|⁃ location||near Pardelup|
|⁃ elevation||160 metres (525 ft)|
|Length||60 kilometres (37 mi)|
|Basin size||800 square kilometres (309 sq mi)|
|⁃ average||30,584 ML/a (1.0801×109 cu ft/a)|
The Denmark River is located in the Great Southern region of Western Australia. The river rises near Pardelup and meanders in a southerly direction until it flows through Denmark into Wilson Inlet (along with the Hay River). The traditional owners of the area are the Noongar people, who know the river as Kwoorabup, meaning the place of the Western brush wallaby (place we return to).
The river was named in December 1829 by naval ship's surgeon Thomas Braidwood Wilson after his mentor, naval surgeon Alexander Denmark, Physician of the Fleet, Resident Physician at the Royal Hospital Haslar, and past-Physician to the Mediterranean Fleet. Wilson discovered the river while exploring the area in company of the native Mokare, John Kent (officer in charge of the Commissariat at King George Sound), two convicts and Private William Gough of the 39th Regiment, while his ship the Governor Phillips was being repaired at King George Sound.
The river flows through Denmark Pipehead Dam. The two tributaries of the river are Scotsdale Brook and Cleerillup Creek.
The southern portion of the river was protected under a management plan of the Denmark Shire Council in 2011. The ceremonial site has been used by Noongar people for over 10,000 years as a place of dance, song, marriage preparation, initiation and food gathering. The area has high cultural significance due largely to its totemic significance and creation by the Wagyl in the Dreaming.
Historically the Denmark River's water quality declined as a result of land clearing in the catchment area since European settlement. It is estimated that 40% of the river's upper catchment area was cleared and as a result salinity levels increased from 40 mg/L in the 1940s to a peak of 1520 mg/L in 1987 at the Mt Lindesay gauging station.
In 2004 it was announced that salinity levels in the river were decreasing, believed to be the first major river in Australia that had shown a reversal in salinity trends, and that it is possible that the river could provide drinking quality water in the future.
By 2012 average annual salinity levels had dropped to 470 mg/L, below World Health Organization guidelines for drinking water for the first time in nearly 40 years. The improved water quality means Denmark Dam has been returned as a drinking water source and back-up water supply for Denmark.
- Western Australian Land Information Authority. "History of river names". Archived from the original on 16 February 2015. Retrieved 4 August 2008.
- "Bonzle Digital Atlas - Map of Denmark River, WA". 2008. Retrieved 23 November 2008.
- "South Coast Rivercare - Denmark River". 2007. Retrieved 5 November 2010.
- "Dual Naming Project" (PDF). Shire of Denmark. Retrieved 3 June 2017.
- "Plants of the Denmark walk trails:Traditional Noongar Names and Uses". Green Skills Inc. Retrieved 28 May 2017.
- Wilson, Thomas Braidwood (1835). Narrative of a Voyage Round the World. London: Sherwood Gilbert & Piper. p. 261.
- Wilson, Thomas Braidwood (1833), "Extract of a letter received from Dr J.B. Wilson, R.N., dated King George's Sound, 15th December, 1829", in Cross, Joseph (ed.), Journals of Several Expeditions Made in Western Australia During the Years 1829, 1830, 1831 and 1832: Under the Sanction of the Governor, Sir James Stirling, London: J. Cross, pp. 14–26
- Pearn, John (2001). A Doctor In The Garden: Nomen Medici In Botanicis : Australian Flora And The World Of Medicine. Brisbane, Qld: Amphion Press. p. 136. ISBN 978-1864995039.
- "Denmark Western Australia - Denmark River". 2007. Retrieved 5 October 2007.
- Toyah Shakespeare (4 August 2011). "Indigenous heritage protected". The West Australian. Yahoo7. Retrieved 28 May 2017.
- "Denmark River". InHerit. State Heritage Office. Retrieved 28 May 2017.
- "ABC News - Salinity drops in WA's Denmark River". 2004. Retrieved 8 June 2008.
- "Department of Environment - Denmark River Salinity Statement" (PDF). 2004. Retrieved 8 June 2008.
- Marmion, Bill (29 October 2012). "Salinity managed in Denmark River". Ministerial Media Statements. Government of Western Australia. Retrieved 24 November 2013.