Water ownership deals with the assignment and tracking of water as it is stored in, transits through, and exits regulated river systems. This is an important aspect of water management, as it allows resource sharing amongst owners in a sustainable and traceable manner, whilst at the same time, providing the ability to determine how much water an owner has, and where it is located. The introduction of ownership in a system means that water can be traded, both within storages as well as in transit. Additionally, separate resource allocation systems can be developed for owners, allowing for the modelling of capacity sharing, and continuous sharing in water allocation systems.

Water ownership is assigned and reassigned at nodes, while it is accounted for in river routing links and storage links. Note that the river modelling framework considers storages as links, but in the schematic builder, storages are displayed as nodes. Water may also be reassigned (ceded) in storages.

Ownership in Source

Ownership is specific to a scenario and you must configure it individually for each model. The following nodes provide a means of assigning ownership to a model:

• Confluence;
• Supply-point;
• Inflow;
• Maximum Order Constraint;
• Minimum Flow Requirement;
• Splitter (loss, distributary and anabranch);
• Storage;
• Transfer Ownership; and
• Water User demand nodes (includes town water supply, time series of demand, crop soil moisture water models and environmental demand).

Each node has different ownership characteristics and will manage ownership in its own way. These are discussed later.

Prerequisites

Prerequisites for using ownership in Source include:

• Building the schematic for the network model;
• Defining water sources; and
• Defining owners and their demands. There are three types of owners available (listed in Table 58). Note that Unassigned_Water is not editable.

Once these criteria are met, enable ownership. This is described next.To enable ownership:

Enabling ownership

• Choose Edit > Ownership... to open the Ownership Setup window (Figure 95);
• ...

Ownership at nodes

Once you have enabled ownership, you can configure it at various nodes using each node’s feature editor. The is described next.

Inflow

To configure ownership in the inflow node, select Ownership in the node’s feature editor (Feature Editor 78) and specify each owner’s proportion of water. You can also import and export ownership data. Ensure that the total proportion of water is always 100%.

Storage

Ownership at the Storage node can be configured in the following tabs. The result for each tab varies depending on what is required from the model:

• Owner shares;
• Spill Ownership;
• Internal Spilling and Ceding; and
• Outlet Path Constraints.

Owner Shares tab

The Owner Shares tab (Feature Editor 79) allows you to specify each owner’s share of water capacity (%) and water volume (ML) in the storage node. Note that initially, Unassigned_Water has a 100% allocation, which decreases as other owners are assigned water.

There are three values specified for each owner: Capacity (%), Volumetric Capacity (ML) and Initial Volume. These can be entered manually or imported from an external source. You can also allocate capacity and volume evenly amongst users using the button below Import and Export.

Spill Ownership tab

This functionality is yet to be documented. If you would like assistance, please call 1300-5-WATER (1300-592-837) (refer to Feature Editor 80)

Internal Spilling and Ceding tab

Specify the distribution rule under ‘Internal Spilling’ and the ceding owner under "Ceding" (Feature Editor 81).

Outlet Path Constraints

This functionality is yet to be documented. If you would like assistance, please call 1300-5-WATER (1300-592-837) (refer to Feature Editor 82)

Transfer Ownership

The transfer ownership node (Feature Editor 83) allows for transfers to be scheduled according to the specified distribution rules. The data required includes:

• Start Date - first day of transfer.
• End date - last day of transfer.
• Transfer rate - rate of transfer in ML per day.
• Transfer at constant rate above inflow rate of X ML/day. When inflow rate of X ML/day is reached, transfer at a constant rate of X ML/day.
• Transfer all excess above inflow rate of X ML/day. When inflow rate of X ML/day is reached, transfer all the excess water.
• Distribution rules - transfer in accordance with this Distribution rule.

Import and export functions are available in this tab.

Maximum Order Constraint

The Owner Shares tab in the Maximum Order Constraint node (Feature Editor 84) allows owners to share the constraint at individually set rates if required. The individual parameters are:

• Owner - owner’s name.
• Proportional share of constraint (%) - percentage of the constraint to be shared by this owner.
• Rate share of Constraint (ML/day) - constraint rate to be shared by this owner.
• Excess capacity Distribution rule - distribution rule to follow when maximum capacity of water has been reached by this owner.

Import and export functions are available in this tab.

Minimum Flow Requirement

The Ownership tab in the Minimum Flow Requirement node (Feature Editor 85) allows owners to share the constraint at individually set rates, if required.

Loss

Open the feature editor and click the Ownership tab (Feature Editor 87) and choose the ownership method with the pull down menu at the top of the tab.

The loss node offers two methods for determining ownership of losses:

• Distribute flows with these proportions - use the table shown in Feature Editor 87; and
• Distribute flows according to owned amounts - no input required.

Controlled Splitter

Ownership information is required at splitter nodes to determine the proportion of each owner’s water to be directed to each outlet. Ownership of unallocated flows from a splitter can be distributed according to owned amounts or by selecting different proportions to the owned amounts. The method can be selected from the Method for attributing ownership of unallocated flows from effluent pull-down menu on the Ownership tab. An owner may have all water directed through one splitter outlet, or in any proportions required. An owner’s total water may not exceed 100%. Import and export functions are available in this tab.

Controlled Splitter

Ownership at the Controlled splitter node functions in the same way as it does at the Splitter node.

Distribute flows by owned amounts

Selecting Distribute flows according to owned amounts requires no additional parameters (Feature Editor 88 and Feature Editor 89).

Distribute flows by proportion

Selecting "Distribute flows with these proportions" displays the parameters shown in Feature Editor 90 and Feature Editor 91. The Assign Proportions checkbox enables an upstream flow threshold to be specified which will activate the distribution if flow falls below that threshold.

The proportion allocation panel allows for manual entry of distribution amounts. Alternatively, the proportions can be imported from a .CSV file formatted as shown in Table 59. The same format is used for both the Splitter and Controlled Splitter nodes.

Where: owner is the name of the owner or the sentinel value "Unassigned Water"
link is the name of the effluent link (this column title is ignored on import)
prop is the proportion allocated to this owner, expressed as a percentage (eg "10" for 10%)