Australian Natural Resources Atlas

Natural Resource Topics

Water resources - Overview - New South Wales

Location map of Lower Gwydir Alluvium

Groundwater Management Unit: Lower Gwydir Alluvium

Introduction

The GMU encompasses the alluvial deposits of the Gwydir Valley, from Binniguy (about 40 km upstream of Moree) westwards almost to the confluence with the Darling River. This area extends westwards beyond the limit of low salinity water, which is largely restricted to the eastern half of the GMU. The northern and southern boundaries are marked by the limit of saturated alluvial deposits, with part of the southern boundary being gradational with the adjoining Namoi Valley alluvial deposits. The alluvium was deposited on a very subdued land surface eroded onto the sandstone and shale of the Great Artesian Basin, and the limits are often poorly defined. In the eastern part of the area the underlying and bounding rocks are the sandstones of the GAB intake beds. Upstream from the GMU, the Gwydir Valley is incised into older fractured rocks of the New England Province, and this has presumably influenced the type of material which comprises the alluvium, but the GMU itself is entirely outside the fractured rock area. Groundwater from the alluvial aquifer has been used for many years for Moree Town Water Supply, and is now also used extensively for irrigation. Cotton is the dominant crop but there are also some cera\eal crops.

Vital Statistics:

Area: 3,407 Km2
Total water allocated: no data
Total water consumed: 81,524 ML/yr
Average salinity: 1,200 mg/l
Sustainable yield: 35,000 ML/yr
Depth to top of aquifier: 10 m

Further Information

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