South East Queensland: Climate and water

  • Total annual rainfall was below average for the fifth consecutive year.
  • Heavy rainfall in February 2020 resulted in very high streamflows during that month.
  • Streamflows over the rest of the year were well below average.

 

Schematic representation of the South East Queensland region. In 2019–20, rainfall was 1,056 mm, less than average for the fifth consecutive year. Streamflow in Brisbane River in 2019–20 was 99 GL compared to the average value of 241 GL. Soil moisture was below average.

For further information on the region's climate and water conditions during the 2019–20 year scroll down this page or click on the links below:

 

About the region

  • The South East Queensland region has a subtropical climate. Rainfall occurs throughout the year with most rainfall occurring during the summer and autumn months. Higher streamflows typically occur during these months.

 

Climate conditions

Rainfall

Figure C1 Annual and monthly rainfall deciles for the South East Queensland region during the 2019–20 year

 

  • Total area-averaged rainfall for the year was 748 mm, well below the mean value of 1,056 mm, and lowest on record in some inland parts of the region.
  • This was the region's second consecutive year of very low rainfall. Over the last two years, the region has experienced its driest 24-month period since 1918–20.
  • Rainfall was very low during the latter half of 2019. The below-average rainfall throughout July–December 2019 was due to a positive phase of the Indian Ocean Dipole, one of the strongest on record, that influenced Australia's climate during this period (see the Bureau's 2019–20 Climate Report for more information).
  • There was some rainfall relief during the early part of 2020 as tropical moisture associated with warmer than average sea surface temperatures off the northwest coast of Australia moved across the continent and combined with southern cold fronts to produce high rainfall across the region.
  • Thunderstorms and showers associated with a near-stationary coastal trough over southeastern Queensland in early February 2020 contributed to the well above-average rainfall for that month.

 

Figure C2 Total monthly rainfall for the South East Queensland region during the 2019–20 year compared with the average and percentiles for the region

 

  • Rainfall was slightly above average in January 2020 and well above average in February 2020. All other months had below-average rainfall.
  • Rainfall in November 2019 was the second lowest on record for that month and the lowest in almost 70 years.

 

Actual evapotranspiration

Figure C3 Annual and monthly actual evapotranspiration deciles for the South East Queensland region during the 2019–20 year

 

  • Total area-averaged actual evapotranspiration was well below average across almost the entire region and lowest on record over inland areas of the region.
  • The very low annual evapotranspiration reflects the dry conditions and low water availability throughout most of the year.
  • Evapotranspiration was average over large parts of the region during February–April 2020 due to increased water availability following the high rainfall in February 2020.

 

Soil moisture

Figure C5 Annual and monthly soil moisture deciles for the South East Queensland region during the 2019–20 year

 

  • Soil moisture in the root zone (0–1 m depth) was below average across the region.
  • In July 2019, root-zone soil moisture was already below average over most of the region following a very dry 2018–19 year. Continued dry conditions during the latter half of 2019 meant that by December 2019, root-zone soil moisture was well below average and lowest on record over inland areas of the region.
  • Soil moisture was above average over large parts of the region during February–March 2020 following the high rainfall in February 2020.
  • More information on soil moisture distribution across the region is available in the Australian Landscape Water Balance.

 

Streamflow responses

Map of key gauging stations. North Maroochy River at Eumundi, station number 141009A, is located in the north of the region. Brisbane River at Gregors Creek, station number 143009A, is in the northwest of the region. Bremer River at Walloon, station number 143107A, is near the town of Ipswich. Logan River at Yarrahappini, station number, 145014A, and Albert River at Bromfleet, station number 145102B, are in the southern part of the region.
Figure C6 Key flow gauging stations along the main rivers within the South East Queensland region

 

  • The five main rivers in the region are the Albert, Brisbane, Logan, Bremer and Maroochy rivers.
  • The seasonal flow characteristics of these rivers reflect the rainfall pattern of the region, where most rainfall occurs between November and March.

 

Figure C6 Total monthly flow for major rivers in the South East Queensland region during the 2019–20 year compared with the average and percentiles

 

  • Streamflows were below average for most of 2019–20 reflecting the dry conditions experienced across the region. For example, total annual flow in the Brisbane River at Gregors Creek (Station 143009A) was 99 GL compared to the average value of 241 GL.
  • This was the second consecutive year of low streamflow in the region's rivers throughout most of the year.
  • Streamflow was particularly low during the latter half of 2019. In December 2019, there was no flow in any of the region's major rivers and no flow occurred in the Brisbane and Bremer rivers for the 7-month period between July 2019–January 2020.
  • Most of the annual flow in the region occurred during February 2020 following the above-average rainfall in that month. Streamflow in the Logan and Albert rivers, in the southern part of the region, was above the 90th percentile during February 2020, reflecting the higher rainfall that occurred in February over the upper reaches of these catchment areas.
  • Streamflow in the Bremer River during February 2020 was low compared to the other major rivers, which reflects the lower February rainfall over the river's catchment area in the central inland part of the region (see Rainfall).