Page 301 - VEWH Seasonal Watering Plan 2020-21
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Scenario planning
Table 5.7.6 outlines the potential environmental watering and expected water use under a range of planning scenarios.
In 2020–21, delivering a spring fresh is a priority under all scenarios, to bolster the condition of the creek in the lead- up to summer. The spring fresh is planned to be delivered under drought and dry conditions using water that the VEWH will carry over from 2019–20. Under average and wet conditions, it is more likely that these flows will occur naturally.
The forecast water resource outlook indicates that the VEWH will not receive allocation in the Bullarook system during 2020–2021 under drought conditions. Under such conditions, the storage manager, Goulburn-Murray Water, will consult with water entitlement holders in the system to manage available resources with consideration of critical human and environmental needs. Under dry, average
and wet scenarios, full allocation is forecast. If available, allocated water is most likely to be used to deliver one to three autumn freshes between March and April 2021. If not required due to natural variation in the system meeting flow requirements, any unused water for the environment that was allocated on 1 December 2020 will likely be carried over to the 2021–22 water year, for use up to 30 November 2021.
Table 5.7.6 Potential environmental watering for Birchs Creek under a range of planning scenarios
5.7 Loddon system
 Planning scenario
 Expected river conditions
  • Reservoir spill unlikely
• Flows extremely low in winter/spring
• Limited irrigation releases due to low allocations
 • Reservoir spill possible
• Low flow in winter/ spring if no spills occur
• Moderate irrigation releases
 • Reservoir spills certain in winter/spring
• Some natural flow through summer/autumn
 Expected availability of water for the environment
  • 100 ML (carryover)
   • 100–200 ML (carryover and allocation)
   • 100 ML (allocation)1
   Potential environmental watering – tier 1a (high priorities)
  • One spring fresh
 • One spring fresh
• One to three summer/autumn freshes
 • One to three summer/autumn freshes
 Possible volume of environmental water required to achieve objectives
 • 100 ML (tier 1a)
   • 100–200 ML (tier 1a)
   • 100 ML (tier 1a)
  Priority carryover requirements
  • If the 100 ML allocation is received on 1 December 2020 and Birchs Creek is in good condition over summer/autumn, carry over 100 ML allocation into 2021–22 water year for use by 30 November 2021
  1 Under an average or wet scenario, it is likely that Newlyn Reservoir will spill before 30 November 2020, losing the 100 ML carryover from December 2019.
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