Burdekin
Supporting information
Introduction
The following set of notes provides consolidated reports for each of the water stores and systems within the Burdekin region during the 2013–14 year. The water stores and systems included in the region are shown in Figure 1.
For more information about the region, please refer to the General description section of the 'Contextual information'.
Figure 1 Water stores and systems within the Burdekin region
Information on all water flows to and from each water store and system are presented in this note, including between-store flows and transfers that are not presented in the water accounting statements. The between-store flows and transfers that occur in the region are presented in Figure 2.
Figure 2 Between-store flows that occur within the Burdekin region
The between-store flows and transfers (Figure 2), which are eliminated from the region's water accounting statements, are shown in italics throughout the following set of notes.
Surface water store
Surface water assets
The volume of significant surface water assets, including water held in storages, totaled 2,003,189 ML at the end of the 2013–14. The volume of water in regulated rivers, unregulated rivers, and lakes and wetlands could not be quantified due to a lack of available data; however, the volume of water held in channels and lakes is considered to be relatively small compared to the volume held in storages.
The location of each storage within the Burdekin region and the volume of water in each storage (including dead storage) as a percentage of total storage capacity at the end of the 2013–14 year is shown in Figure 3.
Figure 3 Percentage-full volume on 30 June 2014 for each storage
The overall storage volume within the Burdekin region was at 99% capacity at the end of the 2013–14 year, the same as it was at the start of the year. The water volume in all of the storages changed very little during the year (Figure 4).
Figure 4 Total volume of water in each storage within the Burdekin region at 30 June 2014 and 2013
Surface water liabilities
Surface water liabilities in the Burdekin region refer to the volume of surface water allocation remaining on licence entitlements at the end of the 2013–14 year for:
- individual users (0 ML)
- urban water system (0 ML)
- irrigation scheme (0 ML)
- inter-region transfer (0 ML).
Most of the water supply licences for the region have a water management year that ends on 30 June. Therefore, the volume of allocation remaining at the end of the 2013–14 year for the Burdekin region, which represents the unused component of the annual allocation for these licence entitlements, is zero.
The allocation remaining for each licence entitlement is provided in tables 1–4.
| Account: Individual users | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Surface water allocation announcements | 468,730 |
| Entitled diversion of allocated surface water to individual users | (322,657) |
| Adjustment and forfeiture of surface water allocation | (146,073) |
| Closing balance at 30 June 2014 | 0 |
| Account: Urban water system | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Surface water allocation announcements | 1,785 |
| Entitled diversion of allocated surface water to urban water system | (785) |
| Adjustment and forfeiture of surface water allocation | (1,000) |
| Closing balance at 30 June 2014 | 0 |
| Account: Irrigation scheme | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Surface water allocation announcements | 637,457 |
| Entitled diversion of allocated surface water to irrigation scheme | (542,890) |
| Adjustment and forfeiture of surface water allocation | (94,567) |
| Closing balance at 30 June 2014 | 0 |
| Account: Inter-region transfer | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Surface water allocation announcements | 32,121 |
| Surface water transfer under inter-region commitment | (8,976) |
| Adjustment and forfeiture of surface water allocation | (23,145) |
| Closing balance at 30 June 2014 | 0 |
Surface water inflows and outflows
A schematic diagram representing all the inflows and outflows associated with the surface water store in the Burdekin region is provided in Figure 5.
Figure 5 Water inflows and outflows for the Burdekin region's surface water store during the 2013–14 year
Surface water inflows
The largest water inflow into the surface water store is runoff (3,510,350 ML). The remaining two natural surface water inflows are precipitation on surface water (87,791 ML) and groundwater discharge (– ML). The volume of precipitation represents rainfall that fell on the storages within the region; the groundwater discharge volume represents the volume of water discharged from the Burdekin region's aquifers to rivers. The volume of groundwater discharge cannot be quantified accurately due to a lack of available data.
The two transfers of water in the region are point return from the irrigation scheme (– ML), which represents return flow from the irrigation areas to rivers, and treated wastewater discharge by other users (– ML). Both of these transfers are not measured and cannot be quantified accurately.
