Tropical Rivers and Coastal Knowledge

What can TRaCK research tell us about the water needs of tropical river ecosystems? Many TRaCK projects generated exciting new information on how tropical ecosystems are structured, including the relative importance of different food sources driving aquatic food webs, patterns of regional biodiversity, hydrological bio-regionalisation and conservation priorities.

TRaCK has created an online resource known as the Northern Environmental Water Tool (NEWT). NEWT brings together all of TRaCK’s research findings about the environmental water requirements of tropical rivers under the ELOHA framework (Ecological Limits of Hydrological Alteration).

For people managing tropical rivers, ELOHA is a useful map of the things that need to be considered throughout the water planning process. Where data or major outcomes from TRaCK research are available, NEWT will provide a more effective and encompassing knowledge base of flow-ecology linkages by making information easily accessible online within relevant steps of the ELOHA process.

Since there is a limited knowledge base available on tropical rivers at the moment and development often outstrips the pace at which thorough scientific assessments can be made, it’s hoped NEWT will give water planners ideas on how to gain a broader understanding of how a river may respond to changes.

Traditional knowledge, like that captured in these Indigenous seasons calendars, can tell us much about the ecology of Australia. The calendars demonstrate the wealth of knowledge that Aboriginal people in Australia hold about the environment.

The groups included:

Gulumoerrgin/Larrakia people from the Darwin region in the Northern Territory

Ngan’gi and MalakMalak people from the Daly River region in the Northern Territory

Kunwinjku people from western Arnhem Land in the Northern Territory

Gooniyandi and Walmajarri people from the Fitzroy River area in the Kimberley region of Western Australia

Kundjeyhmi people from the Ngurrungurrudjba (Yellow Water) region in Kakadu National Park in the Northern Territory

The CSIRO worked with a range of Indigenous language groups to develop a series of calendars. Several of the calendars were developed as part of the Tropical Rivers and Coastal Knowledge program, as well as the National Environmental Resaerch Program’s Northern Australia Hub.

Documenting the calendars has informed the scientific understanding of the relationships between people and the seasonal cycles of resource availability. In the future the calendars may provide an important baseline for detecting ecological change associated with climate change. They have also had a positive social benefit by making Indigenous knowledge more accessible to school students and the broader community.

The Collaborative Water Planning Project aimed to improve community participation in water planning for Australia’s tropical north.

Over the course of fifteen months from 2008-9, the project trialled, promoted and evaluated two planning tools: a stakeholder analysis and a participatory groundwater visualisation tool (3D model).

The team worked closely with representatives from local stakeholder groups, members of the broader community and staff from the Water Resource Management Branch of the Department of Natural Resources, Environment, the Arts and Sport (NRETAS) and independent experts from the Queensland University of Technology.

The Howard East bore field in the Northern Territory relies on groundwater supplies to satisfy rural and urban residential, horticultural and commercial needs. A regional water plan for the area is now in development but in the absence of more information, the 3D model was designed to ensure the Howard East Aquifer is managed sustainably for future generations.

The model relies on the best available data to help people understand ground water systems and answer the following questions:

  • How does the Howard East Aquifer work?
  • What effect does the current rate of pumping have on local ground water levels?
  • Is the aquifer taking longer to recharge during the wet season?
  • Can you see the effects of pumping on the surface water bodies (e.g. Howard Springs, Girraween and McMinns Lagoon)?
  • Are older shallower bores likely to run dry in the future?

The model provides a detailed cross section of the Howard East Aquifer at specific points of interest. By selecting these areas, users can see the topography, soil type, surface and natural drainage features of the system, and watch short animations that illustrate the changes in aquifer levels over time and season.

For more information about the project, read the summary report.

Other reports that relate to this research include:

Rural Darwin (NT) Case: Analysis of Stakeholder Interests in the Ground Water Resources of the Howard East Aquifer

Water planning poster

Howard East information sheet

River health is in generally good condition in the wet-dry tropics compared to the more developed parts of Australia. However river health is modified by anthropogenic activities such as grazing, feral animals, fire, mining and agriculture. A survey conducted by TRaCK researchers showed that northern Australian residents expect that tropical rivers will reamin healthy, and view any degradation, even if minor on a national scale, as being significant and the possible start of long-term degradation.

