Southern and Darling Downs regional water assessment

The Southern and Darling Downs region has a rich history of agricultural production with high utilisation of current water resources, particularly in the drier years. Also, the ability to meet urban water needs is already under pressure in the region.

The Southern and Darling Downs regional water assessment (RWA) was delivered in partnership under the National Water Grid Authority.

The assessment considers potential water sources across council and catchment boundaries to make the best use of existing infrastructure and identify new opportunities.

Through strong collaboration with local councils, industry, Sunwater, Seqwater, Traditional Owners and community members, 121 possible water initiatives were identified. After robust technical analysis and consultation, this list was reduced to the 9 most viable options for detailed assessment.

Public consultation helped refine the final RWA, which identifies short, medium and long-term recommendations to improve water security and drive economic growth.

The RWA can be considered as we deliver the state's wider water agenda.

Status

The final assessment was completed in early 2024.

View the Southern and Darling Downs RWA summary report (PDF, 9MB).

Consultation

Stakeholder advisory group consultation included:

  • AgForce Queensland
  • Border Rivers Commission
  • Border Rivers Food and Fibre
  • Cotton Australia (Queensland)
  • Goondiwindi Regional Council
  • National Water Grid Authority
  • Queensland Farmers Federation
  • Queensland Fruit and Vegetable Growers
  • Regional Development Australia (Darling Downs and South West)
  • Seqwater
  • Southern Downs Regional Council
  • Stanthorpe Community Reference Panel
  • Sunwater
  • Toowoomba Regional Council
  • Toowoomba Surat Basin Enterprise
  • Western Downs Regional Council.

Assessment area

View a map of the Southern and Darling Downs RWA area (PDF, 801KB).

Area summary

Local government areas

Includes Toowoomba Regional Council, Southern Downs Regional Council, Goondiwindi Regional Council and parts of Western Downs Regional Council.

Water context

The Southern and Darling Downs RWA area is largely within the Queensland Murray Darling Basin (QMBD) and includes the upper reaches of the Condamine River to the Chinchilla Weir water supply scheme (WSS), as well as border river catchments in the Goondiwindi and Southern Downs Regional Council areas. This area also includes the Upper Condamine, Macintyre Brook, Border Rivers and Cressbrook Creek WSSs. The QMBD is subject to commitments from multiple levels of government to not increase the amount of water taken. The RWA has also considered supply options from outside the RWA area to meet water needs in the region.

Snapshot of demographics

Population at the time of assessment ~250,000

Future population (by 2050) estimated at the time of assessment ~294,000

Main population centres

Toowoomba, Warwick, Dalby, Chinchilla, Goondiwindi, Stanthorpe

Smaller towns and cities

Oakey, Pittsworth, Crows Nest, Millmerran, Allora, Inglewood, Texas, Killarney, Talwood, Yelarbon, Dalveen, Emu Vale, Clifton, Cecil Plains, Bowenville

Key industries

Mining, construction and manufacturing and a range of agricultural industries including beef, broadacre, fodder, perennial horticulture, fruit and vegetables and intensive animal production

Agricultural land use

Grazing and dryland cropping. Irrigated broadacre crops dominate in Sunwater scheme areas

Main water sources

Leslie Dam, Coolmunda Dam, Glenlyon Dam, Perseverance Dam, Chinchilla Weir, Storm King Dam

Other water sources

Connolly Dam, Cooby Creek Dam, smaller dams and weirs, watercourses and groundwater systems

Water demand

Southern Downs local government area (LGA)

  • Irrigated broadacre cropping focused on areas with significant surface water supplies such as the Upper Condamine WSS.
  • The Granite Belt region contains a diverse mix of high value horticultural production, including apples, strawberries and grapes.
  • Groundwater is heavily relied on to supply feedlots, dairies and intensive agriculture.
  • Highly variable water security has resulted in significant fluctuations in economic prospects impeding investment to generate further economic activity and employment.
  • Water availability is a key impediment to future growth in agriculture.
  • Due to extreme drought, local water sources have not been able to meet urban water needs in recent years.

Toowoomba LGA

  • Toowoomba is expected to have significant growth in urban water demands in line with population growth.
  • Toowoomba Regional Council has identified a series of projects to ensure urban water security to mid-2040s. However, will likely require additional water supply to maintain water security after this.
  • The construction of a new pipeline is also expected to provide a permanent water supply for Cambooya, Greenmount, Nobby and Clifton communities.
  • Agricultural production includes cotton, broadacre crops, eggs, livestock and horticulture, with water sourced through water harvesting, overland flow or groundwater. Some water is also sourced from the Upper Condamine WSS and accessing releases from the Wetalla Water Reclamation Facility.

Goondiwindi LGA

  • Macintyre Brook and Border Rivers WSSs support irrigation of a variety of crops including lucerne, cereals, stone fruit and olives.
  • Overland flow and groundwater (largely from the Great Artesian Basin) supplies cotton, other broadacre crops and livestock production.
  • Minimal population growth in line with population estimates.
  • Hydrologic modelling shows that town water supplies for Goondiwindi and Inglewood are performing well, however, those for Texas and Yelarbon are less reliable with a greater reliance on groundwater sources to maintain water supplies.

