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Table 3.7.2 Potential environmental watering for the upper Barwon River under a range of planning scenarios
3.7 Barwon system
 Planning scenario
   Drought
   Dry
   Average
   Wet
   Expected river conditions
 • No flow at Ricketts Marsh for six months
• Disconnected pools
 • No flow at Ricketts Marsh for four months
• Cease-to-flow events
 • Low flow at Ricketts Marsh for two months
• Low summer flow, high peaks in winter
 • High flow throughout winter with very high peaks; constant steady summer flow
 Expected availability of water for the environment
   • 1,000 ML
   • 1,300 ML
   • 1,500 ML
   • 2,500 ML
   Potential environmental watering – tier 1a (high priorities)
  • Summer/autumn low flow (east branch)
• Two summer / autumn freshes (east branch, reduced volumes)
  • Summer/autumn low flow (east branch)
• Two summer / autumn freshes (east branch, reduced volumes)
• Summer/autumn low flow (west branch, reduced volume)
  • Summer/autumn low flow (east branch)
• Two summer / autumn freshes (east branch, reduced volumes)
• Summer/autumn low flow (west branch, reduced volume)
  • Summer/autumn low flow (east branch)
• Two summer / autumn freshes (east branch, reduced volumes)
• Summer/autumn low flow (west branch, reduced volume)
   Potential environmental watering – tier 1b (high priorities with shortfall)
 • Summer/autumn low flow (west branch)
• Winter/spring low flow (east branch)
• Summer/autumn fresh (west branch, reduced volume)
• Winter/spring low flow (west branch)
  • Summer/autumn low flow (west branch)
• Winter/spring low flow (east branch)
• Summer/autumn fresh (west branch, reduced volume)
• Winter/spring low flow (west branch, reduced volume)
  • Summer/autumn low flow (west branch)
• Winter/spring low flow (east branch)
• Summer/autumn fresh (west branch, reduced volume)
• Winter/spring low flow (west branch, reduced volume)
  • Summer/autumn low flow (west branch)
• Winter/spring low flow (east branch)
• Summer/autumn fresh (west branch, reduced volume)
• Winter/spring low flow (west branch)
  Potential environmental watering – tier 2 (additional priorities)
 • There are no tier 2 watering demands because additional watering actions cannot be delivered within the existing infrastructure and flow constrictions
 Possible volume of environmental water required to achieve objectives
  • 250 ML (tier 1a)
• 18,200 ML (tier 1b)
  • 800 ML (tier 1a)
• 17,900 ML (tier 1b)
   • 1,000 ML (tier 1a)
• 17,700 ML (tier 1b)
   • 2,000 ML (tier 1a)
• 16,700 ML (tier 1b)
  Priority carryover requirements
   • Up to 250 ML
  • Up to 500 ML
   Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21 | 127
 


































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