Monitoring river health in northern Australia is challenging. The vast area, small population base, high seasonality of rainfall, and limited all-weather road infrastructure pose resource and logistical constraints. In the wet season most rivers are inaccessible. In the dry season many rivers cease flowing while others reduce to a series of disconnected pools or waterholes. Some rivers and streams are groundwater-fed and flow year-round.

As part of its synthesis and adoption year, TRaCK researcher Dr Simon Townsend – with affiliations to Charles Darwin University and the Northern Territory Government – led the development of a report which combines the knowledge of leading scientists on monitoring river health in the wet-dry tropics. Co-authors of the report included TRaCK researchers from Griffith University, the University of Western Australia, CSIRO and the North Australian Indigenous Land and Sea Management Alliance, and scientists from the Australian Government, Queensland and Western Australian environment and water departments.

The scientists identified early detection of anthropogenic effects as the key objective for long-term monitoring. This approach is especially significant in the wet-dry tropics to provide warning of river health degradation so as to avoid the social and economic costs of restoration.

Download or view the report, or watch a short video about monitoring river health.

TRaCK has developed scientific knowledge in a range of areas including ecology, socio-economy, and river hydrology in the wet-dry tropics of northern Australia.

We live in a world where many processes are highly connected. To plan and manage our natural resources effectively we need to take those connections into account by integrating the knowledge developed by different scientific disciplines such as economics, ecology, and hydrology and applying the knowledge to management decisions. For instance, we may want to look at how water allocation plans may affect fish habitats and our economy.

TRaCK has adapted a framework known as Management Strategy Evaluation (MSE) to help resource managers analyse various management options, and clearly view the trade-offs.

The MSE:

  • Integrates the knowledge developed by various scientific disciplines and that of resource management agencies.
  • Is explicit about uncertainties in resource management, such as the inter-annual variability of rain, and actively support the adaptive management approach to better deal with these.
  • Provides the functionality to define and evaluate a broad range of management options and to examine the results in a rigorous and consistent way.

How is it being used?

Government resource planners and managers have the difficult task of conserving and managing water resources in a transparent, equitable and sustainable manner. This is carried out through the development of water allocation plans and water management activities, collection of information through monitoring, and assessments of the condition of the jurisdiction’s water resources.

Throughout 2011-12, the project team refined the MSE models and software to evaluate management strategies for the Daly River catchment, in close collaboration with Northern Territory Government water managers. The Daly River MSE is now capable of evaluating a range of complex scenarios, and during the synthesis year was used to support evidence-based decision-making in water-related resource management. The fact that the model can save scenarios as evidence of rationale at the time decisions are made is seen as a major benefit.

The water planners assessed the MSE software’s practical use and concluded that the model would be a useful tool to inform internal and external stakeholders, support integrated outcomes and assist the government in making planning and licence decisions in the Daly River Catchment. The water planners intended to use the MSE in the review of water allocation plans for the Tindall and Oolloo aquifers.

Statutory water rights for Australia’s Traditional Owners and Indigenous communities remain one of the major unrealised promises of the national water reform process.

While some legal and policy provisions for Indigenous water reserves have been created, the gap between these ‘hypothetical’ entitlements and the use of water resources for self-determined economic development opportunities persists.

TRaCK and other agencies including the National Water Commission have attributed this to a range of factors, including a low awareness of water planning processes and water reform generally among Indigenous people. Likewise, agency water planners have found difficulties in undertaking effective Indigenous engagement that contributes directly to statutory water plans.

Drawing from previous TRaCK research, the experiences of the Indigenous Water Facilitator Network and the wide-ranging work done on Indigenous interests in water planning, a field guide has been developed to help Indigenous communities better understand and participate in water planning, and to aid planners in facilitating Indigenous involvement.

The field guide provides a single entry point to the information available and describes what water planning is, how Indigenous people can get engaged and what they need to bring to the table to participate effectively. A series of powerpoint modules for people giving presentations are also available in pdf format.

1.1 What is water reform
1.2 Understanding Australia’s tropical rivers
1.3 How are governments involved in water reform
1.4 The laws and policies of water reform
1.5 How are scientists involved in water reform
2.1 What is water planning
2.2 Key terms in water planning
2.3 The water planning cycle
2.4 Science in water planning
2.5 Including community views in planning
3.1 Indigenous engagement and participation
3.2 What Indigenous groups say about water reform
3.3 Principles for good Indigenous engagement
3.4 Water rights and Strategic Indigenous Reserves
3.5 How have other groups been involved in water planning

The guide is available for download, along with the Indigenous water planning and engagement overview.

