Integrated Water Accounts for the Canberra region methodology

1 These Explanatory Notes focus on the methods used for the sections of the accounts prepared according to the System of Environmental-Economic Accounts (SEEA) framework. Please follow this link http://www.bom.gov.au/water/nwa/2018/canberra-integrated-pilot/supportinginformation/methods.shtml to the Bureau of Meteorology methods section, describing the methods used for the sections of the accounts prepared according to the Australian Water Accounting Standard.

2 The Australian Bureau of Statistics (ABS) and the Bureau of Meteorology produce annual national water accounts of different types, for differing but complementary purposes, using two distinct frameworks. A collaboration between these two government organisations has produced an integrated set of water accounts for the Canberra region, providing an example of two key government organisations working together to produce a valuable set of environmental-economic accounts.

3 As a result of the collaboration, a joint ABS/Bureau of Meteorology publication has been produced, presenting water accounts using the Australian Water Accounting Standards (AWAS 1) framework, including water accounting statements and contextual analysis, as well as four sets of integrated water accounts compiled using the System of Environmental-Economic Accounting (SEEA), for the reference period 2013-14 to 2016-17, including accounts for:

• water assets;
• physical supply and use of water;
• monetary supply and use of water; and
• water condition/quality.
   

4 The ABS contribution to this publication is based on extending the concepts in its annual publication Water Account, Australia (WAA) (cat. no 4610.0), one of the environmental-economic accounts produced by the ABS that is compiled, as far as possible, in accordance with the SEEA framework. The WAA consists of supply and use tables (collectively referred to as flow tables) for both physical and monetary volumes. This joint publication extends the scope of the WAA to include SEEA-based asset and water quality accounts for water resources.

5 The SEEA was first published by the United Nations in 1993 and was elevated to an international statistical standard in 2012. Environmental-economic accounts extend the boundaries of the System of National Accounts (SNA) framework to include environmental resources which occur outside of the economic production and asset boundaries measured by the SNA.

6 The Bureau of Meteorology contribution to this publication, which includes water accounting statements and contextual analysis, is based on the National Water Account (NWA), compiled under the Australian Water Accounting Standards (AWAS 1) framework.

7 The AWAS 1 is based on financial accounting principles. They guide the preparation and presentation of the Bureau of Meteorology’s NWA, which is designed to inform users about how water has been sourced, managed, shared and utilised. The National Water Account also enhances public and investor confidence in the amount of water available, allocated, traded, abstracted for consumptive use and recovered and managed for environmental and other public benefit outcomes (Bureau of Meteorology, 2014).

8 The geographic boundary in scope for this publication includes the Australian Capital Territory (ACT) and the surrounding catchment region; it includes the Cotter Catchment, Molonglo Catchment, Gudgenby Catchment, the Queanbeyan Catchment and part of the Murrumbidgee Catchment (see Figure below).

9 Water asset accounts present information, in physical units (e.g. ML), on the stocks (assets) of water resources at the beginning and end of an accounting period, and present various water resource types as well as origins and destinations of water inflows (e.g. from rainfall and upstream sources) and outflows (e.g. abstractions and evaporation). They link information on abstraction and returns with information on the stocks of water resources (SEEA Water).

10 The ABS has not published water asset account tables as a component of its WAA in the past. The Bureau of Meteorology’s NWA presents the water asset account in a different format to the SEEA framework, presenting a water balance for surface water storage, groundwater storage and the urban water system separately for the Canberra region. This collaborative project provided the opportunity for the ABS to work closely with the Bureau of Meteorology to develop a set of SEEA-based asset accounts for the Canberra region.

11 Water resources that are in scope for the SEEA asset account includes water in freshwater systems, such as from surface water and groundwater. Also included are information on water held in the urban system. The urban water system includes (a) potable and non-potable water supply, including pipes in the delivery infrastructure, 47 urban service reservoirs, tanks and off-stream ponds; (b) wastewater collection, including wastewater lagoons and ponds, pipes, tanks, pits, sumps and storages; and (c) recycled water supply, including pipes, tanks and storage reservoirs. The inclusion of the urban water system in the water asset accounts is an extension of the recommendations of the SEEA Water framework, but was made possible in the Canberra region due to available data. The amount of water stored in the urban water system is relatively small at any given point in time; however, relatively large volumes of water flow through the system.

12 The water asset accounts cover the following water resources:

• Surface water (large artificial reservoirs/dams, lakes and rivers);
• Groundwater; and
• The urban water system.
   

