Australian Natural Resources Atlas

Natural Resource Topics

Water - Queensland - Water Technical Report

Surface and Groundwater Management, Availability, Allocation and Efficiency of Use
Queensland Technical Report

Surface Water Methodology

Definition of Surface Water Management Area

For this Audit, the basins as designated by the Australian Water Resources Council (AWRC), have been adopted in Queensland as a reporting unit. A number of these basins have been further subdivided to smaller areas which reflect operational areas within the basin and recent analyses have been carried out on this basis.

All reporting units are referred to as Surface Water Management Areas (SWMAs). A total of 99 SWMAs have been defined.

Compilation of Surface Water Use Data

Licensed water users on regulated streams are metered and water use is recorded.

Licensed water users on unregulated streams have an area to be irrigated allocation. There is no record of water use for these users. Water allocation and use for these users was estimated using crop factors for the dominant crops in the SWMA, the period of irrigation required for the crop and the Potential Areal Evapotranspiration (PET) for the area.

Stock and Domestic users on unregulated streams are not metered and use was estimated to be equal to the allocation.

Accurate water use is difficult to obtain for major users who own their own major storage. These users include local authorities, industrial users and the mining industry. In some areas water supply boards supply urban water and only bulk totals of water supplied are available. In some cases this will cross several SWMAs and will include domestic, industrial and commercial users with no distinction.

There is no record of water diverted by water harvesting.

Water use was obtained from Annual Reports from Water Supply Boards and Government Departments, Australian Bureau of Statistics data, Department of Natural Resources records and direct communication with users.

Compilation of Surface Water Allocation Data

Data for licenses issued by the Department of Natural Resources is held in the Water Entitlements Registration Database (WERD). The conditions on the License vary with the type of License and the location.

Water has been allocated to some local authorities and industries by Order in Council or Government Act. There is no centralised database that includes all of these. Allocations for this group of users were obtained from various reports and internal files of the Department of Natural Resources (Queensland).

Hydrological Characterisation

The key stream gauging stations were selected on the basis of length of record, reliability of data and location. Where possible a gauge was selected to represent a natural part of the catchment and one to the developed part of the catchment.

Natural flows were not derived for all gauges. Where Integrated Quantity-Quality Models (IQQM) models have been developed for the SWMA, this was used to derive the natural flow. IQQM is a daily time step model and is calibrated in reaches using gauged flows, recorded use and stream losses to determine the natural residual inflows to the reach. The natural flows obtained by using the full calibrated model with no demands or storages. Where necessary, the inflows to the model and the residual flows are extended to a standard using calibrated Sacramento models.

Rainfall data was obtained from the Commonwealth Bureau of Meteorology records. Where possible a rainfall station was selected to be representative of the gauged catchment. Where this in not possible, the nearest rainfall station was selected.

Mean Annual Flow and Mean Annual Outflow

The Mean Annual Flow (MAF) for all SWMAs was determined at the outlet of the management area. This assumes that generally all major rivers increase in flow as you progress downstream. The Mean Annual Outflow (MAO) is therefore assumed to be equal to the MAF. Several inland rivers in arid areas were exceptions to this general rule and they have had detailed daily time step models developed (Method 3).

The MAF series was estimated using three methods which are discussed below:

Method 1 - In the majority of SWMAs, the MAF was calculated using a calibrated daily Sacramento Model. Initially, a Sacramento model would be calibrated for an appropriate stream gauge in the catchment using recorded flow data and mean daily rainfall for the gauged catchment. The parameters determined from this calibration were then applied to a Sacramento Model of the SWMA using daily SWMA catchment rainfall for the period 1900 - 1999 to calculate the Mean Annual Flow. Appropriate gauges for calibration had a minimum of 10 years of record and commanded as large a portion of the catchment as possible.

Method 2 - For ungauged SWMA's, the Mean Annual Flow was derived from the daily Sacramento Model of a geographically similar SWMA. This Sacramento Model for the similar catchment was calibrated using Method 1. The parameters determined from the calibrated model were then applied to a Sacramento Model of the ungauged SWMA using mean daily ungauged SWMA catchment rainfall for the period 1900 - 1999 and the ungauged SWMA catchment area to calculate Mean Annual Flow.

