10 December, 2025
Industries
Client
Sunwater
Disciplines
After a sustained period of strong performance, the last five years in the Nogoa Mackenzie WSS has been characterised by relatively poor availability of Medium Priority water entitlements for agricultural users. Compounded by the removal of the inflatable bag from Bedford Weir, this period of poor reliability has coincided with strong performance in most other water supply schemes throughout Queensland.
This has significantly impacted irrigation users in the scheme, which includes largescale cotton producers and high-value horticulture producers, including mandarins and table grapes, which target high-value niches in the export and domestic markets respectively. To address grower concerns regarding the decline in performance of the MP entitlements, Sunwater undertook a project to assess the feasibility of a range of infrastructure options for improving water security in the scheme, including the augmentation of existing infrastructure and construction of new water storages.
Synergies was engaged to undertake the water demand assessment and economic analysis of shortlisted options. This involved the development of a probabilistic water demand model, informed by extensive consultation with stakeholders in the agricultural, industrial, and urban water sectors. The model underpinned the cost-benefit analysis of the shortlisted options, which was undertaken in accordance with the Queensland Government’s Business Case Development Framework and was subject to formal Gateway Review processes.
Sunwater obtained government funding to undertake an Options Analysis for improving water security in the Nogoa Mackenzie WSS, following several years of low water availability. Synergies was engaged to undertake two components of the OA – the water demand assessment as part of the Service Need Assessment and the economic analysis of the shortlisted options.
The water demand profile in the Nogoa Mackenzie WSS is characterised by a range of agricultural and industrial demands, in addition to urban water demand for Emerald and other Central Highlands townships. The agricultural demands in cotton and other broadacre production (grains and pulses), citrus production (predominantly mandarins targeting high-value export markets), and other perennial horticulture, including table grapes for the early season market, and macadamias. The key industrial demand is for coal mining in the Southern Bowen Basin.
The demand drivers across the base of water entitlement holders differs across demands, including domestic market trends, long-term trajectories for key Asian export markets, to the long-term outlook for the global seaborne thermal and metallurgical coal market.
The water demand assessment required the development of a model that reflected the range of demand drivers and accommodated the considerable uncertainty that exists in relation to these factors over the 30-year evaluation period. A robust demand assessment is critical not only to define the service need for the OA, but also to underpin the shortlisting of project options and the economic and financial analysis of the shortlisted options in the OA.
A probabilistic water demand model was developed incorporating all agricultural and industrial water demands in the Nogoa Mackenzie WSS. Synergies undertook extensive desktop and market analysis, which was supplemented by consultation with stakeholders across all demand segments in the scheme (cotton, citrus, table grapes, coal mining). The analysis and consultation informed firstly, the identification of key drivers for each demand segment, and secondly, the setting of appropriate parameter values in developing the model.
Most likely, low, and high estimates were identified for each demand driver, which were combined to develop the probabilistic model. The model provides demand profiles – most likely, P10, and P90 – for aggregate water demand and for individual demand segments. This not only provides a robust picture of the central or most likely demand but, using Monte Carlo simulation, provides a comprehensive picture of the potential range of future water demand profiles, reflecting the uncertainty that exists in relation to the key demand drivers.
Infrastructure options were then shortlisted having regard to the outcomes from the demand assessment and other preliminary information.
The shortlisted options were then subject to an assessment of economic feasibility, under the cost-benefit analysis approach. Synergies undertook the economic analysis, with the benefit quantification informed by scheme-specific, farm-level financial models for key crops in the scheme. These models were developed with direct input from irrigators in the scheme to ensure the quantification of accurate economic benefits. A comprehensive economic analysis report was developed, and chapter inputs were drafted for the OA. Synergies also assisted with price modelling to inform the financial analysis of the options.
Our comprehensive and robust assessment of long-term water demand in the Nogoa Mackenzie WSS provided Sunwater with a robust basis for undertaking comparative assessments of the long list of infrastructure options, in addition to ensuring the robust quantification of economic benefits for the shortlisted options. The demand modelling and economic analysis was provided a positive appraisal by the Gateway Review Panel.
In addition to ensuring the completion of a robust Options Analysis for the Nogoa Mackenzie WSS, the probabilistic demand assessment also provides Sunwater with valuable information regarding the long-term outlook for several of its key customer bases in Central Queensland. The approach to developing the model enables the key parameters to be updated over time, providing Sunwater with a key resource to inform infrastructure planning in Central Queensland over the long term.
To find out more about this project and how Synergies can assist you, send an email to: contactus@synergies.com.au