Page 121 - VEWH Seasonal Watering Plan 2020-21
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Table 3.6.1 Potential environmental watering actions and objectives for the Moorabool River
3.6 Moorabool system
 Potential environmental watering action
  Functional watering objectives
  Environmental objectives
    Summer/autumn low flow (five ML/day continuous during December to May)
    • Maintain pool and riffle habitats for fish, waterbugs, platypus and submerged aquatic vegetation
• Maintain water quality for biota during summer/autumn by reducing periods of low oxygen, high temperature and high electrical conductivity
                  Winter/spring low flow (10–60 ML/day continuous during June to November)
 • Maintain connectivity and allow fish movement through the reach
• Reduce intrusion by terrestrial vegetation into the stream bed
         Autumn fresh (one fresh of 60 ML/day for five days during April to May)
    • Provide a cue for the downstream migration and spawning of Australian grayling
• Allow fish and platypus to move through the reach to access habitat
• Maintain the condition of streamside vegetation
• Flush silt and scour biofilms and algae from streambed and substrates to improve habitat quality for waterbugs
                    Summer fresh (one fresh
of 60 ML/day for five days during January to February)
  • Provide a cue for downstream spawning and migration of short-finned eel
• Allow fish and platypus to move through the reach to access habitat
• Maintain the condition of streamside vegetation
• Flush silt, scour pools and remove biofilms from hard substrates
• Maintain water quality for biota by reducing periods of low oxygen, high water temperature and salinity
                Spring fresh (one or two freshes of 80–162 ML/ day for five days during September to November)
      • Trigger the upstream migration of juvenile galaxias, tupong, short-finned eel and Australian grayling
• Provide connectivity to support fish and platypus movement and maintain access to habitat
• Scour biofilms and algae from the streambed and transport organic matter
• Promote the growth and recruitment of streamside vegetation
                   Winter fresh (one fresh of 80–162 ML/day for five days during May to August)
     • Trigger the downstream spawning migration of tupong
• Allow fish and platypus to move through the reach and maintain access to habitat
• Scour biofilms and algae from the streambed to maintain waterbug communities and transport organic matter to prevent blackwater events
• Promote the growth and recruitment of streamside vegetation
              Summer/autumn fresh (one fresh of 30 ML/day for five days during February to March)1
 • Maintain water quality for biota by reducing periods of low oxygen, high water temperature and salinity
     1 This event is trigger-based, to be delivered if water quality deteriorates to an extent that is harmful to aquatic life.
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