Border Rivers: Climate and water
- Total annual rainfall was well below average for the second consecutive year.
- Streamflows were very low reflecting the below-average rainfall and poor soil moisture conditions.
- No flow occurred in the Dumaresq River for the entire year.
For further information on the catchment's climate and water conditions during the 2018–19 year scroll down this page or click on the links below:
About the catchment
- The Border Rivers catchment lies within the northeastern part of the Murray-Darling Basin.
- Average annual rainfall ranges from approximately 400 mm in the west to 800 mm in the east.
- The catchment's climate is sub-tropical. Rainfall occurs throughout the year with most rainfall occurring during the summer months. Higher streamflows typically occur during these months.
Climate conditions
Figure C1 Annual and monthly rainfall deciles for the Border Rivers catchment during the 2018–19 year
- Total area-averaged rainfall for the year was 377 mm, well below the mean value of 625 mm and the lowest since 1941–42.
- Most of the catchment experienced very dry conditions during the year. The majority of the Dumaresq River subcatchment area in the east experienced its lowest annual rainfall on record.
- Rainfall was very low across the region during January–February 2019, the typically wetter months of the year. Large parts of the catchment recorded their driest January and February on record.
- The below-average rainfall throughout the spring 2018 and winter 2019 months was likely due to a positive phase of the Indian Ocean Dipole that influenced Australia's climate during those periods (see the Bureau's 2018–19 Climate Report for more information).
- Well above-average rainfall occurred across parts of the catchment in October 2018 due to thunderstorm activity throughout the month.
Soil moisture
Figure C2 Annual and monthly soil moisture deciles for the Border Rivers catchment during the 2018–19 year
- Soil moisture in the root zone (0–1 m depth) was well below average across the catchment; some areas in the southern and eastern parts of the catchment experienced their poorest soil moisture conditions on record.
- Rainfall and soil moisture are typically closely aligned. For example, the very poor soil moisture conditions during January–February 2019 are due to the very low rainfall that occurred across the catchment during those months.
- Soil moisture conditions were below average across the catchment for almost the entire year.
- More information on soil moisture distribution across the catchment is available in the Australian Landscape Water Balance.
Streamflow responses
Figure C3 Key flow gauging stations along the main rivers within the Border Rivers catchment
- The Macintyre and Dumaresq rivers are two primary tributaries of the Barwon River. The upper reaches of these tributaries are relatively undisturbed.
- Streamflow in the lower Macintyre and Barwon rivers is influenced by dam operations and diversions for consumptive use.
Figure C4 Total monthly flow for major rivers in the Border Rivers catchment during the 2018–19 year compared with average and percentiles
- Streamflows were well below average for most of the year, which reflects the low rainfall and poor soil moisture conditions experienced across the region.
- Total annual flow in the Macintyre River at Goondiwindi (Station 416201A) was 158 GL compared to the average value of 995 GL. This was the river's lowest annual flow since 1994–95.
- Annual streamflow in the Dumaresq River was the lowest on record. No flow occurred in the river for the entire year, which reflects the record dry conditions over most of the Dumaresq River subcatchment area.