Method 3 - Where calibrated Integrated Quantity-Quality Models(IQQM) were available for the SWMA, these were used to determine the natural flow. IQQM is a daily time step model and is calibrated in reaches using gauged flows, recorded use and stream losses to determine the natural residual inflows to the reach. The natural flows obtained by using the full calibrated model with no demands or storages. Where necessary the inflows to the model and the residual flows are extended to a standard using calibrated Sacramento models.

In most SWMAs the MAF is greatest at the outlet of the SWMA and therefor the MAF is equal to the MAO.

For SWMA 011 (Bulloo) the stream terminates in a lake so there is no outflow from the SWMA.

For SWMA 422.D (St. George) and 422.D (Distributary Area) there is a net loss in the SWMA. The inflow is greater than the outflow as a result of high losses caused by overland flow during flooding and high evaporation.

Other streams flowing from Queensland to the Lake Eyre Division and the Murray Darling Division have high losses as they flow south due to flat terrain, braided streams, large overland flows during flooding, high evaporation and low rainfall.

Developed Yield

A number of models have been used to determine the developed yields of the SWMAs. In the past a number of monthly time step models have been used. All new yield analyses are now being carried out using a daily time step model. Historically and assured no failure yield was considered in the state. This is now being changed to a reduced reliability with increasing demands and environmental awareness. The developed yields of most major river systems in the State are currently being reassessed under the Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs) that are currently being developed.

Monthly Models

The main model used for single storage analysis is SORB. This program simulates the operation of a single reservoir by a water balance and salt balance on a monthly time step. The draft can either be a constant or a linear decision rule can be optimised.

One of two models has been used in most cases for system analyses.

WT16 is a set of 2 generalised computer programs that together are used for the monthly simulation of the behaviour of water resource systems. These systems can be as simple as a single storage supplying water directly or a complex system of many reservoirs, aquifers, interbasin transfers, losses, offstream storages or pumping stations.

Water Allocation Model (WAM) is a generalised computer program used for the monthly simulation of the behaviour of water resource systems. In addition to the capabilities of WT16, WAM includes off allocation of supply, water harvesting and announced allocation rules.

Daily Model

All new yield analyses being carried out by the Department of Natural Resources (Queensland) are utilising the daily Integrated Quality Quantity Model (IQQM). The Department of Land and Water Conservation in New South Wales have developed this model with some assistance from the Department of Natural Resources (Queensland).

IQQM is a generalised hydrologic package that is applied to regulated and unregulated streams and addresses water quality and environmental issues as well as quantity issues. In quantity modelling, the model can handle processes such as flow routing, reservoir operation, resource assessment and accounting, irrigation, urban water supply, wetland and environmental flow requirements, unregulated demands, power station demands, floodplain storage behaviour, water sharing issues and transmission losses. The model is designed to operate at a daily time step, but some processes and be simulated at time steps down to one hour.

Developed yields are not available for most privately owned storages.

Divertible Yield

Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs) are currently being developed for many catchments throughout the state. These Plans will guide the future development of the catchments and identify the future availability of water. Under the Statuary Instruments Act 1992, the life of a Plan cannot exceed a period of 10 years and at that time must be reviewed and either amended or renewed.

Environmental Flow Requirements

There are currently no specific environmental allowances made in most areas of Queensland.

Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs) are currently being developed for many catchments throughout the state. Environmental strategies are being developed as part of these plans. These will guide the future development of the catchments.

Sustainable Yield

Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs) are currently being developed for many catchments throughout the state. These will guide the future development of the catchments and identify the future availability of water.

Categorisation

Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs) are currently being developed for many catchments throughout the state. These will identify the availability of water for future expansion and also any areas where the resource is stressed.

Management Goals and Objectives

Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMP) will have the primary role in managing the surface water resources of the State. These plans have been introduced because of the general acceptance that water is a limited resource.

