2.5.1 Methods


Water balance reporting nodes are selected to quantify impacts of coal resource developments over the minimum possible area which incorporates all hydrologically connected cumulative impacts.

Impacts from mines accumulate along two hydrologically disconnected pathways, the north-flowing Avon River and south-flowing Karuah River. Two nodes were selected for analysis: node 6, located on the Avon River; and node 21, located on the Mammy Johnsons River within the Karuah river basin.

The groundwater domain is defined by the alluvial groundwater modelling domain and differs from the surface water modelling domain. Thus separate water balances are reported for surface water and groundwater.

Three reporting periods are used to summarise water balance terms. These are 2013 to 2042, 2043 to 2072, and 2073 to 2102. They have the same variability as in the 1983–2012 historical sequence, but each of the future 30-year climate blocks assume some level of global warming.

Two possible coal resource development futures have been modelled.

In all, 24 water balances are presented.

Last updated:
12 July 2018