Scoping land use conversion options for high DIN risk, low-lying sugarcane areas in Burdekin and Mackay Whitsunday regions

Nathan Waltham
Led by: Dr Nathan Waltham, JCU


Project Summary

The Reef 2050 Long-Term Sustainability Plan and Reef 2050 Water Quality Improvement Plan 2017-2022 have set ambitious targets for Great Barrier Reef (GBR) water quality improvement.  Indeed, Water Quality Improvement Plans (WQIP) for most NRMs in the Great Barrier Reef catchments recognise that complete adoption of sugar cane best management practices will still not be sufficient to achieve the nitrogen load reductions required to meet the Great Barrier Reef (GBR) Water Quality Guidelines. Thus additional options need to be considered transitioning agricultural land to other uses is one of those options. Here we capitalise on existing evaluation frameworks developed in NESP TWQ Project 2.1.2, as we aim to (1) identify possible alternate land uses in coastal low-lying cane land, that has a high DIN loss; ii) quantify the economic costs of changing land use, and market mechanisms to incentivise this transition (e.g. Reef Credits); and iii) explore benefits (e.g. farm profitability) of land transition.  Funding this project will better define options land use change across two NRMs that have different climatic conditions, industry groups, water boards and potentially different land use transitions.


Project Publications
Final Report





Project Webinar – 17th November 2020


Project Description

The Scientific Consensus Statement (2017) outlines that complete adoption of sugar cane best management practices would be insufficient to achieve the nitrogen load reductions set out in the Great Barrier Reef (GBR) Water Quality Guidelines and the Reef 2050 targets. Each major NRM organisation along the GBR coast outline in their Water Quality Improvement Plans the need to reduce nutrient (in addition to sediment and pesticide) loads from reaching coastal waters and the Reef.  Other strategies in addition to practice change are therefore required to meet the water quality targets.  Here, working with NRM bodies, community, state government (QWP) and industry partners, we will expand our research program completed previously in the Wet Tropics of mapping low-lying cane land to now include the Burdekin and Mackay/Whitsunday NRM regions.  The extension in our research project in the Wet Tropics has the direct benefit of: (i) identifying potential alternate land uses that deliver lower DIN loads in these two new NRM regions; (ii) quantification of the economic costs and benefits of land use change (in terms of alternate income streams), (iii) identify markets for products and services, and (iv) identify barriers to adoption of alternative land uses to reduce nitrogen focusing on low-lying, low-productivity cane land.  We have previously completed a similar research project in the Wet Tropics catchments (Project 2.1.2) with great impact – those data are now being used by Green Collar, Jaragun Pty Ltd, and Wet Tropics Major Integrated Project (MIPs).  Here we propose to expand the research to encompass land use change options in two further NRM regions, and in doing so expand on the success already generated in the Wet Tropics.

Our recently completed NESP project (Project 2.1.2) has been impactful to the point that emerging private/public funding schemes are using our data to support NRM, government funded schemes (MIPs) and aboriginal corporations to tackle water quality improvement by building constructed water treatment wetlands using private sector generated funding.  For example, our data has been used by Jaragun Pty Ltd in forward planning for new water treatment wetland sites in Babinda, Wet Tropics MIPs trials, and Green Collar are using our data to assist in forward planning of new low-lying cane land conversion to water treatment wetlands funded through the Reef Credits scheme.  In addition, this type of land use change was a ‘solution set’ that was modelled by Alluvium under the Water Science Taskforce, and will soon be re-run and extended to inform prioritisation of water quality investments by governments and non-government organisations going forward.

There is now considerable interest in expanding on the analytical framework, data and knowledge obtained from the Wet Tropics study to additional NRM regions, specifically the Burdekin and the Mackay Whitsunday region.  Expanding the project provides the opportunity to apply the approach in different climatic regions, with different land uses, different land use conversion options, different economic contexts and additional end-user groups/industry bodies.  Funding this project extension would provide more end-user groups, industry, government, and NRM bodies would have access to information for use in decision planning and project site development to assist in achieving water quality targets for the GBR, possibly under proven public/private funding schemes that are now available.

Key objectives

  1. Explicitly identify and map low-lying, low productivity cane areas that pose a high risk of substantial nitrogen (DIN) loss in the Burdekin and Mackay/Whitsunday NRM regions;
  2. Identify possible alternative land uses that could reduce nitrogen loads and potentially provide additional ecosystem service benefits;.
  3. Analyse net economic outcomes from land use conversion, incorporating the costs of conversion (direct costs and foregone income), and potential income streams following conversion (incorporating potential revenues from alternative agricultural outputs, carbon and/or water quality credits, rate rebates etc.).  Where appropriate, additional benefits for farm-level profitability would also be evaluated (e.g. potential re-use of irrigation water from on-farm constructed treatment wetlands).

Key outcomes

  1. Identify low productivity/marginal cane land with a high risk of nitrogen (DIN) loss and alternative land use opportunities;
  2. Define feasible options for converting low productivity/marginal cane land into alternative uses, including indicative at-source cost and benefit estimates that outline water quality improvement and potential ecosystem services benefits;
  3. A range of options for landholders, water boards, industry, NRM, and Government to consider and trial to address GBR water quality issues;
  4. Framework and options for land conversion that could potentially be explored for other GBR catchments and NRM areas.


This project will build on the framework developed in Project 2.1.2 in the Wet Tropics, by firstly identifying constraints and opportunities for innovative, cost-effective options for reducing nitrogen loads through alternative land uses that require no or minimal nitrogen application. There will be a focus on low-productivity / marginal cane land which poses a high risk of nitrogen (DIN) loss through: waterlogging and associated nitrogen losses via the atmosphere, surface water and deep drainage; proximity to receiving waters; and low productivity (and hence low nitrogen use efficiency). This will be particularly interesting in the Burdekin for example, where rising groundwater (in some places salty water) threatens cane production. Therefore the criteria and datasets used in the research will be tailored to each region.