WAMPs proactive, basin-wide approach sets it apart from the present licensing system by placing a high priority on community consultation and sustainability of the resource. WAMP adopts an integrated approach that is based on the best available ecological, social and economic data, and involves extensive basin-wide hydrologic analysis and community consultation. The WAMP process provides the opportunity for local catchment communities to work on draft plans in partnership with the Department of Natural Resources, primarily through a Community Reference Panel, but also through public consultation. This will ensure the WAMP results in the best and fairest mix of present and future uses, while finding a balance with environmental needs in accordance with the principles of sustainable ecological development.

Once a WAMP is completed, all future water resource development proposals, including any water trading proposals, will be assessed to ensure that the environmental flows and the water entitlements defined in the Plan are not compromised. The Plan will result in an improved specification of both water users' entitlements and secure healthy river systems for the long term.

The Water Management Planning process (WMP) provides a set of policies, principles and guidelines for decision on applications to take water from selected areas of Queensland. The WMP has statutory effects under the 'Water Resources Act 1989'.

Groundwater Methodology

The methodology for groundwater resource assessment was similar for all Groundwater Management Units (GMUs) and Unincorporated Areas (UAs). Initially, GMUs and UAs were identified and spatially defined using GIS applications. This enabled digital data to be distributed spatially, allowing for the accurate reporting of information specific to a GMU/UA boundary.

Once a GMU/UA had been defined, digital data were collected and collaborated from the Queensland Department of Natural Resources (DNR) Groundwater Database. Data collected from this source was bore data such as groundwater levels, groundwater quality, aquifer dimensions (thickness, depth to top of aquifer), bore locations (latitude, longitude, elevation), and lithological logs. This data formed the basis for groundwater resource assessment particularly through data obtained from monitoring bores where trends could be established.

Abstraction and allocation data were obtained from another Queensland DNR database - the Water Entitlements Registration Database (WERD). Results of WERD searches were compared to those either documented in reports or estimated by the DNR district or regional staff. Generally, allocations drawn from the WERD were similar to those on record at DNR offices. Abstractions however were often conflicting. The main reason for this confliction was that the WERD was limited to metered use data and many production bores within Queensland are not fitted with water meters. Therefore district and regional estimates were often the best source for complete abstraction data.

Literature was reviewed in order to provide information for sustainable yield estimates, GMU/UA descriptions, aquifer descriptions (lithology, confined/unconfined/semiconfined, etc) the source of recharge, and priority issues. It was also beneficial to use reports to check that data retrieved from the database were compatible with previous studies.

Queensland DNR district and regional staff were utilised for their knowledge of the groundwater resources under their management. This source of information was important in checking the accuracy of data obtained through all methods and reviewing GMU/UA documents. In addition information was obtained from staff on priority issues, allocation and abstraction, monitoring strategies, licensing policy, current and desired management, and development potential.

Cross-referencing between sources was typical before data were finalised into the database or the GMU/UA documents to ensure the integrity of the data.

Definition of Groundwater Management Unit Boundaries

The initial step in defining the GMU boundary was to determine the extent of the aquifer system that made up the Management Unit. This was done by geological methods - mapping of alluvium - determination of the extent of fracturing in the case of volcanic formations. This shape was overlain by coverage of property boundaries from the Digital Cadastral DataBase (DCDB). The properties that intersected or were wholly contained within the aquifer description then formed the Groundwater Management Unit.

The DCDB was chosen for easier definition of the boundary and it was concluded that if a property had partial access to an aquifer, the groundwater could easily be transferred to any part of that property. Abstraction records are usually based on a cadastral system.

The Unincorporated Areas (UA) were defined, as the remaining area of the State not covered by a GMU. The UAs were grouped into common geological areas.

The boundaries of the GMU's for the Great Artesian Basin were derived from information supplied by the Great Artesian Basin Technical Working Group.

The Province boundaries were defined for the 1985 Review and are as presented by the Bureau of Mineral Resources in the hydrology report of 1987.

