Document History
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- The start of the off allocation water year,
- Whether the sharing arrangement is on the basis of trying to equalise access opportunity to account holders, however, the Equalise Shares function is no longer accessed by the user since version V4.10.2 of Source.
- Optional annual system cap on the amount of off allocation water that can be allocated in a water year,
- Optional rules for resetting account balances when specified storages spill,
- Configurable list of storages that are considered for off allocation access, and
- Off allocation accounts.
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Using a matrix to solve the owner's share:
Equalise shares of off-allocation water
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Allocate off-allocation water to accounts based on shares
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Each OAN processes the orders for its direct users downstream (including the next downstream OAN) and passes the combined orders up to the next OAN (if there is one). This means that it is possible to share off allocation water between multiple downstream reaches.
In the example illustrated in Figure 6, below, OAN3 has a share component in OAN2 which also has a share component in OAN1. This means that the off-allocation requirements of water user 3 and 4 are accumulated up the system and are reported as the off-allocation requirement of OAN2. This means that the allocation of off-allocation water to reach 1 takes into consideration the downstream requirements. It is possible to give priority access to downstream requirements by assigning the highest priority to OAN2 in the OAN1 allocation table.
Note that while OAN1 assigns a volume of off-allocation water to OAN2, the processing of OAN2 may result in a change in the volume of off-allocation water available to that reach as the rules specific to OAN2 are used to calculate the available water. 
Figure 6 — Example of multiple off allocation reaches
Off allocation and storages
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