Salinity situation statement Tweed River and Gnowergerup Brook

Water Resource Technical Series Salinity situation statement: Tweed River and Gnowergerup Brook WRT 41
Figure 41 Flow of response units in 2030 – ‘all cleared’
Scenarios 6 to 15
The greater the cleared area replanted, the smaller the salt loads, flows and salinities for the
lowland and upland trees scenarios. The smallest salt loads and flows came from the ‘100%
trees’ and ‘100% native vegetation’ scenarios, where there were projected salinities of less
than 600 mg/L in 2030 (Appendix F).
The upland and lowland tree plantings of 22–55% of the cleared catchment area both reduce
salt loads and salinities. However, for Gnowergerup Brook, salinities only go down to about
3000 mg/L. For the Tweed River the ‘55% lowland trees’ scenario produced the lowest
salinity of 626 mg/L (Appendix F).
Lowland plantings resulted in lower salinities than upland plantings where similar proportions
of the cleared area were planted with trees (‘22% upland trees’ compared against ‘25%
lowland trees’; and ‘55% upland trees’ compared with ‘55% lowland trees’) (Appendix F).
Department of Water 43