Groundwater Abstraction

Use data is obtained primarily through the Water Entitlements Registration Database (WERD) which is an electronic database for water licenses. It is a secure statewide system to which operators have relevant levels of access to carry out different processes in relation to licenses. This database commenced operation in late 1998 with conversion of data from existing databases.

The database is managed locally at district level, with respect to the collection and entering of water allocation and uses data; and is accessed statewide. The current data management and access arrangements are to be maintained and constantly updated with new technological improvements for greater efficiency in data access and management.

Results of WERD searches were compared to those either on record or estimated by the DNR district or regional staff. Abstractions were often conflicting. The main reason for this confliction was that WERD was limited to metered use data and the many production bores within Queensland are not fitted with water meters. Therefore district and regional estimates were often the best source of abstraction data.

Groundwater Allocation

Allocation and use data is obtained primarily through the Water Entitlements Registration Database (WERD) which is an electronic database for water licenses. It is a secure statewide system to which operators have relevant levels of access to carry out different processes in relation to licenses. This database commenced operation in late 1998 with conversion of data from existing databases.

The database is managed locally at district level, with respect to the collection and entering of water allocation and uses data; and is accessed statewide. The current data management and access arrangements are to be maintained and constantly updated with new technological improvements for greater efficiency in data access and management. A recent advancement in the data collection and management process is the introduction of hand-held data loggers which enables direct download of field collected data.

Selection of Key Monitoring and Major Abstraction Bores

Key monitoring and major abstraction bores were selected by a series of culling processes until a maximum of 20 bores remained. The selection criteria for the 20 key monitoring bores and the 20 major abstraction bores varied for each GMU.

In 1997, a review commenced into the Queensland Groundwater Monitoring Network. Part of this review involved an assessment of the spatial distribution of groundwater level and groundwater quality monitoring bores throughout the state, and of each monitoring bore's condition, and their intrinsic value as a monitoring point. This network formed the initial set of bores from which the key monitoring bores were chosen.

The monitoring network was culled to those bores that fall within the GMU/UA boundary. The amount of information available was then considered. Bores were selected according to the length of the period of monitoring record, the frequency of monitoring, and the most recent groundwater quality measurement taken. This was to provide the most recent and longest data record available so that groundwater trends could be established. If need be, bores were further discriminated by their spatial distribution so that all areas of the GMU would be covered by the key bores.

Problems arose when the monitoring network did not cover the GMU/UA. An example of this was the Koumala GMU where the resource was a new area of groundwater interest and monitoring bores had not yet been established. Private bores were selected to give an indication of groundwater level and quality. Another example is the Weipa GMU where the resource was primarily monitored by mining enterprises. In this circumstance, monitoring data were unobtainable.

Major abstraction bores were selected from all production bores within the GMU/UA boundary where abstraction data were available. These bores were ranked according to the volume of groundwater abstracted during the reporting year (1996/1997). The highest abstracters were chosen as the major abstraction bores.

An exception to this selection process for major abstraction bores can been seen in the Don River GMU. Major abstraction here was reported according to sub-areas within the GMU, so that the volume abstracted during 1996/1997 was reported for each sub-area rather than on a license basis.

Groundwater Level Change Assessment

Groundwater levels are generally measured periodically from monitoring bores. These measurements were extracted from the Queensland DNR Groundwater Database and were plotted as bore hydrographs as part of the Monitoring Network Review. Groundwater level change assessment was achieved by analysing the groundwater level trends described in the bore hydrographs for the selected key monitoring bores.

Bore hydrographs were compare with rainfall trends to determine the cause of groundwater level fluctuation. The majority of the comparisons revealed that groundwater level fluctuations tend to be in response to rainfall events. The magnitude of the fluctuations was influenced by the amount of local abstraction occurring in relation to the hydrographs. Typically, drought seasons resulted in increased abstraction to produce an overall groundwater level decline. Conversely, periods of above average rainfall resulted in decreased abstraction to produce general groundwater level rises. These trends were typical of most GMUs.