Australia’s tropical rivers hold special significance for Indigenous communities. Indigenous people value rivers in a number of interrelated ways; rivers provide food and medicines; they are part of a culturally significant landscape; and have the potential to sustain future water-related businesses and employment.

TRaCK researchers set out to understand when and where Indigenous people were harvesting aquatic resources like fish, turtles and lotus lilies, and the contribution these resources make to their diets and household incomes.

In the Daly River region in the Northern Territory, the project team worked with the communities of Kybrook Farm and Pine Creek and Nauiyu Nambiyu (Daly River). In the Fitzroy Valley of the Kimberley in Western Australia, residents from the communities of Bayulu, Bungardi, Darlgunya, Junjuwa, Ngurtuwarta, Muludja and Noonkanbah were involved.

Maps of the spatial distribution of resource use were created to help understand which habitats were most commonly used and how river flows might affect those habitats. Household surveys were undertaken to work out how often and where people were hunting or fishing, and whether they used the resources themselves or shared them around. Finally, the project team conducted a range of activities to reveal the social and cultural value of river systems with the goal of better understanding what the effects of water-use changes would be.

The research showed that many Indigenous people regularly hunt and fish and that catches are widely shared or traded with others. When the cost of buying these aquatic resources in the shop was calculated, it was found that aquatic resources make a substantial contribution to household incomes in regions where average incomes are very low. Furthermore these resources are an essential part of daily social and cultural life – access to wild species, and the aquatic habitats that support them, is critical to maintaining a vibrant customary economy.

Research from other TRaCK projects has shown that many of the species that are important for customary harvest, like long-necked turtles, black bream, barramundi and mullet are also the species at high risk from reduced river flows.

Read more in the project’s summary report.

Gully erosion into active river floodplains and terraces (relict floodplains) affects river health and aquatic life, industries, infrastructure and Indigenous cultural activities. As they erode wider and deeper, gullies can make the land unusable for pastoral and agricultural use.

They also carry sediment and nutrients from the floodplains into rivers, creeks, lagoons, estuaries and oceans, affecting aquatic life and their habitat. In northern Australia, gully erosion rates have increased up to ten times since European settlement, due to cattle grazing and land use change (fire/weeds/roads/fences) along river frontages.

TRaCK researchers Jeff Shellberg, Andrew Brooks, and John Spencer from Griffith University have studied the causes and impacts of gully erosion into alluvial soils, which is widespread across northern Australia, and recommend major changes to land management along river corridors.

Options for rehabilitating and protecting affected land are outlined in a summary and associated report.

Key findings:

Alluvial gully erosion represents a major threat to riparian and aquatic landscapes and agricultural production in northern Australia.

European land use practices have accelerated the initiation and growth of alluvial gullies, with up to ten times greater erosion rates since European settlement.

Sediment yields from gullies on floodplains in northern Australia are very high by both Australian and world standards (up to 350 tonnes per hectare per year).

Gully erosion from floodplain soils is a major source of sediment in northern Australian catchments.

Once started, gully erosion will continue to increase at current rates unless changes to land management paradigms are made, along with significant rehabilitation efforts.

Promoting native grass vegetation and limiting soil surface disturbance are the most important defences against alluvial gully erosion.

Changes to cattle grazing practices, such as fencing cattle away from steep river banks and riparian zones along large rivers, can prevent alluvial gully formation and reduce erosion rates.

Changes to road and fence locations and maintenance practices can reduce the triggering of alluvial gullies.

In areas of strategic and cultural importance, rehabilitation tools have been developed to determine the best passive or direct biological, chemical, and physical methods for reducing erosion once it has begun.

Social, economic, and political issues present major challenges to effectively rehabilitating gully-prone landscapes.

For more information on Gully Rehabilitation and Grazing Land Management, visit the Cape York Water Quality website, or access the following scientific publications by clicking on the links below:

The hydrogeomorphic influences on alluvial gully erosion along the Mitchell River fluvial megafan, northern Australia

Sediment production and yield from an alluvial gully in northern Queensland, Australia

Alluvial gully erosion rates and processes across the Mitchell River fluvial megafan in northern Queensland, Australia

Land-use change from indigenous management to cattle grazing initiates the gullying of alluvial soils in northern Australia

Alluvial gully erosion: an example from the Mitchell fluvial megafan, Queensland, Australia