Australian Natural Resources Atlas

Natural Resource Topics

Water resources - Management and Development - Queensland

Location map of Isaac River

Groundwater Management Unit: Isaac River

Introduction

Management Context:

The groundwater resource of the Isaac River groundwater management unit is reasonably underdeveloped at present, with no apparent stress currently placed upon the system. However, the groundwater resources are not capable of sustaining major expansion due to the minimal available drawdown of the groundwater system. Therefore, protective management requirement must be developed to ensure that groundwater extraction does not result in localised depletion.

The intrusion of poor quality groundwater is a priority issue for the Isaac River GMU due to the many sections along the flanks of the alluvium where the groundwater is brackish and the possibility of migration if the system is placed under stress.

Priority issues

Declining Water Levels

 NO

Salt Water Intrusion

 NO

SALINISATION

Dryland

 NO

Irrigation

 NO

Groundwater

 YES

Surface Water

 NO

Urban

 NO

Point Source Pollution

 NO

Diffuse Source Pollution

 NO

Subsidence

 NO

Artificial Recharge (ML/yr)

 no data

Ecosystems Protection

 NO

Surface Water Interaction

 NO

Management Plans

 NO

Defined Minimum Water Level

 NO

Comments on Management Responses

2020 Management Response:

The estimate of 30000 Ml/yr for the forecast use for the year 2020 is based upon the GMU's assessed sustainable yield, development potential and the desired level of resource management.

2050 Management Response:

The estimate of 30000 Ml/yr for the forecast use for the year 2050 is based upon the GMU's assessed sustainable yield, development potential and the desired level of resource management.

See QLD Water Resources Assessment 2000 Technical Report for a review of management responses.

Assessment of monitoring in Isaac River

Efficacy of the network:

The current monitoring network for the Isaac River groundwater management unit consists of 33 observation bores, with a proposed bi-annual monitoring frequency.

Data management requirements:

Queensland groundwater monitoring data, both water level and water quality, is stored within the Groundwater Database (GWDB) system. The new system is based on web technology and is available through the Department's intranet. Allocation and use data is obtained through the Water Entitlements Registration Database (WERD) which is 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.

Protective management:

Management of the groundwater resource of the Isaac River GMU aims at maintaining a longterm, sustainable resource and therefore, requires the development of a Water Management Plan (WMP), construction of a broad scale model and the introduction of metering to enable comprehensive aquifer assessment, quantification of the groundwater resource, and facilitate a reassessment of sustainable yield and development potential for the GMU. Protective management requirements for the Isaac River GMU include:

prevention of intrusion of poor quality groundwater from the flanks of the alluvium where the groundwater is brackish and could migrate if the groundwater system is placed under stress.

Options for monitoring:

Options for Commonwealth and State agencies to address data and information gaps include:

the development of a Water Management Plan, construction of a broad scale groundwater model and the introduction of metering of groundwater abstraction, which would increase the resource management of the GMU by allowing for comprehensive aquifer assessment, quantification of the groundwater resource, and enable a reassessment of sustainable yield and development potential for the GMU.

See QLD Water Resources Assessment 2000 Technical Report for a review of monitoring.

What is the estimated demand for groundwater?

Sustainable Yield

Comment about sustainable yield figure: 

An assessment of 30000 Ml/yr for sustainable yield was made in 1999 based upon the hydrogeological characteristics of the aquifer.

Sustainable yield:

ML/yr

Threshold year for sustainable year:

2,010 

Abstraction Volume 1996/1997:

1,300 ML 

Current Resource development categorisation:

Estimated Use in 2020

Comment:

Estimated use in 2020:

30,000 ML 

% change from 1996/1997:

2,208 

Resource development categorisation:

Estimated in 2050

Comment:

Estimated use in 2050:

30,000 ML 

% change from 1996/1997:

2,208 

Resource development categorisation:

 

What assumptions were used in this assessment

Development Potential:

Whilst there is a considerable groundwater resource in the greater region, limited available drawdown limits the development and use of this resource to the better alluvial aquifers. The groundwater resources of the upper Isaac River groundwater management unit are mostly limited and only able to meet the requirements of stockwatering and domestic use. Therefore, the township of Moranbah, although located within the Isaac River GMU, obtains the groundwater component of its town water supply from the Braeside borefield, located in the adjacent Braeside/Nebo GMU, via the 107 km Braeside-Riverside pipeline

Estimate of Use:

The estimate of 30000 Ml/yr for the forecast use for the years 2020 and 2050 is based upon the GMU's assessed sustainable yield, development potential and the desired level of resource management.

Data Availability,Gaps and Recommendations

Data Availablility:

In excess of 200 observation bores, both private and State owned, are located within the Isaac River GMU. The availability of water level data is moderate, with semi-continuous water level monitoring conducted in 33 observation bores from 1969 to the present. Comprehensive water quality data exists for 33 observation bores and

5 gauges within the GMU with sporadic analyses from 1969 to the present.

Current Gaps and Recommendations:

Data Gaps: Intermittent water level data gaps, of up to 3 years, exist in the hydrographs for most bores in the Isaac River GMU. Formal use data is not available, as high use bores are not metered.

Recommendations:

Future Gaps:

The development of a Water Management Plan, construction of a broad scale groundwater model and the introduction of metering of groundwater abstraction would increase the level of resource management of the GMU by allowing for comprehensive aquifer assessment, quantification of the groundwater resource, and enable a reassessment of sustainable yield and development potential for the GMU.

Further information

Key

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