Mary River

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

Flood Risk

The Mary River catchment is located in the southeast coastal area of Queensland and covers an area of over 7000 square kilometres. The headwaters of the Mary River are located in high rainfall areas around Maleny and Mapleton. Average annual rainfall in the Mary catchment ranges from around 2000 mm in the headwaters to around 1200 mm in the lower reaches of the catchment near Maryborough.

Flooding can cause extensive rural and property damage in the Mary River Valley. At Gympie, most floods have occurred due to heavy rainfall in the headwaters area between December and April. At Maryborough, floods are typically caused by heavy rainfall over the upper catchment, however, very heavy rainfall in the catchment area downstream of Gympie may also cause flooding at Maryborough.

Rainfall events that cause flooding in the Stanley and upper Brisbane rivers may also cause flooding in the upper Mary due to their shared catchment boundaries.

Significant rainfall over Munna Creek can result in large inflows that can impact Maryborough quickly (2013 Tropical Cyclone Oswald) although this is relatively uncommon.

Major flooding can also occur on Tinana Creek, which drains the eastern part of the catchment, arising in Noosa Hinterland and joining Mary River slightly upstream of Maryborough.

Flash flooding can occur at Wide Bay Creek, Six Mile Creek, as well as Myrtle Creek and Sandy Creek.

Previous Flooding

Gympie and Maryborough, the two main centres in the Mary River catchment, have a long history of flooding with detailed records available from 1910. Reports of major flooding prior to 1910 are available as far back as 1870. Significant floods include 1893, 1898, 1955, 1974, 1992, 1999, 2013, and 2022.

In 2022, major flooding in the Mary River occurred in two instances, in January and February. In January 2022, major flooding resulted from rainfall over the region associated with ex-Tropical Cyclone Seth. Localised but intense 24-hour rainfall totals in excess of 600 mm were recorded around Mt Kanigan. In February 2022, extreme and record-breaking multi-day rainfall across Southeast Queensland and northeast New South Wales resulted in the last week of February being the wettest week for these areas since at least 1900. This was driven by a combination of weather systems including a slow-moving high-pressure system to the southeast of Australia that maintained a humid onshore airflow into a persistent trough along the east coast of Australia. Extreme flash and riverine flooding occurred as a result, from Maryborough in Queensland to Grafton in New South Wales.

At Moy Pocket, the river level reached 10.23 m on 8 January 2022 and 16.13 m on 25 February 2022. The highest recorded flood peak is 16.80 m in February 1999.

At Dagun Pocket, the river level reached 13.14 m on 8 January 2022 and 17.47 m on 26 February 2022. The highest recorded flood peak is 18.43 m in February 1999.

At Gympie, the river level reached 13.61 m on 9 January 2022 and 22.96 m on 27 February 2022. This surpassed the February 1999 levels, making it the second highest flood peak recorded in Gympie and second only to the flood peak of 25.45 m recorded in February 1893.

At Miva, the river level reached 19.85 m on 8 January 2022 and 20.80 m on 27 February 2022. The highest recorded flood peak is 23.08 m in February 1893.

At Tiaro, a river level height of 20.73 m was recorded on 9 January 2022 and 19.90 m on 28 February 2022, noting that the lower peak in February may have been due to the timing of manual readings. The highest recorded flood peak is 21.95 m in February 1893.

At Maryborough, the river level reached 9.95 m on 9 January 2022 and 10.30 m on 28 February 2022. The highest recorded flood peak is 12.27 m in February 1893.

The table below summarises the flood history of the Mary River - it contains the flood gauge heights of some of the more significant flood peaks.

Flood Event	Moy Pocket (m)	Dagun Pocket (m)	Gympie (m)	Miva (m)	Tiaro (m)	Maryborough (m)
Feb 1893	-	-	25.45	23.08	21.95	12.27
Jan 1898	-	-	22.00	20.11	16.99	9.70
Mar 1955	-	-	21.44	21.84	20.75	11.23
Jan 1974	14.53	17.27	20.73	20.80	20.62	10.95
Feb 1992	14.22	17.39	21.44	20.45	18.60	9.50
Feb 1999	16.80	18.43	21.67	20.65	18.10	8.75
Jan 2011	9.70	-	19.45	19.80	17.00	8.20
Jan 2013	15.60	16.90	19.98	20.90	21.00	10.70
Feb 2022	16.13	17.47	22.96	20.80	19.90*	10.30

 

All heights are in metres on flood gauges.

*Higher levels were recorded in January 2022 of 20.73 m.