Authors: Mihir Gupta, Tim Westwood, Peter Legg and Neal Hughes
ABARES has worked with colleagues in the Australian Bureau of Statistics (ABS), Bureau of Meteorology (BOM), Murray-Darling Basin Authority (MDBA) and each of the state water agencies to compile a unique and comprehensive dataset detailing water availability, market outcomes, irrigation activity, climatic conditions and commodity prices for a consistent set of catchment regions in the Murray-Darling Basin (MDB).
The MDB water market dataset includes a Water Supply file and a Irrigation Activity file. To supplement the datasets, metadata that describes each variable, sources and other salient information is also provided. This report provides a brief summary of the scope and coverage, and the methods used to construct the data.
ABARES is continually improving the quality and scope of the MDB water market dataset. While extensive care has been exercised in preparing this dataset, it remains subject to further refinement in the future, particularly where data has been estimated or imputed.
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Scope and Coverage
The MDB water market dataset covers the period of July 2000 to June 2020, and includes catchment regions across Australia, focussed particularly on the MDB. The MDB is split into northern (nMDB) and southern (sMDB) (Figure 1 ). The nMDB covers QLD and northern NSW, while the sMDB covers southern NSW, ACT, Victoria and South Australia.
The list of regions in the Basin is outlined in Table 1, as well as if they are included in the Water Supply or Irrigation Activity datasets. In preparing the data, ABARES focussed on providing consistent time series data for key catchments and irrigation activities in the basin. However, this was not possible for all regions due to data limitations and gaps in coverage. Water Supply data has been collected for all MDB regions in NSW, Vic. and SA, but was not collected for QLD regions. Irrigation Activity data has been compiled for all catchments in Australia, but consistent time series are primarily available for catchments within the basin.
|NSW Border Rivers||nMDB||Demand, Supply|
|QLD Border Rivers||nMDB||Demand|
|Australian Capital Territory||sMDB||Demand|
|Lower Darling||sMDB||Demand, Supply|
|NSW Murray Above (Above Barmah Choke)||sMDB||Demand, Supply|
|NSW Murray Below (Below Barmah Choke)||sMDB||Demand, Supply|
|Adelaide and Mount Lofty||sMDB||Demand|
|South Australian Murray||sMDB||Demand, Supply|
|VIC Murray Above (Above Barmah Choke)||sMDB||Demand, Supply|
|VIC Murray Below (Below Barmah Choke)||sMDB||Demand, Supply|
The MDB water market dataset offers a number of improvements over previous datasets released by ABARES. For example, the Water supply file includes additional variables, such as forfeited water (split by during year, and end of year), which allows for more accurate estimations of total water supply. To our knowledge, the Irrigation Activity file is the first comprehensive catchment level dataset for water use, area irrigated and production, and is the result of close collaboration with the ABS.
The construction of the MDB water market dataset involved considerable effort, given the large number of data sources and various inconsistencies between them. A number of data imputations, assumptions and regression estimations were required, in addition to filling gaps through external data sources in order to generate time series data for a consistent set of regional and industry definitions.
The final datasets draws from various sources, which are further detailed in the metadata spreadsheets accompanying this product.
The Irrigation Activity file contains data for each of the variables listed in Table 2 for financial years from 2005–06 to 2018–19. ABARES has worked extensively with the ABS to create a custom catchment level dataset of irrigation activity. This dataset has been built from unit-record data collected through various agricultural censuses and surveys, and provides irrigation activity data for catchment regions across Australia from 2010–11 onwards. For the period 2005–06 to 2010–11, ABARES apportioned Natural Resource Management (NRM) level public data to catchment regions, using methods previously described in Gupta et al. 2018. The apportioning method was calibrated using data provided by the ABS for 2010–11 to 2012–13.
|Area watered||Area of irrigation by region and industry||Ha|
|Volume applied||Volume of irrigated water applied total||ML|
|Production||Volume of irrigated production. For commodities Almonds, Cotton, Rice and Grapevines production is recorded as kg. For all other commodities production is reported as an index value||kg|
|Commodity price||Nominal commodity prices. For commodities Almonds, Cotton, Rice and Grapevines prices are recorded as $/kg. For all other commodities prices are reported as an index value||$|
|GVIAP||Nominal dollar value of irrigated agricultural production||$|
|Area_br||Area of bearing grapevines||Ha|
|Area_nbr||Area of non-bearing grapevines||Ha|
|Tree_br||Number of bearing almond trees||No.|
|Tree_nbr||Number of non-bearing almond trees||No.|
|K_Almonds||The total number of bearing trees as a proportion of total almond trees||%|
|L_meta||Metadata for Area_watered||Value|
|W_meta||Metadata for Volume_applied||Value|
|Q_meta||Metadata for Production||Value|
|K_meta||Metadata for K_Almonds||Value|
|Y_meta||Metadata for Commodity_price||Value|
Table 3 lists the irrigation activities considered in the demand file. Irrigation activities are based on ABS industry classifications. A significant feature of the MDB water market dataset is that it separately reports data for the almonds industry, which is elsewhere part of the combined fruit and nut category reported by the ABS.