13 Data on stocks of groundwater for the Canberra region were not available, however estimates of some of the inflows to (e.g. leakage from pipes) and outflows from (e.g. extraction through household bores) the groundwater system are presented in this publication.

14 The following data were also not available for the asset accounts presented in the publication:

• stocks of water held in farm dams;
• stocks of water held in rainwater tanks; and
• stocks of soil water.
   

15 In the asset account tables, the 'increases in stocks’ include:

• Returns from the economy: the total volume of water that is returned from the economy into surface and groundwater systems;
• Precipitation: the volume of rainfall that directly falls on to water resources;
• Flood return: the return flow from a floodplain back into a river;
• Runoff: the volume of water from precipitation that flows over the land surface and into surface water bodies, including major reservoirs, lakes and rivers (note that flows into farm dams are outside the scope of this publication);
• Inflows from upstream territories: river inflows (i.e. via the Murrumbidgee River) into the Canberra region; and
• Inflows from other resources in the territory: inflows from one resource to another within the region (e.g. from a river into a major reservoir).
   

16 The ‘decreases in stocks’ include:

• Abstraction/diversions: the volume of water sourced from water resources to be used in the economy;
• Evaporation: the amount of water evaporated from bodies of water throughout the reference period;
• Overbank flow: waterway floods out of a main channel that spill out onto a floodplain;
• Outflows to downstream territories: river outflows (i.e. via the Murrumbidgee River) from the Canberra region to downstream territories;
• Outflows from other resources in the territory: outflows from one resource to another within the region (e.g. from a major reservoir to a river); and
• Other changes in volume: changes in water volume that are not classified or recorded elsewhere in the account, including unaccounted for losses.
   

17 The Murrumbidgee River, which drains the entire Canberra region, is the source of ‘inflows from upstream territories’ and the destination for ‘outflows to downstream territories’ for the Canberra region. The river is one of Australia’s major rivers and is the second longest river in the country. It flows for 66km through the ACT, picking up the important tributaries of the Gudgenby, Queanbeyan, Molonglo and Cotter Rivers, entering the ACT on its eastern border and exiting on the north-western border.

18 The Bureau of Meteorology was the primary source of data for the water asset account. Data from the Bureau of Meteorology’s NWA provided estimates on water abstractions/diversions and updated estimates on dam, lake and river stocks.

19 Runoff, flood returns, precipitation, overbank flow and evaporation estimates were obtained from modelled estimates produced by the Bureau of Meteorology.

20 The ACT Government’s Environment, Planning and Sustainable Development Directorate (EPSD) provided data for groundwater and self-sourced water (i.e. water sourced by industries other than the water supply industry) use in the ACT.

21 River, dam and lake inflow and outflow estimates from both within the region and from external territories were sourced from gauge data, where available. The following gauge stations were used:

22 All self-sourced water (i.e. water sourced by industries other than the water supply industry) was allocated as abstractions from the river system.

23 Outflows from Corin Dam were also recorded as inflows into Bendora Dam, using Station_no 410752 - 'Cotter River below Corin Dam'.

24 Some runoff was allocated directly to dams and lakes, with the remainder allocated to rivers, ensuring that all modelled runoff in the Canberra region was accounted for.

25 Outflows from the urban water system into other resources in the territory included water delivered to customers, treated wastewater discharge and leakage from pipes (to groundwater).

26 Total abstractions/diversions from major reservoirs were used to estimate inflows to the urban water system from other resources in the territory. Generally, most of the water required to meet Canberra and Queanbeyan’s requirements is drawn from the Bendora Dam with water from Googong Dam being drawn during times of high demand during summer or extensive dry periods. In periods of low water supply, additional water can be drawn from the Murrumbidgee River.

27 The physical water supply and use tables describe water flows in physical units (ML) within the economy. These accounts describe the initial abstraction of water from the environment by the economy (i.e. by water utilities and other water users) and its supply and use within the economy, to its final discharge back to the environment (e.g. as treated wastewater by the sewerage industry). Physical supply and use tables follow the same general structure as the supply and use tables presented in the System of National Accounts (SNA).

28 There are several points of intersection between the water asset and physical supply and use accounts:

• the volume of water abstracted from the environment (surface water and groundwater) by the economy;
• wastewater collected (usually by the water supply industry); and
• return flows from the economy to the environment (surface water and groundwater).
   

29 The total supply of water in the supply and use tables is a relatively large estimate, as it is the aggregate of four separate supply 'sub-totals':

• Supply from the environment to the economy (i.e. abstractions from the environment);
• Supply of distributed water and reused water (mainly by water utilities) to other users/customers within the economy;
• Supply of wastewater from industry and households to the sewerage industry; and
• Supply of return flows from the economy to the environment (mainly treated wastewater from the sewerage industry to the environment).
   

