South East Queensland
Future outlook

Table 1 shows that there is a surplus of available water assets over water liabilities and future commitments that are expected to be settled within 12 months of the reporting date.

The expected diversions and extractions are based on abstractions made during the current reporting period 2013–14, which may be higher than normal due to the dry year and increased irrigation and outdoor urban demand. Low rainfall in the 2013–14 year (refer to the Climatic overview) produced low streamflows and consequently low volume of water stored in the surface water storages within the region.  If low rainfall persists into 2014–15, it is expected that the water sharing rules in the Moreton, Logan Basin and Gold Coast ROPs may result in less than 100% allocation announcement for all water supply schemes within the region for the 2014–15 year.

The purpose of this note is to report on possible water assets and possible water liabilities for the SEQ region. Possible (or contingent) water assets and water liabilities arise from past events and may be confirmed if future events not fully under the control of the management of the region occur.

Desalinated water

The Gold Coast desalination plant officially became part of the SEQ water grid on 30 September 2011 and is owned by Seqwater. Desalinated water from the Gold Coast desalination plant, in Tugun, is blended with other water supplies before it joins the SEQ water grid. Seqwater works closely with all entities to determine the demand on the desalination plant through a grid instructions process. Under normal operating conditions, it was planned for the desalination plant to operate at a minimum of 33% capacity (44 ML/day) in accordance with rules outlined in the 'SEQ System Operating Plan v. 3.1'. With the region's storages full or near full, the SEQ water grid has been operating in 'hot stand–by' mode to minimise operating costs since December 2010. Under this mode of operation, the plant will typically produce around 25 ML/day of water two days a week, with no production in between. This small amount of production is needed to keep the membranes wet and the water in the pipes fresh, while retaining the capacity to ramp up to produce 44 ML/day (33%), 88 ML/day (66%) or 133 ML/day (100%) within hours whenever required.

The plant may be called on if there are interruptions to supply in other parts of the SEQ water grid, as occurred in the January floods and in lighting strikes that temporarily knocked out the Mount Crosby WTP. The plant will also cover production when other parts of the water grid are offline for routine maintenance or due to water quality issues.

The contingent water asset associated with the Gold Coast desalination plant is the difference between the maximum operating capacity (133 ML/day) and the minimum operating rate (7 ML/day average based on hot–standby mode) and equates to 126 ML/day.

The non–extractable portion of groundwater

The GMA of the Lockyer Valley located within the Moreton WRP area was the only aquifer included as a store in the water accounting statements. Within the benefitted area of the Central Lockyer Valley WSS, a groundwater limit exists, which defines the entitled maximum volume that can be extracted from the benefitted area of the aquifer as 9,340 ML.

The remaining portion of the groundwater within the Lockyer Valley and all other groundwater within the SEQ region is considered a contingent water asset.

A model was developed within the former DERM to estimate the total volume of water in Implementation Area 1 of the Lockyer Valley GMA. This model is now managed by DNRM and/or DEWS. The total volume of water in Implementation Area 1 was computed by the model to be 102,345 ML at 30 June 2011, an increase of 24,466 ML on 30 June 2010 total volume of 77,879 ML. There were no updates on volume of water in the 2013 and 2014 year accounts.

Groundwater aquifers do occur elsewhere within the SEQ region. DNRM is investigating methods to estimate aquifer storage volumes and it is anticipated that estimates will become available in future water accounts.

It is possible that a change in circumstances, including legislative or regulatory changes that alter the extraction limits, such as the setting of volumetric extraction limits within the non-benefitted area of the Lockyer Valley groundwater aquifer, would result in further portions of the groundwater being included as an asset. There is no estimate available of the total volume stored in groundwater aquifers of the SEQ region.

Inter-region claim on water sources within the SEQ Water Grid

The SEQ water grid extends beyond the north and east boundaries of the SEQ region. It includes part of the Mary WRP area (Sunshine Coast) and Stradbroke Island. Although entitlements for both supplemented and unsupplemented surface water and groundwater are controlled by Seqwater in the Mary WRP area and Stradbroke Island, the volume of water to be transferred is not under control.

Water diverted or extracted based on these entitlements may, after treatment, be transferred into the SEQ region. As the volume transferred into the region will be determined by region resources, consumer demand and operational policy of the SEQ water grid, water diverted or extracted on these entitlements would be considered a contingent water asset for the region. As it is unknown what proportion of the entitlements can or may be transferred into the region, an estimate of the contingent water asset can not be made.

Water for urban use (263,380 ML): Urban retailers within the SEQ region, including QUU, Unitywater, and various regional councils, supply potable, nonpotable and recycled water to residential customers throughout the region. These urban retailers maintain water within their distribution pipes for the delivery of water to customers but the actual delivery of water is determined by the customers when they turn on the tap. Therefore, the delivery of potable water to customers within the SEQ region is considered a contingent liability. During the 2013–2014 year, 238,016 ML of potable and nonpotable water was delivered to customers of the SEQ. In addition, 25,364 ML of recycled water was supplied to customers out of which 1,282 ML was advanced treated recycled water supplied to power stations within the region.

Notwithstanding any major changes, it is estimated that a similar volume of water will be required to be delivered in the next reporting period.

Surface water and groundwater water for private use (9,326 ML): The ROL holders (Seqwater and Toowoomba Regional Council) allocate water to non-urban supplemented entitlement holders; however, the actual delivery of the water is contingent on the customers when they divert the water. Therefore the delivery of non-urban supplemented water to customers within the SEQ region is considered a contingent liability. During both the 2012–13 year  and 2013-14 year, 5,986 ML of supplemented surface water was delivered to customers. During the 2013–14 year, 3,340 ML of groundwater was delivered to the benefitted area of the Central Lockyer WSS, compared with 2,078 ML in the 2012–13 year.