2.3.2.5 Water balance

The current surface water and groundwater water usage in the Richmond river basin is shown in companion product 1.5 for the Clarence-Moreton bioregion (McJannet et al., 2015). The total storage volume of two main surface water reservoirs and several small dams and weirs in the Richmond river basin is around 25 GL. The current surface water licences permit a maximum water extraction of 99,881 ML/year from the Richmond river basin. It is estimated that 11,618.5 ML of groundwater is allowed to be used annually from 2,505 bores based on the current water allocation data within the groundwater model domain (Figure 10 and companion product 2.6.2 for the Clarence-Moreton bioregion (Cui et al., 2016b)). Of the estimated water usage, 49.5% and 42% are allocated for irrigation and domestic/stock bores, respectively.

A water balance assessment was conducted in companion product 2.5 for the Clarence-Moreton bioregion (Cui et al., 2016a) using the outputs from the surface water and groundwater models that are reported in companion products 2.6.1 and 2.6.2 for the Clarence-Moreton bioregion (Gilfedder et al., 2016; Cui et al., 2016b, respectively). The water balance components were derived from 30 models constrained by historical observations in water levels, a CSG water production forecast and a baseflow estimate at the river stage gauging station near Casino (Figure 27). The water balances are reported for three 30-year periods (2013 to 2042, 2043 to 2072 and 2073 to 2102) for both the baseline coal resource development (baseline) and the CRDP. The surface water balance was calculated at four nodes. An additional reduction of 321 ML/year in groundwater storage occurs due to the West Casino Gas Project from 2013 to 2042. However, the overall groundwater balance impact of the West Casino Gas Project over the entire model domain is very small based on the current groundwater model conceptualisation. Groundwater storage exhibits a future decline even without the impacts of the West Casino Gas Project, although the mean annual reduction is well below 0.5% of the corresponding mean annual recharge for all the three reporting periods.

Last updated:
11 July 2017
Thumbnail images of the Clarence-Moreton bioregion

Product Finalisation date

19 January 2017