Recently the major trend in groundwater levels across Queensland has been a groundwater level decline. This correlates with more than half the GMUs being overabstracted or approaching the optimum level of abstraction (category 3 and 4 by abstraction) and a ten year period of predominantly below average rainfall. In areas of regionally low level abstraction, groundwater levels have remained relatively static, particularly along the far North Queensland coast.

Exceptions to this general decline can be noted in a number of GMUs in the Condamine River Basin (basin number 4223) where surface water infrastructure in the Upper Condamine River System has resulted in more frequent flows downstream and increased aquifer recharge. This has resulted in a gradual rise, during the late 1990s, in groundwater level depicted in hydrographs of bores located adjacent to the river.

In the Great Artesian Basin GMUs, groundwater (potentiometric) level change was assessed using regional drawdown information presented in the GAB Resource Study (GABCC, Nov. 1998) report.

Groundwater Salinity Determination

Groundwater salinity for all sub-artesian GMUs was determined using data extracted from the Queensland DNR Groundwater Database. Generally all bores in the database underwent water quality assessment at the time of bore construction. Monitoring bores were assessed more frequently but at irregular intervals. In order to provide an accurate assessment of the current groundwater salinity, pre-1990 analyses were usually eliminated from the dataset. In some cases, post-1990 data were unavailable and the most recent data were used within reason (eg late 1980 data).

Groundwater salinity was based on Electrical Conductivity (EC) field test readings. For the purpose of complying with the Audit salinity classification fields, EC measurements required conversion to TDS (mg/l). A statewide group of bores with both field measurement EC and water quality laboratory TDS results were plotted against each other. A linear relationship was determined. The relationship was that TDS equalled 0.6625 (conversion factor) of the EC. This conversion factor was applied to the EC measurements of the selected bores recorded on the Queensland DNR Groundwater Database for each identified GMU.

For the Great Artesian Basin GMUs, groundwater salinity (minimum, median and maximum) was determined using the same bore information that led to the summaries presented in the GAB Resource Study (GABCC, Nov. 1998) report.

The salinity classes used in the Audit are defined in the table below. Note that the table also includes the suggested salinity classes adopted in Queensland.

Audit Salinity Classes Suggested Salinity Classes
TDS (mg/l) Class TDS (mg/l) Suitable Limit For
0 - 500 Fresh < 1 000 Drinking
500 -1 500 Marginal 1 000 - 3 000 Lucerne
1 500 - 5 000 Brackish 3 000 - 5 000 Cattle
5 000 - 14 000 Saline 5 000 - 14 000 Sheep
> 14 000 Highly saline > 14 000 Unsuitable

Salinity records in each GMU were sorted to establish the minimum, maximum and median salinity levels. Salinity classes were not assigned due to the Audit classes not being compatible with those considered suitable for Queensland as described above.

Generally, groundwater salinity varied throughout the state. GMUs located on the coast had a wider salinity range than those located inland. The large range in salinity in the coastal GMUs was attributed to saltwater intrusion issues common at these locations. Overall, the average median salinity for coastal GMUs was approximately 800 mg/L while inland, the average median salinity was approximately 1500 mg/L. The irregular interval of water quality sampling made establishing trends difficult, however the general trend appeared to be that groundwater quality had been relatively static.

Sustainable Yield

The sustainable yield has been defined as the groundwater extraction regime, measured over a specified planning timeframe that allows acceptable levels of stress and protects the higher value uses associated with the total resource.

The definition is framed around an extraction regime - not just an extraction volume. The concept here is that a regime is a set of extractions that is defined over time, and puts forward the view that sustainability is measured over a time frame. Extraction limits may be volumetric, extraction rates, related to maintaining water levels and water quality or a combination of the above.

There is an acceptance that there will be stress on the total system as a result of removing groundwater. This embodies the concept of trade off to minimise the stress caused.

There is an explicit reference to trade offs between the values of the uses that the groundwater can be put to. There is no reference to how these trade offs are decided - that is an issue for jurisdictions. This might include lengthy stakeholder consultations, or it might be more pragmatic in groundwater systems where a redefinition of sustainable yield is the imperative.

