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Abstract: Regional-scale ecological restoration priorities such as increasing the extent and quality of native vegetation are generally planned at catchment scales, while on-ground restoration actions are generally implemented at paddock or farm scales. This paper describes the use of spatial multi-criteria assessment methodologies to construct maps of regional conservation priorities and assesses how these maps map influence farm-scale actions in Western Victoria, Australia (e.g. farm-scale revegetation for salinity, wind erosion, stock shelter, etc). The study also incorporates agricultural production in the decision analysis through the use of historical yield mapping data obtained from harvest logs from precision agriculture equipment. Via a stakeholder workshop, farmer land use priorities were elicited with and without access to maps of regional conservation priorities. Results highlight that production imperatives drive farmer-led conservation actions and that regional conservation priorities have only limited impact on actions. The paper also identifies limitations of applying MCA methods across multiple decision-making scales such as the need to generalise priorities where domain knowledge is relatively high, and the challenges associated with MCA criteria definition. [ABSTRACT FROM AUTHOR]

Abstract: Temporary water trading is an established and growing phenomenon in the Australian irrigation sector. However, decision support and planning tools that incorporate economic and biophysical factors associated with temporary water trading are lacking. In this paper the integration of an economic trading model with a hydrologic water allocation model is discussed. The integrated model is used to estimate the impacts of temporary water trading and physical water transfers. The model can incorporate economic and biophysical drivers of water trading. The economic model incorporates the key trade drivers of commodity prices, seasonal water allocations and irrigation deliveries. The hydrologic model is based on the Resource Allocation Model (REALM) framework, which facilitates hydrologic network simulation modelling. It incorporates water delivery system properties and operating rules for the main irrigation and urban centres in a study area. The proposed integration method has been applied to a case study area in northern Victoria, Australia. Simulations were conducted for wet and dry spells, a range of commodity prices and different irrigation distribution system configurations. Some example analyses of scenarios incorporating water trading were undertaken. From these analyses potential bottlenecks to trade that constrain the economic benefits from temporary water trading were identified. Furthermore, it was found that in certain areas of the system, trading can make impacts of long drought spells worse for water users, e.g. irrigators. Thus, the integrated model can be used to quantify short-term and long-term third party impacts arising from temporary water trading. These findings also highlight the need to link “paper trades” (estimated by economic models) to physical water transfers (estimated by biophysical models). [Copyright &y& Elsevier]

Summary: Melbourne is facing a severe drought having its 12th consecutive below average rainfall year. Water authorities have been forced to impose rigorous water restrictions including voluntary per capita water use targets after more than 20years of unrestricted water supply. The current severe drought and dwindling water resources have accelerated the use of alternative water sources including domestic rainwater. There is a large variation in average annual rainfall in the Greater Melbourne area ranging from 1050mm in the east to 450mm in the west. Hence, there is a significant difference in the tank size required in the west and the east of Melbourne to meet a similar demand and to provide the same supply reliability. The paper presents a novel methodology and a relationship for optimal sizing of rainwater tanks considering the annual rainfall at the geographic location, the demand for rainwater, the roof area (catchment area) and the desired supply reliability. The characteristic of the developed dimensionless curve reflects these variables and paves the way for developing a web based interactive tool for selecting the optimum rainwater tank size. [Copyright &y& Elsevier]

Abstract: We discuss the role and characteristics of water markets in Australia in facilitating efficient water allocation. Administrative, regulatory and/or political barriers to effective functioning of water markets are reviewed with a focus on the southern Murray-Darling Basin (MDB) region of Australia. A mathematical model is developed to estimate the costs of existing restrictions and the benefits from potential changes in water markets (e.g., removing barriers in temporary water markets). The modelling results reveal that expanding trade leads to an increase in mean annual net returns from AU $2502 million to AU $2590 million (i.e., an increase of AU $88 million). When the current volume restrictions, exchange rates, and trading charges are accounted for, mean annual net returns reduced from AU $2590 million to AU $2573 million (i.e., a reduction of AU $17 million). The exclusion of any of the three southern MDB states from the interstate water trading imposes significant costs. If South Australia, New South Wales or Victoria withdraws from the water market, net returns are reduced by AU $27 million, AU $31 million and $63 million, respectively. The paper outlines the policy implications of strategies to remove market barriers and to facilitate efficient and effective water trading. [Copyright &y& Elsevier]