb|right|Swampy wetlands between Perth and Guildford have been reclaimed for land development; however, The Perth skyline can be seen in the far distance.

Between Perth and Guildford the river goes through several loops. Originally, areas including the Maylands Peninsula, Ascot and Burswood, through Claise Brook and north of the city to Herdsman Lake were swampy wetlands. Most of the wetlands have since been reclaimed for land development. Heirisson Island, upon which The Causeway passes over, was once a collection of small islets known as the Heirisson Islands.

Perth Water and Melville Water

Perth Water, between the city and South Perth, is separated from the main estuary by the Narrows, over which the Narrows Bridge was built in 1959. The river then opens up into the large expanse of the river known as Melville Water. The Canning River enters the river at Canning Bridge in Applecross from its source south-east of Armadale. The river is at its widest here, measuring more than from north to south. Point Walter has a protruding spit that extends up to into the river, forcing river traffic to detour around it.

Narrowing and Fremantle

thumb|Sunset over the river mouth in Fremantle, with a bottlenose dolphin swimming across the middle of the screen

The river narrows between Chidley Point and Blackwall Reach, curving around Point Roe and Preston Point before narrowing into the harbour. Stirling Bridge and the Fremantle Traffic Bridge cross the river north of the rivermouth. The Swan River empties into the Indian Ocean at Fremantle Harbour.

Notable features

Fremantle Harbour
Point Brown
Rous Head
Arthur Head
Victoria Quay
Point Direction
Preston Point
Rocky Bay
Point Roe
Chidley Point
Blackwall Reach
Butler's Hump
Point Walter
Mosman Bay
Keanes Point
Freshwater Bay
Point Resolution
Melville Water
Lucky Bay
Point Waylen
Alfred Cove
Point Dundas
Waylen Bay
Point Heathcote
Quarry Point
Mounts Bay
Point Lewis
Mill Point
Point Belches
Elizabeth Quay
Pelican Point
Matilda Bay
The Narrows
Perth Water
Point Fraser
Heirisson Island
Claise Brook
Maylands Peninsula
Ron Courtney Island
Swan Valley
Kuljak Island

Flora and fauna

Plant and animal life found in or near the Swan-Canning Estuary include:

Over 130 species of fish including bull sharks
Molluscs including Mytilidae, Galeommatidae
Birds including the eponymous black swan, silver gull, cormorants (locally referred to as "shags"), twenty-eight parrots, rainbow lorikeet, kingfisher, red-tailed black cockatoo, Australian pelican, Australian magpie, heron and ducks

History

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]]

thumb|right|The first detailed map of the Swan River, drawn by François-Antoine Boniface Heirisson in 1801

The river was named by the Dutch explorer Willem de Vlamingh in 1697, after the famous black swans of the area. Vlamingh sailed with a small party up the river to around Heirisson Island. A French expedition under Nicholas Baudin also sailed up the river in 1801.

Flood events

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 above its normal level. 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.

The flood of July 1926, with a return period of 30 years, The Fremantle bridge partially collapsed on 22 July 1926, five minutes after a train containing schoolchildren had passed over. 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.

Governance

The Swan River Trust was a state government body, within the ambit of the Department 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.

The functions of the trust have been absorbed by the subsequent Western Australian Environmental protection authorities, the most recent change being in 2017, to the Department of Biodiversity, Conservation and Attractions.

Human uses

Transport

In the earliest days of the Swan 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.

Bridges

thumb|[[Matagarup Bridge]]

There are currently 22 road and railway bridges crossing the Swan River. These are (from Fremantle, heading upstream):

Fremantle Railway Bridge, North Fremantle to Fremantle (Eastern railway line)
Fremantle Traffic Bridge, North Fremantle to Fremantle
Stirling Bridge (Stirling Highway), North Fremantle to East Fremantle
Narrows Bridge, South Perth to Perth (Kwinana Freeway and Mandurah railway line; 2001)northbound
Narrows Bridge, Perth to South Perth (Mandurah railway line)
Narrows Bridge, Perth to South Perth (Kwinana Freeway; 1959)southbound
Boorloo Bridge comprising two bridges: between East Perth and Heirisson Island (north-west), and between Heirisson Island and Victoria Park (south-east)
The Causeway bridges between East Perth and Heirisson Island (north-west), and between Heirisson Island and Victoria Park (south-east)
Matagarup Bridge, East Perth to Perth Stadium, Burswood (pedestrian bridge)
Goongoongup Bridge, East Perth to Burswood (Armadale line)
Windan Bridge, East Perth to Burswood, (Graham Farmer Freeway)
Garratt Road Bridge, Bayswater to Ascotnorthbound
Garratt Road Bridge, Ascot to Bayswater (Garratt Road and Grandstand Road)southbound
Mooro-Beeloo Bridge, Bayswater to Ascot (Tonkin Highway)
Guildford Road Bridge, Bassendean to Guildford (Guildford Road and Bridge Street)
Guildford Railway Bridge, Bassendean to Guildford (Eastern railway line)
Barkers Bridge, Guildford to Caversham (Meadow Street and West Swan Road)
Whiteman Bridge, Caversham to Middle Swan (Reid Highway and Roe Highway)
Maali Bridge, Henley Brook to Herne Hill (pedestrian bridge; formerly called Barrett Street Bridge)
Yagan Bridge, Belhus to Upper Swan (Great Northern Highway; formerly called Upper Swan Bridge)
Upper Swan railway bridge, Upper Swan (unnamed)
Bells Rapids bridge, Upper Swan to Brigadoon (unnamed)

Rowing clubs

The earliest club was the West Australian Rowing Club. The Swan River Rowing Club started in 1887. The Fremantle Rowing Club had started by the 1890s.

Yacht clubs

There are currently fifteen yacht clubs along the Swan River, with most on Melville Water, Freshwater Bay and Matilda Bay. Royal Perth Yacht Club, on Pelican Point in Matilda Bay, staged the unsuccessful 1987 America's Cup defence, the first time in 132 years it had been held outside of the United States. Royal Perth Yacht Club and the Royal Freshwater Bay Yacht Club are the only two clubs to be granted a royal charter. There are also many anchorages and marinas along the lower reaches near Fremantle.

Cultural significance

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 some north of the river or south of the river distinctions in the Perth metropolitan region over time, 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 the City of Perth Skyworks, a fireworks show held each year on Australia Day from 1985 until 2022, with spectators crowding the foreshore, Kings Park, and on boats on the river to watch the event.

Aboriginal

The Noongar people believe that the Darling Scarp represents the body of a Wagyl (also spelt Waugal)a snakelike being from Dreamtime that meandered over the land creating rivers, waterways and lakes. It is thought that the Wagyl created the Swan River.

Notes

References

External links

Swan River Trust
Bridging to South Perth by Lloyd Margetts A copy of his speech given to the South Perth Historical Society.
Historical map of the Swan River
Swan River Electronic Navigation Chart
University of Western Australia – Center for Water Research