Murchison River (Western Australia)

The Murchison River basin covers an area of about {{convert|82000|km2|sqmi|0}} in the Mid West region of Western Australia. It extends about {{convert|550|km|mi|abbr=on}} inland from the Indian Ocean, onto the Yilgarn craton east of Meekatharra and north of Sandstone.{{cite web|title=Murchison-Gascoyne Region|archive-url=https://web.archive.org/web/20170413235745/https://www.water.wa.gov.au/__data/assets/pdf_file/0017/5183/43415_Part6.pdf|archive-date=13 April 2017 |url=https://www.water.wa.gov.au/__data/assets/pdf_file/0017/5183/43415_Part6.pdf|website=Water Resources|publisher=Department of Water, Government of Western Australia|access-date=13 April 2017|page=69|format=pdf}} Rain generally falls in the upper basin during summer cyclones, so for much of the year the Murchison River does not flow, leaving a dry sandy river bed and intermittent permanent pools.

The eastern reaches of the basin contain large chains of salt lakes, which flow only following rainfall. The drainage lines from these lakes merge to form the Murchison River about {{convert|90|km|mi|abbr=on}} north-northeast of Meekatharra. The river flows west, southwest, and west to the Indian Ocean.

Within the basin are the towns of Kalbarri and Meekatharra; the hamlets of Ajana, Binnu, Barrel Well and Murchison; and the mining ghost towns of Galena, Geraldine, Abbotts, Chesterfield, Peak Hill, Yaloginda, Reedy, Nannine, Quinns, Burnakura and Gabanintha.

The Murchison River rises on the southern slopes of the Robinson Ranges, about {{convert|75|km|mi|abbr=on}} north of Meekatharra in central Western Australia. From there it flows in a westerly direction for about {{convert|130|km|mi|abbr=on}} to its junction with its largest tributary, the Yalgar River, then west for another {{convert|100|km|mi|abbr=on}} before turning south-southwest for {{convert|120|km|mi|abbr=on}}, at which point it is joined by the Roderick River, about {{convert|30|km|mi|abbr=on}} east of Murchison Settlement. Another {{convert|70|km|mi|abbr=on}} to the south-southwest it joins another important tributary, the Sanford River. Over the next {{convert|100|km|mi|abbr=on}} it makes a number of sharp turns, taking it about {{convert|70|km|mi|abbr=on}} to the west. It then flows to the southwest, flowing under the North West Coastal Highway at the Galena Bridge. Entering the Kalbarri National Park, it flows first to the northwest and then to the north, flowing through the Murchison Gorge, and passing through a number of tight bends known as the Z Bend and The Loop respectively. It eventually turns to the southwest, passing through one more dogleg before discharging into the Indian Ocean at Kalbarri, the only town on the river.{{cite web | url = http://portal.environment.wa.gov.au/pls/portal/docs/page/doe_admin/guideline_repository/sowr_murchisongascoyne.pdf | title = Murchison-Gascoyne region | access-date = 3 July 2012 | format = pdf | publisher = Government of Western Australia Department of Environment and Conservation }}{{Dead link|date=April 2020 |bot=InternetArchiveBot |fix-attempted=yes }}

Murchison Gorge is a deep gorge in near pristine condition. It is popular with tourists, and there are a number of tourist lookouts. It is also of geological interest, as it exposes a section through the Tumblagooda Sandstone, a geological sequence rich in Ordovician trace fossils. The maximum age for initiating major down-cutting of the Murchison Gorge, in response to regional Quaternary tectonism, is Late Eocene (33.9–38 million years ago).{{cite book |last1=Hocking |first1=Roger M. |last2=Mory |first2=Arthur J. |title=Geology of the Kalbarri area — a field guide |date=20 December 2006 |publisher=Western Australia Geological Survey |location=Perth, WA |isbn=978 1 74168 075 1 |page=6 |url=https://geodocs.dmirs.wa.gov.au/Web/documentlist/3/Combined/N06XL |access-date=3 November 2020}}

