Diamantina Rivers

This brochure describes the flood risk and previous flooding in the Diamantina River catchment, last updated in August 2025.

Flood Risk

The vast Diamantina River catchment is located in southwest Queensland and covers an area of approximately 119,000 square kilometres. The river rises in the Swords Range, 70 kilometres southwest of Kynuna and flows initially in a north and easterly direction before changing to a southwesterly direction 70 kilometres west of Winton. Major tributaries joining the river are the Western and Mayne Rivers above Diamantina Lakes and Farrars Creek below Monkira. The river does not have a well-defined main channel but consists generally of a series of wide, relatively shallow channels. The river passes through the town of Birdsville before crossing the Queensland-South Australia border 10 kilometres south of Birdsville.

Floods normally develop in the headwaters of the Diamantina River and in its major tributaries, however, flooding may result from heavy rainfall falling in the middle to lower reaches of the catchment around Diamantina Lakes. Local rainfalls can be a significant factor throughout these areas.

Major flooding requires a large-scale rainfall event over the Diamantina River catchment. The following can be used as a rough guide to the likelihood of flooding in the catchment:

75mm in 24 hours over isolated areas, with lesser rains of 50mm over more extensive areas will cause stream rises and the possibility of minor flooding. If lesser rainfalls have been recorded in the previous 24 to 72 hours, then moderate to major flooding may develop.

100mm in 24 hours will cause isolated flooding in the immediate area of the heavy rain.

General 100mm or heavier falls in 24 hours over a wide area will most likely cause major flooding in the middle to lower reaches of the Diamantina River between Tulmur and Diamantina Lakes extending downstream to Monkira and Birdsville.

Previous Flooding

The Diamantina River catchment has well documented history of flooding dating back some 50 years, including Diamantina Lakes (commenced 1965) and Birdsville (commenced 1949).

The main impact of the record major flooding in January 1974 at Birdsville, and more recently the floods of 1991, 1997, 1999, 2000, 2009, and 2025 is the isolation of towns and properties and the extensive inundation of grazing lands which can last several months in some areas, with road transport disrupted for considerable periods of time.

The table below summarises the flood history of the Diamantina River basin - it contains the flood gauge heights of the more significant recent floods.

Flood Event	Winton (m)	Elderslie (m)	Tulmur (m)	Diamantina Lakes (m)	Monkira (m)	Durrie Station (m)	Roseberth Station (m)	Birdsville (m)
Mar 1950	4.47*	-	-	-	5.79	-	-	8.54
Mar 1971	-	-	-	6.38	5.03	-	6.33	8.08
Jan/Feb 1974	4.53*	-	9.75	7.71	6.12	5.30	7.60	9.45
Feb 1976	-	-	-	7.29	5.25	3.90	6.50	8.20
Feb/Mar 1977	-	-	-	6.52	4.45	3.40	6.10	7.90
Feb 1991	-	-	-	6.40	4.80	4.30	6.40	8.20
Jan 1999	-	-	4.75	7.15	-	3.10	5.70	7.40
Feb/Mar 2000	4.65*	2.94	7.65	6.85	4.80	3.10	5.80	7.35
Jan 2004	2.90	3.65	6.25	-	5.00	-	-	8.20
Feb 2009	2.45	4.80	7.40	6.53	4.13	2.81	5.70	7.20
Mar 2010	-	-	-	3.81	4.10	3.25	5.96	7.90
Mar 2011	-	3.15	4.30	4.73	3.87	2.90	5.85	7.95
Feb 2012	2.40	3.60	-	5.05	3.55	-	-	-
Mar 2012	-	3.10	-	5.41	3.89	2.21	-	-
Mar 2018	3.70	4.50	7.70	6.93	4.30	2.00	5.23	5.98
Mar 2019	3.55	5.20	6.60	7.68	5.42	3.80	6.48	8.15
Mar/Apr 2025	3.30	3.10	-	7.54	5.39	4.50	6.95	8.75

 

All heights are in metres on flood gauges.

*Preliminary values subject to verification