Surface water outflows
The largest water outflow is the river outflow from the region (1,862,192 ML), which refers to the annual volume of flow from the Burdekin River (1,493,849 ML), Haughton River (250,489 ML) and Barratta Creek (117,854 ML) into the South Pacific Ocean during the 2013–14 year. Evaporation from surface water during 2013–14 year was 310,309 ML.
Non-allocated surface water diversions to individual users in the region was estimated to be 92,117 ML during the 2013–14 year, which assumes 100% of the licenced entitlement was taken. Allocated water diversions from the surface water store are described in Surface water allocation diversions below.
The total annual leakage from surface water storages within the Burdekin region and the volume of river and floodplain losses cannot be quantified accurately due to a lack of available data; however, the river losses are considered to be relatively large and its omission may have a material impact on the water balance of the surface water store (see Balancing item).
Surface water allocation diversions
Most of the entitled diversion of allocated surface water in the Burdekin region is for irrigation scheme water supply. During the 2013–14 year, 542,890 ML of surface water was diverted from storages to the Burdekin and Bowen irrigation areas (Figure 6), which accounts for approximately 62% of the total allocation diversion.
Figure 6 Surface water allocations and diversions for irrigation and inter-region transfers
Entitled diversion of allocated surface water for individual users during the 2013–14 year was 322,657 ML, which accounts for approximately 37% of the total allocation diversion. Licences primarily relate to water sourced for the industrial and mining sectors (see Surface water allocation announcements below).
Entitled diversion of allocated surface water for urban water supply during the 2013–14 year was 785 ML, which accounts for less than 1% of the total allocation diversion. This volume only includes town water supply associated with the Bowen Broken Water Supply Scheme; surface water supply volumes to towns outside of this scheme, such as Charters Towers, were not available at the time this account was compiled. It is likely that the reported volume of surface water diversion for urban water supply is underestimated by more than 5,000 ML.
Inter-region transfers of surface water from the region include water transferred via the Paluma Crystal Creek scheme and the Burdekin Haughton Water Supply Scheme (Figure 6) to the headwaters of Crystal Creek and Ross River respectively; both of which are located outside the Burdekin region boundary. These transfers are used to supplement water supply for Townsville. Total allocated diversions for the 2013–14 year from these schemes was 8,976 ML, approximately 1% of the total allocation diversion. The reported inter-region transfer volume does not include two pipeline systems from the Eungella Dam and Burdekin River, which transfer surface water to Moranbah located outside the region in the adjacent Fitzroy River catchment. These systems have the capacity to supply 23,000ML and 21,200ML of water to Moranbah per year respectively; however, at the time of compiling this account inter-region transfers to Moranbah could not be quantified.
Surface water forfeitures
The portion of surface water allocation that has not been abstracted at the end of the water year is forfeited, that is, there is no carry-over of entitlements into the next water year. Water forfeitures in the Burdekin region during the 2013–14 year relate to licence entitlements for:
- individual users (146,073 ML)
- urban water system (1,000 ML)
- irrigation scheme (94,567 ML)
- inter-region (23,145 ML).
Surface water allocation announcements
Water allocation announcements in the Burdekin region during the 2013–14 year refer to surface water supply to:
- individual users (468,730 ML)
- urban water system (1,785 ML)
- irrigation scheme (637,457 ML)
- inter-region (32,121 ML).
Individual users in the region primarily source water for industrial and mining purposes. The urban water supply licences relate to town supply for Collinsvale, Scottville and Glenden. The irrigation scheme licences relate to the Burdekin River and the Bowen River irrigation areas. The annual allocation announcement and diversion for each irrigation area during the 2013–14 year is shown in Figure 6.
The inter-region licences relate to water transferred via the Paluma Crystal Creek scheme and the Burdekin Haughton Water Supply Scheme to the headwaters of Crystal Creek and Ross River respectively; both of which are located outside the Burdekin region boundary. The annual allocation announcement and diversion for each of these inter-region transfers during the 2013–14 year are shown in Figure 6. As discussed in Surface water allocation diversions, the inter-region allocation does not include the two pipeline systems from the Eungella Dam and Burdekin River, which transfer surface water to Moranbah located outside the region in the adjacent Fitzroy River catchment.