The final {{convert|18|km|mi|0}} of the Murchison River, from the Murchison House ford to the mouth, are estuarine, and consist of a sequence of long sandbars and shallow pools mostly less than a metre deep. The estuary is permanently open to the sea, so is constantly affected by tides and the inflow of saline sea water. When river flow is low, the estuary accumulates sediment from the ocean, narrowing the river channel; this sediment is evacuated to the ocean during periods of high flow, but high flow also brings sediment into the estuary from upriver. Because of the high sediment load, and continual stirring by wind and river flow, the water is turbid.{{cite book | first = Anne | last = Brearley | year = 2005 | title = Ernest Hodgkin's Swanland: Estuaries and coastal lagoons of Southwestern Australia | publisher = University of Western Australia Press | isbn = 1-920694-38-2 | pages = 262–271}}

The mouth of the estuary is a small delta, closed by a sandbar except for a narrow channel. Although this channel is permanently open, it is usually very narrow and shallow, and so is now dredged every year to allow passage by western rock lobster fishing boats.

The Murchison River was named by the explorer George Grey, whose boats were wrecked at its mouth on 1{{nbsp}}April 1839, during his second disastrous exploratory expedition; the name honours Grey's patron, the Scottish geologist Sir Roderick Murchison.{{cite book | last1 = Grey | first1 = George | title = Journals of two expeditions of discovery in North-West and Western Australia, during the years 1837, 38, and 39, describing many newly discovered, important, and fertile districts, with observations on the moral and physical condition of the aboriginal inhabitants, etc. etc. | volume = 2 | publisher = T. and W. Boone | year = 1841 | location = London | page = 3 | url = http://www.gutenberg.org/files/16145/16145-h/16145-h.htm | access-date = 17 March 2012}} Murchison's advocacy had been essential in securing official support for Grey's Western Australian expeditions.{{cite book | last1 = Stafford | first1 = Robert A. | title = Scientist of Empire: Sir Roderick Murchison, scientific exploration and Victorian imperialism | publisher = Cambridge University Press | year = 1989 | location = Cambridge | page = 41 | isbn = 0 521 33537 X}}

Murchison House Station, one of the oldest stations in Western Australia, was established by Charles Von Bibra on the banks of the river toward the western end in 1858.{{cite web|url=http://www.murchisonhousestation.com.au/|title=Murchsin House Station|access-date=22 June 2019|publisher=Murchison House Station}}

The estuary and river mouth was used as a holiday destination by families from the Galena mines in the 1920s and 1930s, and a military holiday camp was built there during World War{{nbsp}}II.

In 1951 the town of Kalbarri was gazetted at the river mouth, and by the end of the 1990s the population was about 2,000. In 1963 the Kalbarri National Park was gazetted, formally protecting the lower reaches of the river, including the gorge.

The Galena Bridge, carrying North West Coastal Highway over the river at Galena, was opened by the Main Roads Department in December 1983.Edmonds, Leigh (1997), The vital link : a history of Main Roads Western Australia 1926-1996 Nedlands, W.A. : University of Western Australia Press. {{ISBN|1-876268-06-9}}. page 452

Flooding occurred in 1866 resulting in the Geraldine Mine being drowned;{{cite news |url=http://nla.gov.au/nla.news-article41027751 |title=Western Australia. |newspaper=South Australian Register |location=Adelaide |date=13 April 1866 |access-date=24 June 2012 |page=3 |publisher=National Library of Australia}} more flooding occurred in 1882.{{cite news |url=http://nla.gov.au/nla.news-article47104217 |title=Western Australia |newspaper=South Australian Register |location=Adelaide |date=28 March 1882 |access-date=24 June 2012 |page=5 |publisher=National Library of Australia}}

The southern branch flooded out to a distance of {{convert|6|mi|km|0}} from the river bank in 1884 and the main homestead at Moorarie Station was washed away with about 3,000 ewes and lambs.{{cite news |url=http://nla.gov.au/nla.news-article2991250 |title=Occasional Notes |newspaper=The West Australian |location=Perth |date=13 May 1884 |access-date=30 September 2013 |page=3 |publisher=National Library of Australia}}