The project will generate GIS maps of marginal, high DIN risk cane land extending our completed work in Wet Tropic catchments. A literature review will identify possible options, based on the success of similar initiatives around the world combined with local research and published information on land suitability, soil constraints and agricultural production systems suited to the region e.g. alternative production opportunities, conversion to wetlands or other natural ecosystems, treatment systems etc. Stakeholders will be engaged to discuss options for cane land based on existing information on geology, agricultural productivity, groundwater levels, saline intrusion etc. An economic assessment of the options will then provide at-source cost/benefit estimates for priority project areas that aim to maximise GBR water quality improvement.

A major strength in this project is that it will quantify potential future income streams such as carbon, water quality credits and (where applicable) rate rebate options as part of this land transition. This will identify new levers for encouraging change such as Reef Credits, carbon offsets or biodiversity credits. Thus alternative uses of low-productivity/marginal, high DIN risk cane land that may be more economically viable and significantly reduce nitrogen loads could generate multiple benefits. Economic analysis is a component of this project, determining whether identified options are economically viable for either the landowner, or public or private investors, and assessing the feasibility of their implementation.

Linkage with other policy, management recovery plans, strategies, and decision making

This project has linkages with:

  • Reef 2050 Long-Term Sustainability Plan – 1) Target EHT3 – There is no net loss of the extent, and a net improvement in the condition, of natural wetlands and riparian vegetation that contribute to Reef resilience and ecosystem health; 2) Target WQT2 – There is no net loss of the extent, and an improvement in the ecological processes and environmental values, of natural wetland; 3) Target WQT4 – Water quality in the Great Barrier Reef has a stable or positive trend.
  • Reef 2050 Water Quality Improvement Plan 2017-2022 – 2025 Water Quality Targets for 60% reduction in anthropogenic end-of-catchment dissolved inorganic nitrogen loads;
  • Wetlands in the Great Barrier Reef Catchments Management Strategy 2016-2021 – Theme 1: Improving wetlands information for decision making and action.;
  • Water quality improvement, system repair, land use management and species conservation needs outlined in the Water Quality Improvement Plan NQ Dry Tropics (2016);
  • Water quality improvement, systems repair, land use management and species conservation needs outlined in the Mackay Whitsunday Water Quality Improvement Plan (WQIP) (2014-2021);
  • Great Barrier Reef Water Science Taskforce (May 2016) – key recommendation Monitoring, modelling, evaluation and reporting for improved decision making and adaptive management;
  • Landscape Resilience – Improving coastal wetland ecosystems through improved understanding of best irrigation management practice in the Lower Burdekin;

Addresses water quality, system repair and coastal ecosystem health concerns raised during recent rounds of “Walking the landscape” facilitated by the Queensland Government’s Queensland Wetlands Program.

Link to other NESP projects

  • NESP Marine Biodiversity Hub (Project B4) – Underpinning the repair and conservation of Australia’s threatened coastal –marine habitats (Completed 2016)
  • NESP Tropical Water Quality Hub (Project 2.2) A tradable permit scheme for cost effective reduction of nitrogen runoff in the sugarcane catchments of the Great Barrier Reef (completed February 2016)
  • NESP Tropical Water Quality Hub (Project 2.1.2) – Framework to transition low-lying cane land to reduce DIN in wet tropic catchments (completed May 2017)
  • NESP Tropical Water Quality Hub (Project 3.1.6) Exploring trading in water quality credits as a cost-effective approach for managing water quality in the Great Barrier Reef (completion January 2019).

NESP Tropical Water Quality Hub (Project 3.3.2) – Science evaluation of coastal wetland systems repair projects across GBR catchments (completion December 2019).


NESP 2017 Research Priority Alignment

Theme 1 – Improved understanding of the impacts, including cumulative impacts, and pressures on priority freshwater, coastal and marine ecosystems and species

This project directly delivers data and knowledge to end users on the impacts of land use and opportunities to transition to alternative use that reduces DIN from reaching local rivers and the reef.  This project includes a large range of end users, that will be involved in project from day one, and will continually assist with generation of data and information.  This NESP project, like our previous projects, will continually promote the results and achievements made by project partners.

Theme 2 – Maximise the resilience of vulnerable species to the impacts of climate change and climate variability by reducing other pressures, including poor water quality

This project will provide data and information to assist end users continually work towards achieving water quality targets imposed in WQIPs.  Achieving water quality improvements will advance government, industry, and community towards resilience of vulnerable species and water quality entering the GBR.  This project has also links to public/private funded investment opportunities such as Reef Credits.

Theme 3 – Natural resource management improvements based on sound understanding of the status and long-term trends of priority species and systems

This is the most relevant research theme to this project.  The large number of project partners proposed here ensures management improvements and changes to land use are administered, and that those decisions are supported by sound understanding of status and long-term trends.  This project aims to provide community, landholders, NRM and industry with additional tools to achieve water quality targets, in addition to identifying funding mechanisms available to supplement and continue farm income.


Project Keywords

Water quality; Cane land; Low-productivity cane land; Nitrogen (DIN); Systems repair; Public/private investment schemes.


Project Funding

This project is jointly funded through JCU, GU, UQ, NQ Dry Tropics, Reef Catchments, Queensland Department – Wetlands Program, Queensland Department– Department of Agriculture and Fisheries and the Australian Government’s National Environmental Science Program.