A more detailed description of surface water allocations and associated water rights in the Burdekin region is given in the Surface water rights note.
Surface water balancing item
The balancing item volume represents the difference between the measured opening and closing balances of the surface water store, after physical inflows and outflows have been applied. This item is an indication of both the accuracy of the volumes reported and the degree to which the reported water flows represents a complete surface water store balance.
The balancing item is calculated according to Table 5.
| Account: Surface water store | Volume (ML) |
| Opening balance (1 July 2013) | 2,003,839 |
| Total surface water inflows | 3,598,141 |
| Total surface water outflows | (3,139,926) |
| Closing balance (30 June 2014) | (2,003,189) |
| Balancing item | (458,865) |
The calculation of the water balance on the surface water store yielded a balancing item of -458,865 ML. This is approximately 23% of the total surface water store volume at the end of the 2013–14 year and approximately 13% of the total surface water inflows during the 2013–14 year. The negative balancing item indicates that either the inflows are too high or the outflows are too low.
The balancing item is primarily attributed to the fact that river and floodplain losses cannot be quantified in the account. It is likely that these losses are a relatively large source of surface water decrease throughout the region.
Runoff to surface water, which is a large source of surface water increase, is partly derived from a rainfall–runoff model (see Quantification approaches) and it is reasonable to expect a 10–20% uncertainty around the estimated portion of the runoff volume (+/– 300,000 ML).
The balancing item is also attributed to uncertainty associated with river outflow from the region (a large source of surface water decrease). The river outflow to sea is based on measured flow data collected at the most downstream station along a river. There is no adjustment made for the contributing area below the gauging station (see Quantification approaches). As such, outflow to sea is likely to be underestimated by 10–20% (300,000 ML).
Groundwater store
Groundwater assets
The aquifers in the Burdekin region are described in the Groundwater section of the 'Contextual information'. While some information exists on water movement to and from the aquifers (see Groundwater inflows and outflows below), no value is available for the volume of water stored in the aquifers as indicated by dashes ('–') in the water accounting statements.
Groundwater liabilities
Groundwater liabilities in the Burdekin region refer to the volume of groundwater allocation remaining on licence entitlements at the end of the 2013–14 year for:
- individual users (0 ML)
- urban water system (0 ML)
- irrigation scheme (0 ML).
Most of the water supply licences for the region have a water management year that ends on 30 June. Therefore, the volume of allocation remaining at the end of the 2013–14 year for the Burdekin region, which represents the unused component of the annual allocation for these licence entitlements, is zero.
The allocation remaining for each licence entitlement is provided in tables 6–8. Note that the allocation announcement and entitled extraction volumes associated with individual users and town supply (tables 6 and 7) have been estimated. No data were available for these items at the time this account was compiled.
| Account: Individual users | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Groundwater allocation announcements | 10,000 |
| Entitled extraction of allocated groundwater to individual users | (5,000) |
| Adjustment and forfeiture of groundwater allocation | (5,000) |
| Closing balance at 30 June 2014 | 0 |
| Account: Urban water system | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Groundwater allocation announcements | 10,000 |
| Entitled extraction of allocated groundwater to urban water system | (5,000) |
| Adjustment and forfeiture of groundwater allocation | (5,000) |
| Closing balance at 30 June 2014 | 0 |
| Account: Irrigation scheme | Volume (ML) |
| Opening balance at 1 July 2013 | 0 |
| Groundwater allocation announcements | – |
| Entitled diversion of allocated groundwater to irrigation scheme | (–) |
| Adjustment and forfeiture of groundwater allocation | (–) |
| Closing balance at 30 June 2014 | 0 |
Groundwater inflows and outflows
A schematic diagram representing all the inflows and outflows associated with the groundwater store in the Burdekin region is provided in Figure 7.
