FAQ: Roper River Water Resource Assessment
The aim of the Roper River Water Resource Assessment is to provide information and analysis about the catchment as a whole, to inform public discussion and decisions around potential development.
Most of northern Australia's land and water resources have not been mapped in enough detail to provide for reliable resource allocation, to understand and mitigate risks (including investment, environmental and social risks), or to build policy settings that can support decisions.
The Assessment undertook a comprehensive and integrated evaluation of the feasibility, economic viability and sustainability of water resource development in the Roper River catchment. The report is presented in a way that’s consistent with past assessments to better enable direct comparisons between other areas assessed across northern Australia.
The Assessment was funded through the National Water Grid’s Science Program, which provided $5.2 million in funding from 2019 to 2024. The National Water Grid sits within the Australian Government’s Department of Climate Change, Energy, the Environment and Water (DCCEEW).
The Assessment produced 12 technical reports, the key findings of the technical reports are summarised in a 506-page catchment report. The key findings in the catchment report have been further distilled into a 28-page summary report and a two-page factsheet. All reports are freely available for download on our Roper River Water Resource Assessment website.
The Assessment:
- Evaluated the soil and water resources (both surface and groundwater).
- Identified and evaluated water capture and storage options.
- Identified and evaluated the commercial viability of irrigated agriculture opportunities.
- Assessed the potential environmental, social and economic impacts and risks of water resources and irrigation developments.
In practice, the Assessment adopted an activities-based approach to investigate the following areas: climate; land suitability; surface water hydrology; groundwater hydrology; agriculture viability; water storage; socio-economics; Indigenous values, rights and development objectives; and aquatic and marine ecology.
No. The Assessment does not advocate for water resource and irrigation development. Nor does it undertake to assess or enable any particular development.
The nature and scale of any future development will depend heavily on government and community values, to weigh the potential impacts on water-dependent ecosystems and existing water users. Land tenure, land ownership and use, flooding risk, availability and proximity of water for irrigation, and other factors will also impact the plausibility of potential developments.
The Assessment is fundamentally a resource evaluation, which shows the upper limit of what might be biophysically possible. It identifies what resources could be deployed for potential irrigation enterprises. It also evaluates the feasibility of development (at a catchment level) and considers the overall scale of the opportunities and impacts that might exist.
In doing so, the Assessment examined key economic, social, cultural and environmental values associated with existing use of those resources, to enable a wide range of stakeholders to assess for themselves the costs and benefits of given courses of action.
Importantly, the Assessment does not replace any planning processes. Nor does it seek to recommend changes to existing plans or planning processes.
The Assessment was led and conducted primarily by CSIRO. We worked closely with Northern Territory Government agencies, universities, private sector consultants and research providers, local communities and key industry partners.
In all, more than 60 experts from CSIRO and other research partners were involved over a four-year period.
The Assessment provides a trusted information base to enable governments, industries and communities to participate in debate and make informed decisions about sustainable water resource development in the Roper River catchment.
The results can be used to inform resource planning, management, and investment decisions by a wide range of interested people. This includes Traditional Owners, land holders, non-government organisations involved in natural resource management, economic development and environmental protection advocacy groups, corporate and non-government investors, and the different tiers of government – local council, state and territory governments, and the Australian Government.
The Assessment highlights that understanding how diverse stakeholder, investor and developer perspectives interact will be crucial in building and maintaining an ongoing social license to operate for future water and agricultural developments.
Yes. Indigenous people represent a substantial and growing proportion of the population across northern Australia and control significant natural and cultural resource assets, including land, water, and coastlines. They are crucial owners, partners, investors, and stakeholders in future development.
A key component of the Assessment involved research on Indigenous water values, rights, interests and development objectives. The primary participants in Indigenous consultations were representatives of Traditional Owner corporations - particularly native title Prescribed Body Corporates - from the catchment.
Key findings were that Indigenous responses to water and irrigation development are interpreted through perceptions of past development, and ongoing environmental and climate change. Indigenous concerns with water development and extraction included consideration of impacts on water quality, on streamflow, and on water-dependent ecosystems and human cultural practices.
Large instream dams were not a favoured form of development, and in general, large-scale water and agricultural development were seen as incompatible with contemporary Indigenous values and lifeways.
Indigenous development objectives were underpinned by goals for ownership and management of traditional lands and by the sustainable retention and/or resettlement of Indigenous people on their country. The majority of business opportunities identified by Indigenous people were small- to medium-scale and land- and natural resource-dependent: pastoralism, conservation services, wild and cultivated bush foods and bush products, ecotourism, agriculture, horticulture, and aquaculture.
Significant returns on investment may be achievable through well-targeted resourcing to local Indigenous entities, particularly Prescribed Body Corporates, to build understanding of business priorities and development objectives, as well as regional coordination processes such as water planning and catchment management.
No. Nor does the Assessment stand as a substitute for formal processes required by cultural heritage, environmental impact assessment or water planning legislation. Nevertheless, the research undertaken for this component of the Assessment identifies key principles, important issues and potential pathways to provide effective guidance for future planning and for formal negotiations with Indigenous groups about their development interests.
No, outside of Indigenous community considerations, no analysis on wider stakeholder values was completed as part of this Assessment. However, scoping analysis completed as part of the Northern Australia Water Resource Assessment indicates that there is a diverse set of stakeholders with different and sometimes conflicting interests and values relating to the use of water resources and irrigated agricultural development.
The diversity of stakeholder perspectives has implications for the ability of developers to gain and maintain social licence to operate throughout the development process. Development planning and implementation is likely to require a systematic and robust social impact analysis.