30 The physical supply and use tables are separated into three main components:

• Flows from the environment to the economy (natural inputs), including surface water, groundwater and rainwater (delivered through rainwater tanks);
• Flows within the economy (products), including distributed water, reused water and wastewater; and
• Flows from the economy to the environment (return flows), including flows to surface water and groundwater.
   

31 The primary data sources for developing the physical supply and use tables were:

• Water Account, Australia (cat. no. 4610.0) (ABS);
• National Water Account (NWA) (Bureau of Meteorology); and
• ACT Government Environment, Planning and Sustainable Development Directorate (EPSD).
   

32 The EPSD provided data for groundwater and self-sourced water use for the ACT, and the Bureau of Meteorology provided groundwater estimates for the NSW component of the region.

33 For information on the methods used in developing the ABS Water Account, Australia (cat. no. 4610.0), please refer to the Explanatory Notes for that publication.

34 Use of rainwater from tanks was modelled for households only, as insufficient data was available for the modelling of industry estimates.

35 Use of soil water and storm water was not included in the physical supply and use tables due to the lack of available data.

36 There are several key differences between these physical supply and use tables and those published in the ABS Water Account, Australia (WAA).

• The reporting boundaries for this publication do not align exactly with the reporting boundaries presented in the ABS WAA. The WAA presents national estimates, as well as all states and territories, and therefore presents estimates for the Australian Capital Territory (ACT), while this publication includes the surrounding water catchment areas in New South Wales that feed into the ACT. This geographic difference is the major factor for the differences in the estimates in the physical supply and use tables in the respective accounts.
• This publication includes wastewater as a product, however wastewater is not included in the physical supply and use tables in the WAA.
• This publication presents the 'water supply' and 'sewerage' industries as separate industries, while the WAA presents them as a combined industry.
• The physical supply and use tables present estimates of water 'consumption', which represents total use less total supply. In the ABS WAA, consumption is defined as total water use (the sum of distributed water use, self-extracted water use and reused water use) less in-stream water use and distributed water supplied to other users. However, this publication follows SEEA's definition; that is, water that is 'consumed' by an economic unit (e.g. business/organisation) is water that has been incorporated into products, evaporated or transpired while being used by that unit. That is, consumption excludes water that is returned to the environment (e.g. via treated wastewater returns or pipes leaking to the groundwater system) and water that is returned to the sewerage system (for households and industry). For this reason, consumption figures presented in this publication will be considerably lower than those presented in WAA. For example, note that the household consumption figures presented in this publication do not include returns to the sewerage system.
   

37 The monetary supply and use section presents aggregates of all available quantitative monetary data (in dollars) in terms of the supply and use of water within the economy, as well the valuation of natural inputs. Supply and use tables illustrate the economic transactions associated with the use of water and the provision of sewerage, drainage and wastewater services (also referred to as 'water-related services' in the ABS Water Account, Australia). Monetary supply and use tables follow the same general structure as the supply and use tables presented in the System of National Accounts (SNA), which is a slightly different format to those presented in the ABS Water Account, Australia.

38 The reporting boundaries for the ABS Water Account, Australia (WAA) do not align exactly with the reporting boundaries for this publication. The WAA presents estimates for states and territories, including the Australian Capital Territory, while the accounts presented in this publication include the surrounding catchment in New South Wales. This explains the small differences in the estimates in the monetary supply and use tables in the respective accounts. Also note that there were small differences between the sewerage services revenue and expenditure estimates presented in this publication and in the WAA, due to slightly different methodologies.

39 The monetary supply and use tables present:

• valuation of natural inputs (ecosystem service of water provisioning);
• supply of distributed water and water-related services in the economy by the following industries: Water Supply; Sewerage and Drainage Services; Mining; Manufacturing; Electricity and Gas Supply; and Other Industries; and
• expenditure on water and water-related services by industries, households and governments.
   

40 The scope for revenue and expenditure is limited to distributed water, reused water and services related to wastewater, sewerage and drainage.

41 Ecosystem services are the many and varied benefits that humans freely gain from the natural environment and from properly-functioning ecosystems. One such service is 'Water provisioning', defined in this publication, in physical terms, by the runoff or water yield (including precipitation) from the catchments within the Canberra region, which provide inflows to the major reservoirs (Keith et al., 2016). Although the ecosystem services of water provisioning are not generally included as a component of SEEA water supply and use flow accounts, it is a significant service provided to society. The water provided by this service is used (abstracted) by the water supply industry as an input to the production of water supplied and used in the economy and is therefore valuable information for inclusion in water accounts.

