The document discusses the risks that proposed infrastructure plans pose to the Mary River's low flows. It argues that removing water from the river and constructing dams will likely exacerbate existing problems during dry seasons, as the river already experiences major issues with low flows. To protect the low-flow regime and mitigate these impacts, significant environmental flow releases would be needed from any new dams, but this would reduce the economic viability of the proposed infrastructure projects. There may be better options for urban water supply than these plans.

1. Why the Mary is at risk from low flows . Steve Burgess Mary River Catchment Coordinating Committee

2.  The Mary River has plenty of flow  We are only removing a comparatively small amount  Therefore we won’t have much adverse impact  The proposed dam is a long way upstream  There are many tributaries and a large catchment downstream  Therefore there will be little impact on the lower river Myth/ unsubstantiated unscientific conclusion 1 Myth/ unsubstantiated unscientific conclusion 2

5. MRCCC

8. Wet end Dry end Water from here Comes out here

9. Gympie Climate (Bureau of Meteorology 1997)

10. Theebine Climate (Bureau of Meteorology 1997)

11. Moy Pocket TC Damsite Fisherman’s Pocket Miva Home Park Barrage End of System

12. River Reach Stream flow in Stream flow out Inflows: tributaries, runoff, groundwater, Losses: extraction, seepage, evaporation, Simple Hydrology

14. River Reach Stream flow in Stream flow out Inflows: tributaries, runoff, groundwater, Losses: extraction, seepage, evaporation, Mid Mary – Dry Seasons Eg. JASON months 1996, 1997, 2002, 2006

20. The Mary River already experiences major problems in times of low flows Proposed infrastructure plans are likely to make these problems worse Protecting the low-flow regime would require significant environmental flow releases This would reduce the economic viability of new infrastructure There are better urban water supply options