Were environmental considerations included in this Assessment?
Yes. Though irrigated agriculture in Australia typically occupies a small percentage of a given catchment area, it can potentially use a large proportion of the water. That’s why it was important for the Assessment to consider the impacts of changes in streamflow, resulting from water resource development. We investigated the potential ecological changes to near-shore marine, estuarine, freshwater and riparian ecosystems.
The range of environmental changes that could potentially occur as a result of water and irrigation development is as varied as the number of developments that could be proposed. It was not possible to quantify impacts of development on specific environmental assets, because these cannot be determined in the absence of specific development proposals. This would normally occur as part of an environmental impact assessment.
The Assessment considered a wide range of potential impacts on key water-dependent ecological assets in detail. A range of functional groups and species was identified, as were key habitats and ecosystem processes.
The Assessment is conducted and published independently to policy made by local, state and territory, or federal legislators. CSIRO is Australia’s National Science Agency; it undertakes independent scientific research to help address the nation’s challenges. CSIRO does not develop or recommend changes to policy, nor does CSIRO write, implement, administer or enforce regulation.
The Northern Territory Government is responsible for developing policy and implementing and enforcing regulation in the Northern Territory. The Northern Territory Government places considerable importance on using science and evidence-based approaches to inform the development of its policy.
The Northern Territory Government’s water policy in the Roper catchment was informed in part by scientific studies undertaken as part of the CSIRO Roper River Water Resource Assessment. But it was also informed by other evidence-based approaches, as well as the government’s understanding of values held by the community.
Yes. River catchments vary widely, and CSIRO has developed methods of assessment which can be applied across different catchments. However, it is not possible to make assumptions about resources of catchments based on assessments of catchments found elsewhere.
The Roper River is unique among rivers in northern Australia due to extensive braiding in its mid‑reaches coupled with its large dry-season flows. These baseflows are sourced from groundwater in the regional‑scale Cambrian Limestone Aquifer and the intermediate‑scale Dook Creek formation.
The Roper River has the third‑largest median annual streamflow of any river in the NT, 4341 GL, which is the fifth largest in northern Australia. However, over half the total flow enters the Roper River below Roper Bar, the most upstream point of detectable tidal influence. The median annual discharge at Roper Bar is 1645 GL. The river is unregulated (it has no dams or weirs), and existing licensed surface water extractions are approximately 0.1 GL.
The Assessment undertook a desktop pre-feasibility analysis of potential dam sites in the Roper River catchment. It identified a number of areas, which governments and communities may decide warrant more detailed feasibility studies, to understand the risks of development.
These sites were identified based on a range of factors including geology (what the earth is made of), soils, topography (shape of the land surface), rainfall and water yield (the amount of water that dams could deliver reliably), and location in relation to arable land. The sites identified by CSIRO are not the only ones possible, and we have developed further tools to assess the potential of alternative dam locations and configurations.
The Assessment also provides an estimate of the potential costs of dam construction and the potential value of crops that could be grown under ideal conditions, and outlines risks associated with their development.
CSIRO does not suggest that any dam should be constructed, or make any claims about how such work could, or should, be funded.
Previous studies, such as CSIRO's Northern Australia Sustainable Yields Study (NASY) and Northern Australia Land and Water Science Review (both completed in 2009) were broad-scale desktop studies across all of northern Australia. As a result, they were necessarily less detailed.
The Flinders and Gilbert Agricultural Resource Assessment (FGARA), completed in 2013, focused on two catchments in Queensland (about 155,000 km²).
The Northern Australia Water Resource Assessment (NAWRA), completed in 2018, built on the methods developed as part of FGARA and focused on one study area in each of the three northern jurisdictions (collectively an area of 194,000km²).
The Roper River Water Resource Assessment was built on the methods refined in NAWRA. Although the methods were further refined, the Assessment produced information in a similar format to FGARA and NAWRA so as to better enable direct comparisons between catchments.
Yes. Our research is quality-controlled and peer-reviewed to ensure that its results can be repeated and verified. This Assessment has been peer reviewed by scientists within CSIRO who are not associated with the research, as well as external technical experts within the university, public and private sectors. CSIRO places great importance on the trust placed in the organisation by governments and the Australian community.
This research has been undertaken to improve the knowledge base for decision-making by governments, industries, and communities. Our role is to provide independent scientific advice to inform decision-making by others, and help evaluate the likely outcomes from different policy or management decisions. It is not CSIRO's role to advocate specific policy positions or development decisions.
As the client, the Australian Government’s National Water Grid helped to set the Assessment’s original objectives. This entailed evaluating the opportunities by which water resource development could enable regional economic development and identify and evaluate the risks that may accompany development.
As part of the Assessment, CSIRO worked with the northern jurisdictions, research partners and communities to undertake the evaluations. However, the outcomes of the project reflect the independent views of CSIRO.
No. The Assessment is limited to the geographical confines of the Roper River catchment.
Yes. The Assessment used future climate projections from 32 global climate model simulations, sourced from the Coupled Model Intercomparison Project (CMIP6) website. These projections were used to investigate the impact of long-term changes in rainfall and potential evaporation on runoff and groundwater recharge.
The Assessment also accounted for the fact that rainfall in northern Australia is highly seasonal and has a very high variability from one year to the next. The seasonality and inter-annual variability of rainfall was considered in every analyses undertaken by the Assessment.
Agriculture comprises about 70% of Australia’s water use by sector. Water use by mining, industry, and urban centres trail far behind, by comparison. The non-agricultural users often have a higher capacity to pay for the construction and operation of water infrastructure. Coupled with considerably smaller water demand, water supply options tend to be highly localised.