Page 75 - VEWH Seasonal Watering Plan 2020-21
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Table 2.4.2 Potential environmental watering for the Macalister River under a range of planning scenarios
2.4 Macalister system
 Planning scenario
   Drought
   Dry
   Average
   Wet
   Expected river conditions
 • No natural flow
• Passing flows at Maffra Weir reduced
 • Possible spills from Lake Glenmaggie in spring, minor flood levels may occur
• Passing flows at Maffra Weir may be reduced
 • Regular spills from Lake Glenmaggie
in spring, minor to moderate flood levels may occur
 • Large and frequent spills from Lake Glenmaggie, moderate to major flood levels may occur
 Expected availability of water for the environment
   • 16,500 ML
   • 19,800 ML
   • 21,800 ML
   • 26,300 ML
   Potential environmental watering – tier 1a (high priorities)
 • One autumn fresh (reach 2)
• Autumn/winter low flow (reach 1 and 2)
• Spring/summer low flow (reach 1 and 2)
• One winter fresh (reach 2)
• One spring fresh (reach 2)
• One summer/autumn fresh (reach 2)
• Trigger-based summer/autumn low flow (reach 2)
 • One autumn fresh (reach 2)
• Autumn/winter low flow (reach 1 and 2)
• Spring/summer low flow (reach 1 and 2)
• One winter fresh (reach 2)
• One spring fresh (reach 2) or spring/ summer fresh (reach 1 and 2) following spill
• One summer/autumn fresh (reach 2)
• Trigger-based summer/autumn low flow (reach 2)
 • One autumn fresh (reach 2)
• Autumn/winter low flow (reach 1 and 2)
• Spring/summer low flow (reach 1 and 2)
• One winter fresh (reach 2)
• One spring fresh (reach 2) or spring/ summer fresh (reach 1 and 2) following spill
• One summer/autumn fresh (reach 2)
 • One autumn fresh (reach 2)
• Autumn/winter low flow (reach 1 and 2)
• Spring/summer low flow (reach 1 and 2)
• One winter fresh (reach 2)
• One spring/summer fresh (reach 1 and 2) following spill
• One summer/autumn fresh (reach 2)
 Potential environmental watering – tier 1b (high priorities with shortfall)
  • Two additional summer/autumn freshes (reach 2)
  • Two additional summer/autumn freshes (reach 2)
• Extend low flow duration through winter/spring if Lake Glenmaggie spills
  • Extend low flow duration through winter/spring following Lake Glenmaggie spill
  • Extend low flow duration through winter/spring following Lake Glenmaggie spill
 Potential environmental watering – tier 2 (additional priorities)
   • Extend duration of delivering low flows through winter/spring months
   • One additional winter fresh (reach 2)
   • One additional winter fresh (reach 2)
   • One additional spring/summer fresh (reach 2)
   Possible volume of environmental water required to achieve objectives1
 • 16,200 ML (tier 1a)
• 6,600 ML (tier 1b)
• 1,200–3,600 ML (tier 2)
  • 18,000 ML (tier 1a)
• 7,800–10,200 ML (tier 1b)
• 4,900 ML (tier 2)
  • 20,400 ML (tier 1a)
• 1,200–3,600 ML (tier 1b)
• 4,900 ML (tier 2)
  • 25,800 ML (tier 1a)
• 1,200–3,600 ML (tier 1b)
• 4,900 ML (tier 2)
  Priority carryover requirements
  • 1,500–1,900 ML2
  1 Environmental water requirements for tier 2 actions are additional to tier 1 requirements.
2 Priority carryover volumes have been incorporated into tier 1a demands.
Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21 | 73
 






















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