|Almonds||Pasture for hay|
|Pastures for grazing||Vegetables|
For regions within the MDB, where data was missing (for example, due to ABS confidentiality constraints) ABARES has estimated values. ABARES has used a variety of methods to impute missing data, as listed in Table 4. All imputed data points are marked in additional columns in the dataset (denoted with the "meta" suffix) and remain subject to further refinement.
|1||ABS unit-level data constructed and cleared by ABARES.|
|2||Catchment data approximated by ABARES using ABS NRM level data for 2006 to 2010.|
|3||Missing values filled with a linear interpolation|
|4||Missing values filled with ABARES regression results|
|5||Data obtained from external sources|
|6||Missing data that was not filled using other methods|
The Water Supply file was compiled using data from the MDBA, state water agencies (NSW Department of Planning, Industry and Environment, Goulburn-Murray Water, Northern Victorian Resource Manager and the South Australian Department for Environment and Water), BOM and the Department of Agriculture, Water and the Environment (DAWE). Water price data has been compiled and cleaned by ABARES using the GAM price cleaning method described in Sanders et al. 2019.
Each of the variables included in the Water Supply file are briefly described in Table 5, which contains data for catchments in the MDB from 2000–01 to 2019–20.
|Entitlement volumes||Water entitlements are an ongoing right to access a share of water. They are equal to a nominal volume of water for different types of reliability, and are able to be traded or held for potential use.||ML||State water availability reports|
|Allocation percentages||The percentage for each entitlement type that is able to be accessed during a water year or a particular period.
For combined regions (i.e. Vic. Goulburn-Broken) allocation percentages are derived by calculating the combined regional allocation volume, divided by the combined regional entitlement volume.
|%||State water allocation announcements|
|Uncontrolled flow usage||Uncontrolled flow events occur when there is a water flow that is not able to be controlled, and is greater than the amount allocated for consumption or environmental needs. During this time anyone is allowed to access the water. The volume accessed for use is considered the uncontrolled flow usage.||ML||New South Wales Available Water Determination (‘AWD’) Reports|
|Allocation volume||A water allocation is the right to access a volume of water during a water year. It is equal to the entitlement volume multiplied by allocation percentages for each entitlement type.||ML||State water allocation announcements, state water availability reports, NSW AWD reports|
|Within year forfeits||Water users can sometimes lose water from evaporation or other causes. When this occurs the volume lost is considered a within year forfeit.||ML||Victorian unused water reports, NSW General Purpose accounting and AWD reports|
|End of year forfeits||End of year forfeits are equal to the total volume of water that has not been used in the water year or carried over into the next year.||ML||VIC Unused water reports, NSW General Purpose accounting, and AWD reports|
|Carryover from previous year||The total volume of allocation water individual water right holders have held in storage to carry over from the previous year.||ML||NSW Department of Primary Industries, Northern VIC Resource Manager, South Australia Department for Environment and Water, Vic. Water Register|
|Environmental buyback entitlement volumes||Total volume of entitlements purchased for the environment by the Commonwealth Environmental Water Holder (CEWH).||ML||DAWE|
|On-Farm Infrastructure programs entitlement volumes||Total volume of entitlements recovered for the environment through on-farm infrastructure programs.||ML||DAWE|
|Off-Farm Infrastructure program entitlement volumes||Total volume of entitlements recovered for the environment through off-farm infrastructure programs.||ML||DAWE|
|Delta||The sum of entitlement volumes recovered for the environment from buybacks and on-farm infrastructure programs as a proportion of the total volume of entitlements.||%||ABARES estimate|
|Price of water allocations||Average annual real (2018–19$) allocation price.||$/ML||BOM national water register. Data was cleaned using ABARES price cleaning scripts.|
|Net allocation water trade from CEWH to irrigators||Total volume of water sold from the CEWH to irrigators.||CEWH|
|Net allocation water trade (excluding environmental trade)||Total volume of allocation water traded into a catchment region subtracted by the total volume of water traded out of it.||ML||MDBA provisions, Victorian Water Register|
|Water Use||Calculated field estimating total water use by catchment by year||ML||ABARES estimate|