Figure 7 Water inflows and outflows for the Burdekin region's groundwater store during the 2013–14 year
The only inflow to the groundwater store in the Burdekin region that can be quantified is the managed aquifer recharge from individual users (34,275 ML). The only outflows from the groundwater store that can be quantified are the groundwater extractions. Non-allocated groundwater extractions to individual users in the region was estimated to be 35,072 ML during the 2013–14 year, which assumes 100% of the licensed entitlement was taken. Allocated water extractions from the groundwater store are described in Groundwater allocation extractions below.
Natural 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, as indicated by dashes ('–') in Figure 7.
Groundwater allocation extractions
At the time of compiling this pilot account, allocated groundwater extraction volumes across the Burdekin region could not be quantified accurately due to a lack of available data.
In this account, entitled extraction of allocated groundwater for individual use and urban water supply were estimated for the 2013–14 year to be approximately 5,000 ML respectively. Total groundwater extracted for irrigation scheme supply during the 2013–14 year (– ML) cannot be quantified accurately due to a lack of available data.
Recent studies have indicated that total annual groundwater extraction across the Burdekin Groundwater Management Area (BGMA) are approximately 49,000–93,000 ML per year (Bennet, 2013). (McMahon, 2011) used an average pumped volume of 70,000 ML year for the area. Numerical modelling undertaken by (Arunakumaren 2001) for the Lower Burdekin area estimate extractions of around 200,000–500,000 ML per year.
Groundwater forfeitures
The portion of groundwater allocation that has not been abstracted at the end of the water year is forfeited, that is, there is no carry–over of entitlements into the next water year. Water forfeitures in the Berdekin region during the 2013–14 year relate to licence entitlements for:
- individual users (5,000 ML)
- urban water system (5,000 ML)
- irrigation scheme (– ML).
Groundwater allocation announcements
Groundwater allocation announcements in the Burdekin region during the 2013–14 year refer to groundwater supply to:
- individual users (10,000 ML)
- urban water system (10,000 ML)
- irrigation scheme (– ML).
Groundwater allocations for individual use and urban water supply were estimated for the 2013–14 year to be approximately 10,000 ML and 10,000 ML respectively. These volumes were not available at the time the account was compiled. Total groundwater allocation for irrigation within the region for the 2013–14 year (– ML) also cannot be quantified accurately due to a lack of available data.
Groundwater allocations and associated water rights in the Burdekin region are given in the Groundwater rights note.
Groundwater balancing item
The balancing item volume represents the difference between the measured opening and closing balances of the groundwater store, after physical inflows and outflows have been applied. Given the volume of water in the aquifers and the natural groundwater movement in the region cannot be quantified, the balancing item is simply the difference between the managed aquifer recharge from individual users (34,275 ML) and the total volume of groundwater extraction (45,072 ML), as shown in Table 9.
| Account: Groundwater store | Volume (ML) |
| Opening balance at 1 July 2013 | – |
| Total groundwater inflows | 34,275 |
| Total groundwater outflows | (45,072) |
| Closing balance at 30 June 2014 | – |
| Balancing item | 10,797 |
Unaccounted-for difference
The volume recognised in the water accounting statements (1,929,678 ML) represents the total unaccounted-for difference for the Burdekin region for the 2013–14 year.
The unaccounted–for difference is the volume necessary to reconcile the opening water storage and closing water storage with the total water inflows and total water outflows reported in the water accounting statements. It is calculated according to Table 10.
| Account: Water storage | Volume (ML) |
| Opening water storage balance (1 July 2013) | 2,003,839 |
| Total water inflows | 3,632,416 |
| Total water outflows | (3,184,998) |
| Closing water storage balance (30 June 2014) | (2,003,189) |
| Unaccounted-for difference | (448,068) |
The unaccounted–for difference can also be calculated by summing the volumes necessary to reconcile (balance) the opening and closing storage with the water inflows and outflows of each of the separate water stores of the region, as shown in Table 11.
| Balancing item | Volume (ML) |
| surface water store | (458,865) |
| groundwater store | 10,797 |
| Unaccounted-for difference | (448,068) |
The unaccounted–for difference volume is almost entirely attributed to the balancing item of the surface water store. Details regarding the balancing item's calculation are given in the Surface water store note.
The volume of water in the groundwater stores within the Burdekin region could not be quantified.