Australian Natural Resources Atlas

Natural Resource Topics

Water resources - Overview - South Australia

Location map of Muloorina (Wellfield B)

Mound spring near Muloorina (GAB) Source: Department for Water Resources

Groundwater Management Unit: Muloorina (Wellfield B)

Introduction

The Great Artesian Basin (GAB) is the largest artesian groundwater basin in the world and extends beneath Queensland, New South Wales, South Australia and the Northern Territory. The basins areal extent is in excess of 1.7 million km2, of which 310 000 km2 lies within South Australia. The GAB is an essential water resource for northern South Australia and supplies water for the pastoral, agricultural and mining industries, and also small communities.

Aquifer recharge to the GAB occurs by direct infiltration of rainfall through outcropping units in the Great Dividing Range in central Queensland, with minor recharge occurring around the southern and western margins. The rate of recharge to the GAB in South Australia is estimated at 425 ML/day, which is the same rate as the estimated use of the resource. Data from 1996 indicates discharge from the aquifer in South Australia occurs via upward leakage (45%), flowing bores (30%), natural discharge from mound springs (15%), petroleum activities using over 5% and bores supplying Olympic Dam extracting over 3.5% of the recharge.

Water for the Olympic Dam Operation is extracted from two prescribed areas, Curdimurka commonly known as Wellfield A and Muloorina known as Wellfield B. The wellfields are respectively located 100 and 200 km north of the mine in the GAB. These areas were prescribed to provide Olympic Dam mining operations, and Roxby Downs Township, with a water supply while protecting nearby ecologically significant mound springs.

Water is extracted from Wellfield A and Wellfield B Prescribed Wells Areas under special water licences issued under the Indenture Act (Roxby Downs (Indenture Ratification) Act 1982). The extraction of water is subject to a number of conditions including drawdown limits set at the boundaries of the designated areas.

Vital Statistics:

Area: no data
Total water allocated: no data
Total water consumed: 11,000 ML/yr
Average salinity: 1,300 mg/l
Sustainable yield: no data
Depth to top of aquifier: 470 m

Further Information

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