42 For further information on the scope of monetary supply and use tables, please refer to the explanatory notes in the Water Account, Australia (cat. no. 4610.0).

43 Data presented in the monetary supply and use tables are compiled from a variety of sources. In addition to those used in the physical supply and use tables, the following ABS data were used:

• Consumer Price Index (CPI) (cat. no. 6401.0);
• Australian System of National Accounts (cat. no. 5204.0); and
• National Accounts supply-use benchmarks (unpublished data).
   

44 Data were also sourced from:

• Bureau of Meteorology National Water Account; and
• Icon Water.
   

45 Revenue and expenditure on water and water-related services for industries and households were sourced from the ABS Water Supply and Sewerage Services survey (2013-14 to 2016-17) and the ABS Energy, Water and Environment survey (2014-15), supplemented by Consumer Price Index and administrative data.

46 Some businesses and households self-extract water for their own use, such as water sourced from on-farm dams used for irrigation. Estimates for the value of self-extracted water have not been included in this section due to lack of reliable data.

47 The replacement cost method (i.e. the amount that an entity would have to pay to replace an asset at the present time) was used to value the water provisioning services, broadly following the method recommended by Edens and Graveland (2014). The value of the ecosystem water provisioning service was estimated by calculating the volume of inflows into major reservoirs and then multiplying this by the market price of water supplied in the Canberra region.

48 For information on limitations, assumptions and the methods used for compiling the monetary supply and use tables, please refer to the explanatory notes in the Water Account, Australia (cat. no. 4610.0).

49 The water quality accounts quantify the health and condition of waterways across the Canberra region. The water quality accounts do not have a direct link to the economic accounts, in the sense that changes in quality cannot be directly linked to economic values.

50 The water quality data is based on the data from the Catchment Health Indicator Program (CHIP) developed by the Upper Murrumbidgee Waterwatch Program. The water quality score is based on chemical and physical indicators of water quality, in order to develop an overall measurement of the water catchment health. The CHIP score is based on the water quality indicators plus the Water bug (WB) and Rapid Assessment of Riparian Condition (RARC) scores.

51 The accounts presents water quality/condition at the beginning and end of the reference period, and how quality and condition has changed over time.

52 The water quality accounts include rivers, lakes and catchments within the ACT.

53 The lakes and ponds included are Lake Ginninderra, Yerrabi Pond, Lake Tuggeranong and Lake Burley Griffin.

54 The rivers included are the Murrumbidgee River, Molonglo River, and the Cotter River (upstream of Cotter Dam).

55 The indicators displayed in the accounts are:

• pH (a measure of the acidity or basicity (alkalinity) of a solution);
• Conductivity;
• Turbidity;
• Phosphorus;
• Dissolved Oxygen;
• Nitrate;
• Water bug (WB) score;
• Rapid Assessment of Riparian Condition (RARC); and
• CHIP Score.
   

56 The accounts use the Catchment Health Indicator Program (CHIP) for measuring water quality, with the following ratings:

• 1 Excellent condition;
• 2 Good condition;
• 3 Fair condition;
• 4 Poor condition; and
• 5 Degraded condition.
   

57 The water catchments included are Ginninderra, Molonglo and the Southern region.

58 The water condition data is based on the data from the Catchment Health Indicator Program (CHIP) developed by the Upper Murrumbidgee Waterwatch Program.

59 Data for Lake Burley Griffin was provided by the National Capital Authority.

60 A comprehensive description of the different indicators, how they were measured, the sampling density and how different scores were developed can be found in the Upper Murrumbidgee Waterwatch Catchment Health Indicator program.

61 The Upper Murrumbidgee Waterwatch Catchment Health Indicator program does not provide estimates for Lake Burley Griffin. However Lake Burley Griffin is the largest lake in the Canberra region and therefore has been included in this account. The National Capital Authority provided raw data on the water quality for Lake Burley Griffin, and this was converted to the CHIP scores using the scoring matrix presented in the Upper Murrumbidgee Waterwatch Catchment Health Indicator program. The matrix used is presented below:

62 Dissolved oxygen, Waterbug scores and Rapid Assessment of Riparian Condition (RARC) scores were not available for Lake Burley Griffin. The overall water quality score and CHIP score utilised the average score of the available indicators for the lake.

63 There were no data water quality data available for the Cotter River for the 2013-14 reference period.