1.1.5 Surface water hydrology and water quality


The Gloucester subregion contains rivers that flow into two separate river basins: the Manning and Karuah river basins. Observed river water quality in the subregion is good. The northern part of the Gloucester subregion sits within the catchment of a major tributary of the Manning River – the Gloucester River – and the southern part is located in the catchment of the Karuah River. The main surface water resources of the Gloucester subregion include the Avon, Gloucester, Barrington, Mammy Johnsons and Karuah rivers, most of which are unregulated. There are several small farm dams in the subregion that store water from new and existing coal seam gas (CSG) exploration wells, and supply water for agricultural irrigation. The average annual streamflow and baseflow indices are respectively 550 and 0.58 GL for the Gloucester River at Doon Ayre, and 270 and 0.50 GL for the Karuah River at Booral. There is no long-term, consistently applied water quality monitoring program in the Gloucester subregion. Water quality information about the northern part is mainly available for the Avon River where there is a large variation in salinity levels, with electricity conductivity (EC) varying from 100 to 1230 µS/cm and pH is near neutral (6.6 to 7.4). In the southern part, for the Karuah River, salinity is less than 400 µS/cm, and pH varies from 6.3 to 8.5.

Last updated:
5 January 2018