Border Rivers: Climate and water
- Total annual rainfall was well below average and the lowest since 1964–65.
- Some parts of the catchment experienced their lowest annual rainfall on record.
- The relatively poor rainfall resulted in very low flows across the region and groundwater levels dropped to their lowest in seven years.
For further information on the catchment's climate and water conditions during the 2017–18 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 2017–18 year
- Total area-averaged rainfall for the year was 423 mm, well below the mean value of 629 mm and the lowest since 1964–65.
- Most of the catchment experienced very dry conditions during the year, with some areas in the Queensland part of the region experiencing their lowest annual rainfall on record.
- Heavy rainfall across the region associated with a low level trough and upper level low during October 2017 contributed to above-average rainfall for that month. Some areas west of Goondiwindi experienced their highest rainfall on record for that month.
- Except for October 2017 and February 2018, rainfall was average to below average for most of the year.
- Similar to rainfall, soil moisture in the root zone (0–1 m depth) was well below average in 2017–18 across most of the catchment. More information on soil moisture distribution across the catchment is available in the Australian Landscape Water Balance.
Hydrological responses
Streamflow
Figure C2 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 C3 Total monthly flow for major rivers in the Border Rivers catchment during the 2017–18 year compared with average and percentiles
- Streamflow in the catchment's major rivers were well below average for almost the entire year, which reflects the low rainfall across the region during most of the year.
- The heavy rainfall event in October 2017 had little affect on streamflows in the lower Macintyre and Dumaresq rivers due to very poor soil moisture conditions in these areas prior to the rainfall event.
- In contrast, streamflow in the upper Macintyre River during October 2017 was above average. Soil moisture conditions in the upper reaches of this tributary prior to the rainfall event were near average and less dry than the remainder of the Border Rivers catchment.
Groundwater levels
- Groundwater is mainly extracted from alluvial sources. These sources are more sensitive to variation in rainfall and streamflows than the other groundwater sources.
Figure C4 Groundwater levels in monitoring bores in the Queensland Border Rivers alluvium during the 2017–18 year compared with average and percentiles
- Groundwater levels steadily declined for almost the entire year due to the very poor rainfall conditions across the catchment during 2017–18.
- During October–November 2017, groundwater levels at the monitoring bore near Texas were relatively steady following above-average rainfall in October.
- At the end of June 2018, groundwater levels were at their lowest since since February 2011.