Western Downs LGA

  • The area includes beef and pork production and large areas of cultivated cotton and other broadacre cropping.
  • Irrigators rely on a combination of overland flow, water harvesting and groundwater (largely from the Great Artesian Basin).
  • Chinchilla Weir WSS supports urban water demands for Chinchilla as well as irrigation of broadacre and horticultural crops, including melons.
  • While Chinchilla Weir has reached low levels on occasions, there is low likelihood of water supply failure before at least 2041 provided coal seam gas water continues to supplement the system sufficiently.
  • Dalby has experienced water security challenges in recent years due to low reliability of surface water and is heavily dependent on groundwater.

Options to support water security and economic growth

The assessment process identified the most suitable ways to support the region’s water security and promote economic growth.

The most promising options that have not been subject to recent detailed assessment or being examined as part of other initiatives were considered for further detailed assessment, with input from local stakeholders.

A summary of the options considered for further detailed assessment are provided below. Further details are available in the Southern and Darling Downs RWA summary report (PDF, 9MB).

Non-infrastructure options

Collaboration with New South Wales

Continued engagement with the New South Wales Government on water resource management in the Border Rivers region, to make sure there are good systems in place to manage water across borders. This could include water plans, water trading, drought planning or other options that would benefit both states.

Improved access to unallocated water

This option explored opportunities to improve access to existing unallocated water reserves in the region, particularly from the Queensland Murray Darling Basin deep groundwater aquifers which are located below the Great Artesian Basin.

Innovative solutions to reduce on-farm evaporation

This option investigated innovative solutions to reduce on-farm evaporation through increasing on-farm water storage efficiency. Four technologies investigated were shade cloth, floating covers, chemical formulations and structural amendments to existing dams.

Infrastructure options

Regional scale non-drinking recycled water for irrigation, industrial and greenspace use

Recycled water can generally be supplied irrespective of weather conditions. Depending on the how it is treated to meet end user requirements, it can cost less than drinking water. Five sub-options to expand current infrastructure and increase the volume of recycled water available were investigated:

  • Wetalla water reclamation facility located north of Toowoomba supplying recycled water for industrial users
  • Stanthorpe wastewater treatment plant located west of Stanthorpe supplying recycled water for horticulture and industry
  • Chinchilla recycled water scheme located west of Chinchilla supplying water for intensive agricultural use
  • Inglewood recycled water scheme located west of Inglewood supplying water for possible agricultural use
  • Warwick recycled water scheme located west of Warwick supplying water for intensive agricultural use.

Severn River off-stream storage and distribution network

This option considers building a new off-stream storage and distribution network to supply urban water to Stanthorpe and provide additional water for horticulture users on the Granite Belt.

Texas off-stream storage

A new off-stream storage near Texas to provide Goondiwindi Regional Council with a balancing storage to better manage access to existing surface water supply for Texas from the Dumaresq River. This option seeks to enhance urban water availability and security during drought periods.

Pipeline interconnection between Warwick and Stanthorpe

Construction of a new pipeline and upgrading existing pipelines to connect Stanthorpe to Warwick’s water supply via Connolly Dam. This option seeks to provide the Stanthorpe region with a secure urban water supply during severe droughts.

Glebe Weir off-stream storage and pipeline

This option considers building a new off-stream storage facility near Glebe Weir on the Dawson River, along with upgraded and new pipelines to supply water to support intensive animal production near Chinchilla.

Granite Belt irrigation project

This option investigates the construction of a water storage on the Severn River, called Emu Swamp Dam, along with a 117km water distribution network. This water could be used for irrigation and urban water supply for Stanthorpe.

Responding to the challenges and opportunities

Southern Downs LGA

Innovative solutions to reduce on-farm evaporation

  • Evaporation covers can help to maximise the efficiency of on-farm water storages, delivering positive economic and financial outcomes.
  • Shade cloth was considered the most suited to small irrigation dams and storages in the Granite Belt region, followed by floating covers.
  • Irrigation-based businesses may individually benefit from considering these evaporation covers to enhance water security and drought resilience of their agricultural operations.

Expansion of Warwick recycled water scheme

  • Would support local industrial and commercial water users and facilitate the growth of the agricultural sector.
  • Also considers the construction of a new transfer system to supply prospective intensive livestock development, which would be subject to further detailed analysis.

Pipeline between Warwick and Stanthorpe via Connolly Dam

  • Only option investigated that fully addresses Stanthorpe’s urban water security risk.
  • Given cost-effective short-term benefits of water carting this option does not present a strong economic and financial outcome in times of extreme drought.
  • Undertaking further detailed analysis would provide valuable information on the potential long-term urban water security solution for Stanthorpe.

Emu Swamp Dam

  • RWA investigations improved information on design and construction of Emu Swamp Dam substantially increased the Granite Belt irrigation project cost estimates.
  • Further work required to support any final investment decision including funding sources, geotechnical, water plan compatibility, securing water entitlements, pipeline alignment, hydrological and drought modelling, and design development.

