Border Rivers: Supporting information
- Below-average rainfall for most of the year contributed to very low outflows from the catchment into the Barwon River.
- End of year storage volume dropped to 53% full compared to 90% full last year.
- Total water use was much less than last year due to the dry conditions.
For further information on the region's water accounting statements scroll down this page or click on the links below:
Water storage
Storages
Figure S1 Total storage volume in the catchment at 30 June 2018 compared with the previous 8 years
- Total storage volumes decreased from 90% full at 30 June 2017 to 53% full at 30 June 2018.
- The decrease in storage volume was the catchment's first annual decrease in storage in four years.
Figure S2 Percentage-full volume on 30 June 2018 for each storage
- Storage volumes remained relatively steady above 85% full during the 2017 winter–spring months and then declined for the remainder of the year.
- More detailed information on the individual storages within the region is available on the Bureau of Meteorology's Water Storage website.
Rivers
- The volume of water in rivers at 30 June 2018 decreased from that at the same time last year, reflecting the drier conditions across the region late in the year.
Aquifers
- The volume of groundwater storage for the catchment represents sustainable diversion limit volumes as provided by the Murray–Darling Basin Authority.
- This volume remained constant during the year as there was no change in licences or the sustainable diversion limit.
Water flows
Surface water flows
Figure S3 Water inflows and outflows for the surface water store in the Border Rivers catchment during the 2017–18 year
- The largest natural surface water flow was runoff. Runoff was below average compared to previous years, which reflects the relatively poor rainfall conditions experienced across the region during the year (see Climate and water).
- The largest natural surface water outflows were evaporation and outflow. Outflow to the neighbouring Barwon River catchment was much lower than average due to the very dry conditions throughout the year.
Groundwater flows
Figure S4 Water inflows and outflows for the surface water store in the Border Rivers catchment during the 2017–18 year
- Groundwater movement across the region boundary as well as surface water–groundwater interactions are considered to occur within the region; however, these flows could not be quantified due to a lack of available data.
- Allocated water extraction by individual users made up almost 90% of the total extractions from the groundwater store.
Water accessibility
Figure S5 Water accessible volumes and use in the Border Rivers catchment for the years ending 30 June, from 2013–2018
- Surface water availability across the catchment was low in 2017–18 due to the dry conditions, which meant the surface water accessible volume for consumptive purposes, as well as held environmental water, decreased from last year. Actual surface water diversions were also much lower than last year.
- Groundwater accessible volumes remained unchanged from the previous two years.
- Groundwater extractions for consumptive use increased from last year, which was largely influenced by the drop in surface water availability across the region. The dry conditions meant users had to rely more on water supplied directly from the aquifers.
Water use
Figure S6 Water use in the Border Rivers catchment during the 2017–18 year
- Total water use in the catchment was 298,378 ML, mostly by individual users for agricultural and irrigation purposes.
- In addition to held environmental water, environmental surface water is delivered under plan provisions (estimated to be around 26 GL in 2017–18). Only held environmental water diversions are presented in this report.