'Near to final' draft for independent review - 9 May 2016 Table 3: Site-specific flow indicators for small in-channel freshes for the Lower Balonne River Floodplain UEA. In this table, frequency is the percentage of years in which there is a corresponding flow event. The frequency range is shown from low uncertainty to high uncertainty. Magnitude: Basis of magnitude Duration Basis of duration Timing Basis of timing Freq. Basis of frequency flow (ML/d) (days) range 1,000 To provide access to in-stream 7 Duration to Any time At any time of year 90% The condition of – (Culgoa habitat along with a range of achieve of the year would provide 80% aquatic biota River at hydraulic conditions. In- connectivity along benefits of benefits from Brenda) channel inundation beyond the the main connection and regular flows for waterholes. This flow would distributary improved habitat productivity in most provide relatively small-scale channels and condition. years, particularly movement opportunities, potential for drift of for short-lived perhaps to neighbouring pools. biota such as fish aquatic species. There may also be some short larvae. Maintenance of term connection between habitat and regular distributaries, subject to short scale barriers movement opportunities for aquatic species. 1,700 14 Aug - May 60% - In addition to the above, to Linked to the Fish response Re-colonisation of (Narran River trigger fish movement of flow typical duration of expected above the 40% aquatic species. at Wilby dependent specialists, for this size event, and critical water Provide regular Wilby) dispersal and spawning. to the hatch time temperature opportunities for Provides both a 2 m rise and for native fish eggs threshold of 15 mixing of an average velocity (0.3 generally. degrees Celsius. populations metres per second). (genetic diversity) 3,500 As above As As above As above As above As above As above (Culgoa above River at Brenda) Page 58
'Near to final' draft for independent review - 9 May 2016 Table 3: Site-specific flow indicators for small in-channel freshes for the Lower Balonne River Floodplain UEA. In this table, frequency is the percentage of years in which there is a corresponding flow event. The frequency range is shown from low uncertainty to high uncertainty. Magnitude: flow (ML/d) Basis of magnitude Duration (days) Basis of duration Timing Basis of timing Freq. range Basis of frequency 1,000 (Culgoa River at Brenda) To provide access to in-stream habitat along with a range of hydraulic conditions. In- channel inundation beyond the waterholes. This flow would provide relatively small-scale movement opportunities, perhaps to neighbouring pools. There may also be some short term connection between distributaries, subject to barriers 7 Duration to achieve connectivity along the main distributary channels and potential for drift of biota such as fish larvae. Any time of the year At any time of year would provide benefits of connection and improved habitat condition. 90% – 80% The condition of aquatic biota benefits from regular flows for productivity in most years, particularly for short-lived aquatic species. Maintenance of habitat and regular short scale movement opportunities for aquatic species. 1,700 (Narran River at Wilby Wilby) In addition to the above, to trigger fish movement of flow dependent specialists, for dispersal and spawning. Provides both a 2 m rise and an average velocity (0.3 metres per second). 14 Linked to the typical duration of this size event, and to the hatch time for native fish eggs generally. Aug - May Fish response expected above the critical water temperature threshold of 15 degrees Celsius. 60% - 40% Re-colonisation of aquatic species. Provide regular opportunities for mixing of populations (genetic diversity) 3,500 (Culgoa River at Brenda) As above As above As above As above As above As above As above Page 58
EWR-Condamine-Balonne-draft.docx