National Water Account 2017

South East Queensland: Climate and water

Annual rainfall in the region was below average for the second year in a row. The combination of relatively poor rainfall and soil moisture conditions contributed to below-average streamflows in the river systems for most of the year. Above-average streamflow only occurred in the southern part of the region for a brief period during March–April due to heavy rainfall associated with ex-tropical cyclone Debbie.

Diagram showing summary of rainfall, soil moisture and streamflow conditions for South East Queensland region for 2016–17

For further information on the region's climate and water conditions during the 2016–17 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 falling 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 2016–17 year

 

 

  • Total area-averaged rainfall was 945 mm, which is less than the mean annual rainfall of 1,056 mm.
  • Rainfall was below average for most of the year, except for a very wet March and above-average rainfall in August–September.
  • March rainfall was well above average due to heavy falls associated with ex-tropical cyclone Debbie.

 

 

Figure C2 Total monthly rainfall for the South East Queensland region during the 2016–17 year compared with the long-term average and percentiles for the region

 

  • In the first three months of year (July–September), the climate was influenced by a negative Indian Ocean Dipole phase that is associated with higher winter–spring rainfall. Rainfall across much of the region was above-average in August and well above-average in September.

 

Actual evapotranspiration


Figure C3 Annual and monthly actual evapotranspiration deciles for the South East Queensland region during the 2016–17 year

 

  • Total area-averaged actual evapotranspiration was 828 mm, less than the mean value of 852 mm.
  • Annual evapotranspiration was average to below average for most of the region, except for the Lockyer Valley and upper part of the Logan-Albert rivers catchment. In these areas, higher than usual rainfall in September and March increased the volume of water available for evapotranspiration. 

 

 

Figure C4 Total monthly actual evapotranspiration for the South East Queensland region during the 2016–17 year compared with the long-term average and percentiles for the region

 

  • Actual evapotranspiration was mainly below average during a 5-month period (November–March) when water availability was low. This was due to relatively poor rainfall during the spring and summer months of October–February.

 

Soil moisture

 


Figure C5 Annual and monthly soil moisture deciles in the root zone (0–1 m depth) for the South East Queensland region during the 2016–17 year

 

 

  • Soil moisture in the root zone (0–1 m depth) was average to below average across most of the region, except in the Lockyer Valley and Scenic Rim areas.
  • Rainfall and soil moisture are typically closely aligned. Above-average soil moisture during April reflects the above-average rainfall that occurred at the very end of March associated with ex-tropical cyclone Debbie, predominantly in the southern part of the region.
  • More information on soil moisture distribution across the South East Queensland region is available in the Australian Landscape Water Balance.

 

Streamflow responses

Streamflow

Figure C6 Map of key flow gauging stations along the main rivers within the South East Queensland 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 key rivers during the 2016–17 year compared with the long-term average and percentiles

 

  • Monthly flows were well below average for most of the year, except for March, when record high flows were observed in the Bremer and Logan rivers, and above-average flows were observed in the Albert River.
  • These high flows in March were primarily due to the well above-average rainfall associated with ex-tropical cyclone Debbie.
  • Total annual flows in the Bremer, Logan and Albert rivers were well above average as above-average rainfall in March occurred mainly in these catchments. Annual flows for the Brisbane and Maroochy rivers were similar to the long-term average.

 

Major water reforms