The definition is in terms of the total system, that is, both groundwater and surface water and implies that integrated management decisions must be undertaken to fully satisfy its spirit. Mining groundwater is an unsustainable activity and is discouraged by all jurisdictions. Use of non-renewable fossil groundwater to sustain important social and economic infrastructure lies outside of the definition of sustainable yield and requires agreement from a broad spectrum of the community.

Categorisation

Categorisation by abstraction and allocation for Queensland GMUs/UAs was achieved as outlined in the Project Specifications (ie. The proportion of allocation/abstraction in relation to the sustainable yield). GMUs and UAs that had no sustainable yield estimate were not categorised by allocation or abstraction.

GMUs and UAs that had no allocations were assigned to category 1 for allocation. In these cases, zero allocation was interpreted as having less than 30% of the resource allocated (category 1).

GMUs and UAs that had no abstraction data were generally not assigned a category for abstraction due to a reluctance to assign a category based on very limited or no data. In some cases, district and regional staff were able to suggest an overall level of abstraction so that a category could be assigned however, these suggested abstraction levels were presented with a low degree of confidence.

Management Goals and Objectives

DNR district and regional staff were asked to describe/respond to the current and desired level of management for the GMUs. The majority of comments referred to the degree of licensing and the licensing policy in place, the criteria for allocations, groundwater monitoring, and priority issues.

Management goals and objectives were regularly outlined in management guidelines that were established with input from community consultation. Management issues such as saltwater intrusion, rising or declining groundwater levels, pollution, and other water quality issues were often documented in reports.

Assessment of Joint Groundwater and Surface Water Use

Assessment of joint groundwater and surface water use in Queensland required that there be known or estimated use of both groundwater and surface water within an SWMA. Overlapping groundwater and surface water use data identified 85 of the Queensland SWMA's to contain, or partially contain, Groundwater Management Unit's. Where there was an overlap, it was considered that there was potential for joint use. Levels of connectivity and type were then assigned.

All sub-artesian and Great Artesian Basin recharge areas were considered to have physical connectivity. Generally the physical connectivity was of a medium level however, sand island GMUs were assigned a high connectivity due to the porosity of the aquifer material and the high response to recharge depicted in bore hydrographs.

All overlapping SWMAs and GMUs are considered to have management connectivity. It is anticipated that a Water Allocation and Management Planning (WAMP) or Water Management Planning (WMPs) process will cover all of Queensland's basins.

Significant groundwater Recharge works have been installed on Cressbrook Creek (SWMA143.A), Lockyer Creek and tributaries (SWMA 143.B), Three Moon Creek (SWMA 136.D), Lower Burdekin (SWMA 120.A) and Callide Creek (SWMA 130.D).

Development Potential

The level of development potential for all Groundwater Management Units was determined in consultation with district and regional DNR staff. Consideration was given to current allocation and abstraction levels (where known or estimated); sustainable yield estimates; and issues such as rising or declining groundwater levels, groundwater quality deterioration, and saltwater intrusion.

Low or no development potential was assigned to GMUs where allocation or abstraction levels had reached or were approaching the optimum level of development. It was assumed that without any major water infrastructure development, development potential for the GMU was low to none.

Demand for Water

The future demand for groundwater within all Groundwater Management Units was determined in consultation with district and regional DNR staff. Consideration was given to current allocation levels; sustainable yield estimates; and issues such as rising or declining groundwater levels, groundwater quality deterioration, and saltwater intrusion. It was assumed that groundwater management would ensure that future allocation and abstraction levels would be maintained at near or below sustainable levels. Therefore, the majority of estimates for future groundwater demand are equal to or less than the sustainable yield quoted.

For GMUs that had a ten year or more period of record for allocations, a graph was made to show the trend of allocations increasing with time. This trend was projected for the years 2020 and 2050 to forecast the demand.

Stock and domestic licenses were ignored in the estimations, as they were deemed negligible for most GMUs when compared to the scope of other uses such as irrigation.

Future demands were not estimated for surface water.

