Fitzroy: Climate and water

  • Total annual rainfall was below average for the fourth consecutive year.
  • The dry conditions resulted in low streamflows for most of the year.

Schematic representation of the Fitzroy region. In 2020–21, rainfall was 494 mm, less than average for the fourth consecutive year. Streamflow in Fitzroy River in 2020–21 was 390 GL compared to the average value of 4,933 GL. Soil moisture was below average.

For further information on the region's climate and water conditions during the 2020–21 year scroll down this page or click on the links below:

 

About the region

  • The Fitzroy region has a sub-tropical, semi-arid climate with a high inter-annual variability in rainfall and streamflow.
  • Most of the rainfall occurs during the wet season (November–April). As a consequence, flow in the rivers is strongly seasonal and many of the region's rivers cease to flow during the dry season (May–October).

 

Climate conditions

Rainfall

Figure C1 Annual and monthly rainfall deciles for the Fitzroy region during the 2020–21 year

 

  • Total area-averaged rainfall for the year was 494 mm, well below the mean value of 674 mm.
  • This was the region's fourth below-average rainfall year and third consecutive year of well below-average wet-season rainfall. Over the last three years, the region has experienced its second driest 36-month period in the last 100 years of record.
  • Although climate across most of northern Australia was influenced by moderate La Niña conditions in the Pacific Ocean, much of the above-average rainfall occurred over the Top End of the Northern Territory and northern Western Australia; less rainfall was experienced over Queensland.
  • Heavy rainfall associated with a coastal trough over southeastern Queensland in late-March 2021 contributed to the above-average rainfall for that month, particularly in the southern part of the region.

 

Figure C2 Total monthly rainfall for the Fitzroy region during the 2020–21 year compared with the average and percentiles for the region

 

  • Rainfall was generally below average throughout the 2020–21 wet season (November–April). Rainfall was only above average in March 2021.

 

Actual evapotranspiration

Figure C3 Annual and monthly actual evapotranspiration deciles for the Fitzroy region during the 2020–21 year

 

  • Total area-averaged actual evapotranspiration was below average across most of the region.
  • Evapotranspiration was well below average across large parts of the region in December 2020 due to low water availability following poor early wet-season rainfall in November 2020.
  • Evapotranspiration was above average over southern parts of the region in April 2021 due to increased water availability following high rainfall in late-March 2021.

 

Soil moisture

Figure C4 Annual and monthly soil moisture deciles for the Fitzroy region during the 2020–21 year

 

  • Soil moisture in the root zone (0–1m depth) was below average across most of the region.
  • Very low rainfall during the previous 24-month period between 2018–20 meant root-zone soil moisture was below average during the latter half of 2020. By December 2020, soil moisture was below average across almost the entire region.
  • Soil moisture was above average over some parts of the region during April 2021 due to high rainfall in late-March 2021; however, low rainfall late in the wet season meant that by June 2021 soil moisture had returned to below average conditions.
  • More information on soil moisture distribution across the Fitzroy region is available in the Australian Landscape Water Balance.

 

Streamflow responses

Map of key gauging stations. Nogoa River at Craigmore, station number 130209A, approximately 40 km upstream of Fairbairn Dam. Comet River at The Lake, station number 130506A. Dawson River at Taroom, station number 130209A, in the south near Taroom. Isaac River at Yatton, station number 130401A, in the north. Mackenzie River at Coolmaringa, station number 130105A, approximately 100 km west of Rockhampton. Fitzroy River at The Gap, station number 130005A, approximately 50 km upstream of Rockhampton.
Figure C6 Key flow gauging stations along the main rivers within the Fitzroy region

 

  • The six main rivers in the region are the Fitzroy, Dawson, Nogoa, Mackenzie, Isaac, and Comet rivers, which correspond to the six sub-basins used for environmental water management (see the Water management section in 'Region description' for more information).

 

Figure C7 Total monthly flow for major rivers in the Fitzroy region during the 2020–21 year compared with the average and percentiles

 

  • Streamflows were below average for most of 2020–21, reflecting the dry conditions experienced across the region. For example, total annual flow in the Fitzroy River at the Gap (Station 130005A) was 390 GL compared to the average value of 4,933 GL.
  • This was the fourth consecutive year of low flows in the region's rivers throughout most of the year.
  • Streamflows in the Nagoa and Dawson rivers, in the southern part of the region, were above average during March 2021, reflecting the higher rainfall that occurred in that month over the upper reaches of these catchment areas.