Raising Storm King Dam

  • Could provide increased urban water security for Stanthorpe, enabling access to existing unallocated water reserve in the Stanthorpe water management area.
  • This option not considered in the RWA as it did not meet identified agricultural water demands.
  • Remains a potential future urban water supply option, but with potentially high cost.
  • Further work required to understand impacts on existing land holders and fish passage requirements.

Toowoomba LGA

Expansion of Wetalla Water Reclamation Facility

  • Could supply recycled water to surrounding industrial areas.
  • Further development of this option should consider Toowoomba Regional Council’s Water Vision 2071 and its underpinning analysis.

Wivenhoe Dam to Cressbrook Dam pipeline duplication

  • This option did not progress to further detailed analysis as part of the RWA, however, remains a potential urban water security option for Toowoomba.
  • Potentially high cost requiring further analysis on the effects on Southeast Queensland’s overall water security and pricing arrangements.
  • Pipeline alignment has several environmental and social challenges requiring further consideration.

Pipeline or supply sourced from Boondooma Dam

  • This option did not progress to further detailed analysis as part of the RWA, however, remains a potential urban water security option for Toowoomba.
  • Access to water allocations supporting the Tarong power station is required to enable the option and assumes there are no other demands or higher capacity to pay for the water.
  • Would require additional upgrades to Toowoomba’s existing water distribution network.
  • Potentially a high-cost option.

Goondiwindi LGA

Expansion of Inglewood recycled water scheme

  • Cost effective opportunity for local development.
  • Would maximise available climate resilient water supplies.

Texas off-stream storage

  • Provides for improved access to existing surface water sources.
  • Did not have a strong economic or financial outcome in part due to apparent benefits of a recently installed groundwater bore in Texas.
  • An audit of the reliability and quality of water available from the new groundwater bore is required prior to further progression of this option.

Collaboration with NSW to optimise Border Rivers water availability

  • Expected to improve stakeholder confidence in cross-border dialogue and enhance opportunities to identify and action initiatives to optimise water availability.

Western Downs LGA

Glebe Weir off-stream storage and pipeline

  • Further investigations required focusing on local water demands around Glebe Weir, including the Dawson Valley WSS and the Wandoan area.
  • Any progression of this option should be subject to outcomes of the Central Queensland RWA.

Expansion of Chinchilla recycled water scheme

  • Potentially a cost-effective opportunity for development to provide reliable water supply for local, high value, intensive animal production.
  • Would maximise available climate resilient water supplies.

Chinchilla off-stream storage

  • This option did not progress to further detailed analysis as part of the RWA, however, remains a potential urban water security option for Chinchilla.
  • Uncertainty surrounding the magnitude of the potential benefit that could be delivered by this option in addition to uncertainty of the water needs of Chinchilla in the broader regional context.

A water supply source from the Dawson Valley

  • The Nathan Dam and pipeline option did not progress to further detailed analysis as part of the RWA, due to significant geotechnical challenges and substantial high costs compared to other options.
  • Construction of Nathan Dam would inundate Glebe Weir.
  • Nathan Dam and other Dawson Valley options, will be considered further as part of the Central Queensland RWA.

Recommendations and implementation

The RWA prioritises recommendations for potential delivery over the next 30 years, to approximately the early 2050s. These recommendations were made at the time of the assessment (2024) and do not signify Queensland Government approval or funding. However, the key findings and recommendations will help to inform the delivery of the Queensland Government’s water agenda.

The recommendations provided below represent those at the time of assessment and do not include any announcements, decisions or activities (government or private) that may have been made since the completion of the Southern and Darling Downs RWA.

Short term

  • Initiate a detailed business case for the Warwick to Stanthorpe pipeline.
  • Explore opportunities to support local governments to expand non-potable recycled water networks:
    • Chinchilla recycled water scheme
    • Inglewood recycled water scheme
    • Warwick recycled water scheme
    • Wetalla water reclamation facility.
  • Develop an on-farm dam evaporation saving initiative for the Granite Belt region:
    • Complete an audit of existing storages, in consultation with relevant stakeholders, to more accurately identify and quantify those that may benefit from evaporation covers.
    • Identify preferred delivery arrangements, participation criteria and implementation approach for an evaporation saving initiative.
    • Subject to outcomes of the above steps, progress the preferred solution.

Medium term

  • Collaborate with the New South Wales Government on ways to optimise water availability in the Border Rivers.
  • Initiate detailed assessment of the Glebe Weir off-stream storage and pipeline augmentation, subject to outcomes of the Central Queensland RWA.
  • Undertake a post-implementation review of the on-farm dam evaporation saving initiative for the Granite Belt region.
  • Continue Granite Belt Irrigation Project development including geotechnical investigations, water plan compatibility and securing of necessary water entitlement, further hydrological and drought modelling, pipeline alignment and design development.

Long-term

  • Collaborate with the New South Wales Government on future water plan reviews in the Border Rivers region.
  • Deliver the Texas off-stream off-stream storage, subject to undertaking an audit of the reliability and quality of water supplies available from the new groundwater bore at Texas.

Enquiries

Please contact regionalwaterassessments@dlgwv.qld.gov.au