Traditionally water for irrigation in Queensland has been allocated on an assured yield basis. This is changing as the resources of the State are reassessed and a risk approach has now being introduced. More than 78% of the States water use is for irrigation. The demand for changes in irrigation demand is driven by the demand for the crop and this in turn is affected by world markets.

Emerging industries such as mining or manufacturing can cause short or long term demands for water.

Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs) are currently being developed for much of the State.

Surface Water demands in Queensland currently come from irrigation (2171000ML), urban (593000ML) and industrial (267000ML) users.

Future requirements are currently being assessed in the major use areas with the formulation of Water Allocation and Management Plans (WAMPs). Results of these studies will be released as they are completed. Under the Statuary Instruments Act 1992, the life of a Plan cannot exceed a period of 10 years and at that time must be reviewed and either amended or renewed.

Constraints to Development

The main constraint on groundwater development was the sustainable yield estimate of the resource. Many GMUs had already exceeded the threshold year for sustainable yield and therefore had no development potential. Other constraints included the consideration for saltwater intrusion in the coastal GMUs; rising groundwater levels; and water quality.

The sustainable yield was the main constraint to development, so increasing the sustainable yield through artificial recharge would enhance groundwater development. However, the costs involved in water infrastructure have in many cases (particularly in the Condamine River Basin) been deemed unfeasible.

Future development of surface water resources in Queensland are constrained by the availability of suitable storage sites, the demand for water in isolated areas, and the management plans which are being developed. In common with groundwater resources, National Parks, State Forests and World Heritage Areas, will impose some limits on development.

Cultural and historic issues that consider the importance of retaining an appreciation of influences of the past, respect for the original inhabitants and new settlers who developed the region and the relevance of the regions history are also considered when considering the direction of future development.

The WAMP process will guide future developments and reviews will be carried out at regular intervals.

Cost of Water

No cost estimates have been carried out for future surface water or groundwater supplied in Queensland.

Forecast Use

Forecast use was defined as the future groundwater abstraction estimated for a Groundwater Management Unit over a specified year (ie. 2020 and 2050). This was determined in consultation with district and regional DNR staff. Consideration was given to current abstraction levels (where known or estimated); sustainable yield estimates; and issues such as rising or declining groundwater levels, groundwater quality deterioration, and saltwater intrusion. It was assumed that groundwater management would ensure that future allocation and abstraction levels would be maintained at near or below sustainable levels. Therefore, estimates for future groundwater use were equal to or less than the sustainable yield quoted.

For GMUs that had several years of record for abstraction, a graph was made to show the trend of abstraction increasing with time. This trend was projected for the years 2020 and 2050 to forecast the level of abstraction.

Stock and domestic licenses were ignored in the estimations, as they are deemed negligible for most GMUs when compared to other purposes such as irrigation.

Forecast use estimates for the years 2020 and 2050 were not made for surface water use in Queensland.

Past experiences indicate that demands for water from urban, industrial and agricultural users will increase. Unmanaged growth in demands will place considerable strain on existing infrastructure and available water resources.

The approach of demand management is to reduce demand for water through minimising wastage and reducing consumer demands. This can delay the need for capital investment, reduce operating costs, minimise environmental impacts on natural systems and provide additional water for new users. In parts of Queensland the urban use is as high as 1000ML/person/day. Experiences in some areas indicate that demand management can reduce water demands by 20 - 30% for urban consumers.

Currently 78% of water use in Queensland is for irrigation. Major crops such as sugar cane and cotton are dependent on world markets for sales. Changing crops in an area can significantly change the water requirements.

Future development in Queensland is to be guided by the WAMPs that are currently being developed. Under the Statuary Instruments Act 1992, the life of a Plan cannot exceed a period of 10 years and at that time must be reviewed and either amended or renewed.

Industrial use is largely associated with the mining and power industries.

Data and Information Gaps

Generally there was a reasonable amount of groundwater data available for the GMUs. However, there was a limited amount of data available for the Unincorporated Areas (UAs). The groundwater resources of the UAs were rarely documented. The majority of information was drawn from explanatory notes on geological map sheets.