The river was once again flooded in 1900 following heavy rains with the river estimated to be running {{convert|8|mi|km|0}} wide, road to Cue and Peak Hill were submerged under {{convert|10|ft|m|0}} of water. Roads were cut for up to a fortnight resulting in food shortages in many isolated towns.{{cite news |url=http://nla.gov.au/nla.news-article67186623 |title=The Murchison Downpour, subsidence of the flood|newspaper=The Inquirer & Commercial News |location=Perth |date=20 April 1900 |access-date=24 June 2012 |page=9 |publisher=National Library of Australia}} Ernest Lee Steere of Belele Station reported that over {{convert|5|in}} of rain fell in less than a fortnight. Further downstream the river was reported to be running {{convert|15|mi|km|0}} wide and at depths of up to {{convert|70|ft|m|0}}; despite the damage, pastoralists were jubilant at how quickly the grasses were growing.{{cite news |url=http://nla.gov.au/nla.news-article33177818 |title=Pastoralists jubilant |newspaper=Western Mail |location=Perth |date=5 May 1900 |access-date=24 June 2012 |page=23 |publisher=National Library of Australia}}

Heavy flooding occurred along the course of the river in March 1926 following heavy rains upstream.{{cite news |url=http://nla.gov.au/nla.news-article58321343 |title=Flood waters in the Murchison. |newspaper=Sunday Times |location=Perth |date=12 June 1927 |access-date=24 June 2012 |page=24 |publisher=National Library of Australia}} 15 to 20 men were stranded at the Three Sisters Mine on the north side of the river, at Galena, and were rescued by dinghy.{{cite news |url=http://nla.gov.au/nla.news-article21023057 |title=Miners marooned. |newspaper=The Brisbane Courier |location=Queensland. |date=26 March 1926 |access-date=24 June 2012 |page=7 |publisher=National Library of Australia}}

Flooding again occurred in 1939{{cite news |url=http://nla.gov.au/nla.news-article70405103 |title=Goldfields Flood |newspaper=Albany Advertiser |location=Western Australia |date=19 January 1939 |access-date=24 June 2012 |page=1 |publisher=National Library of Australia}} and 1942,{{cite news |title=Growers' Big Loss|url=https://trove.nla.gov.au/newspaper/article/75132110 |access-date=17 May 2024 |work=Nortern Times |date=14 February 1942 |location=Carnarvon, WA |page=2}} and once more following another significant rain event in February 1945 that resulted in flooding and the old Galena Bridge being swept away, effectively stranding the citizens of Carnarvon. A ferry service was established using a fishing boat.{{cite news |url=http://nla.gov.au/nla.news-article44999058 |title=Murchison Flood |newspaper=The West Australian |location=Perth |date=26 February 1945 |access-date=24 June 2012 |page=4 2nd Edition |publisher=National Library of Australia}} Bananas were the main item that urgently needed to be sent across for transport to market.{{cite news |title=Bananas Swim RIver |url=https://trove.nla.gov.au/newspaper/article/78572937 |access-date=17 May 2024 |work=The Daily News |date=20 February 1942 |location=Perth, WA |page=8}}

Following Cyclone Emma in 2006, much of the catchment area received {{convert|100|mm|in|0}} of rainfall. The river swelled, reaching a width of over {{convert|20|km|mi|0}} in places, and Kalbarri had to be sandbagged to protect it from floodwaters.{{cite news |url=http://www.abc.net.au/news/2006-03-14/wa-rivermouth-closed-after-waters-rise/818142 |title=WA rivermouth closed after waters rise|date=14 March 2006|access-date=17 February 2013|publisher=Australian Broadcasting Corporation}}

• Bilyuin Pool
• Pencell Pool
• Wooleen Station

{{Reflist|2}}

• Curry, P.J. et al. (1994) An inventory and condition survey of the Murchison River catchment and surrounds, Western Australia. Department of Agriculture, Western Australia: Technical Bulletin Number 84. {{ISBN|0-7309-5998-8}}
• Western Australia. Dept. of Land Administration. Cartographic Services Branch.(1991) Land systems of the Murchison River catchment and surrounds : map series to accompany W.A. Department of Agriculture technical bulletin no. 84 Map Data: Scale 1:250,000 (E 115° 10′--E 118° 45′/S 25°—S 28° 10′).Notes: Land systems of the Murchison River catchment and surrounds by K.A. Leighton ... [et al.]. Date of survey: 1986-1988. Location maps:Belele, Byro, Cue, Glenburgh, Murgoo, Robinson Range.

{{Coord|27|42|27|S|114|9|36|E|type:river_region:AU-WA|display=title}}

{{Rivers of Western Australia}}

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Category:Rivers of the Mid West region

Category:Kalbarri, Western Australia