A monitoring bore network has been established across the state. There was a good coverage of monitoring bores within GMU boundaries. Outside these areas of groundwater interest, monitoring bores are sporadically distributed.

Groundwater levels are usually monitored quarterly from monitoring network bores. The groundwater level records frequently span a period of 20 years or more, which enables trends to be observed through bore hydrographs. Groundwater quality was much less frequently monitored.

There has been little variation in groundwater quality throughout the state, subsequently broad-scale sampling has not occurred in many GMU for up to 10 years. In areas where groundwater quality was a priority issue, such as saltwater intrusion in coastal aquifers, groundwater samples are taken on a bi-annual or annual basis.

Groundwater use data were available for 80 GMU/UAs. The groundwater data for 21 of theses GMU/UAs was based on metered used data and only included groundwater abstracted from metered bores. The other 59 GMU/UAs had only estimated groundwater usage data available. This was a major gap in groundwater data that occurred throughout the state.

During this study the following data and information gaps were identified.

Little yield data available for privately owned storages.

Data Management

Groundwater data was readily available in hardcopy, database, spreadsheet, GIS and text format.

Queensland groundwater monitoring data, both water level and water quality was stored within the Groundwater Database (GWDB) system. The new GWDB system was based on web technology and was available through the Department's Intranet. Information was retrievable in a text format or could be exported as a spreadsheet.

Allocation and use data was obtained through the Water Entitlements Registration Database (an electronic database for water license details).

Both databases are managed locally at district level, with respect to the collection and entering of water monitoring, allocation and use data; and are accessed statewide.

Hardcopy data of maps and plans is managed at the Plan Room in the DNR Mineral House office. All maps and plans have been catalogued and copies are available upon request. Similarly, digital copies of a large range of maps and plans are available through the GIS library that is managed and updated by a member of the DNR Groundwater Assessment group.

Groundwater data is being used in many groundwater projects throughout the state as well as in everyday administrative use. The data sources are heavily utilised, particularly the Groundwater Database, for groundwater modelling; developing groundwater monitoring strategies and networks; and more recently as input into Water Allocation and Management Plans (WAMPs) and Water Management Plans (WMPs).

Streamflow and water quality data were readily available for the DNR HYDSYS database. Data can be extracted from this database in various forms and limited statistical analysis is also available. This is an electronic database and is updated continuously.

Allocation and some use data for licenses issued by DNR were obtained from the Water Entitlements Registration Database (WERD). Some of the use data was obtained from summaries produced by this DNR and various Water Boards. Allocations for users who operate under an Order in Council or Government Act were obtained from various departmental internal files.

Storage data was obtained from a list of referable storages in Queensland. The list is maintained by the Dam Safety Group of DNR and they are responsible for licensing of referable dams.

Future Research and Development

In conjunction with the WAMPs and WMPs, daily IQQM models are being developed to simulate and assess streamflows, water infrastructure performance, losses and use for many catchments. IQQM models are very data intensive and require daily data. Previous models used by DNR have used monthly data. Improved data collection procedures are required to obtain adequate data for to produce accurate models.

Also in conjunction with the WAMPs, Technical Advisory Panels are being formed to advise on environmental matters.

References

Australian Water Resources Council (1987) 1985 Review of Australia's Water Resources and Water Use Volume 1 and 2, November 1987. Australian Government Publishing, Canberra.

Bjornsson, B. Oehlerich, G. and Sturgess, B. (Unpublished Report 1999) Risk Assessment of Queensland Aquifers For the Current State of Development, October 1999. Department of Natural Resources, Water Assessment and Planning, Resource Condition and Trend, Resource Science and Knowledge.

Great Artesian Basin Consultative Council (1998) Great Artesian Basin - Resource Study, November 1998. Queensland Department of Natural Resources, Brisbane.

Queensland Department of Local Government and Planning, FNQ2010 Integrated Regional Strategies for Far North Queensland, Draft Report for Public Consultation, March 1998

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