Many regulated river systems support several resource assessment schemes to share the available resource (water) amongst users. In Source, a resource assessment system:

• is associated with only one scenario in a project, whereas a scenario may be associated with one or more resource assessment systems;
• can only have one owner, but any given owner or water user may be affected by more than one system; and
• supports multiple account types.

Note that resource assessment only operates correctly in a regulated system.

#anchor-24-anchor shows the various contextual menus available for each level in the resource assessment hierarchy. Note that similar types of accounts or systems have the same contextual menu. For example, all off-allocation systems have the same contextual menu, and all account types follow a similar trend.

In practice there are a number of resource assessment methodologies used, which can be implemented in Source using a generic resource assessment tool, referred to as Simple Water Accounting. The next section provides details on configuring two types of resource assessment in Source - general and continuous sharing.

General Resource Assessment

To enable General Resource Assessment:

• Choose Edit > Resource Assessment... from the Source main menu;
• Click + to the left of the project name (Figure 84) to reveal the project’s active scenarios; and
• Right-click the scenario for which you wish to enable resource assessment and choose Add Simple System from the contextual menu (Figure 84).

You can edit the system name by right clicking on the name and choosing Rename from the contextual menu. Type in the field and press the carriage-return.

Once a system has been added (Figure 85), provide the following details:

• Set the system Owner. There can only be one owner per system; and
• Set the Water Year Start date. The system will run for 365 days from the date set.

You can also configure an off-allocation system and an account type by right-clicking the system name and choosing from the contextual menu.

Adding an account type

A system may contain several account types, each consisting of many accounts that have common properties. With resource assessment, you can group accounts according to different levels of water security, or any other common criteria appropriate to a set of accounts.

To add a new account type, right-click the system name and choose Add Account Type (Figure 85). If desired, you can edit the account type name to be more meaningful.

When an account type is selected, the right hand panel displays two tabs - Details and Allocation. The former (shown in Figure 86) is a summary of operating information for each account type, whereas the latter (shown in Figure 87) calculates account allocations using either a time series, expression or results from another scenario.

Note that allocation data is interpreted as a cumulative volume allocated per unit share. This means that accounts are only credited if there is an increase in allocation volume since the previous timestep. An account is credited by calculating the increased volume multiplied by the number of shares that the account has in the resource assessment system.

The Originating Allocation System item in the Details tab is a feature relating to tagged trading. In the current version of Source, this functionality is not available.

Adding an account

In the Resource Assessment Explorer window (shown in Figure 87), right-click on the Account Type in the left hand panel and choose Add Account from the contextual menu.

You can configure the properties of an account using the panel displayed in Figure 88. Note that:

• Each account can have only one water user associated with it;
• You must enter the number of shares that the account has in the resource assessment system; and
• You can specify an opening account balance.

Account type triggers

A trigger initiates or cancels certain actions for an account type and can be configured using the properties panel shown in Figure 90. To set up a trigger, right-click the account type on the left hand panel and choose Add trigger.

Triggers can be set to activate on a particular date, a year start or end or the passing (either raising or falling) through a specified storage water level. When a trigger is activated it will initiate a pre-defined action, which is defined in the panel on the right hand side of the Triggers window. Possible actions include:

• Transferring a percentage of water to another account;
• Levelling accounts;
• Writing off accounts; and
• Truncating or assigning accounts.

An account type can have several triggers, each designed to initiate a particular action. Triggers can be prioritised by moving them up or down under Trigger Precedence.

Usage limits

You can limit water usage for all accounts by absolute volume or a per-unit-share, which can cover a water year or movable time window (shown in Figure 89). You can define any number of usage limits.

• To add a usage limit, right click on Account Type and choose Add Usage Limit;
• To delete a usage limit, right click on it, and choose Delete; and
• You can also rename it using the contextual menu.

Note that the usage limit, regardless of its position in the hierarchy, requires the same parameters to be configured. Figure 89 is therefore the same for all invocations of usage limit.

Continuous Sharing Resource Assessment

A Continuous Sharing Resource Assessment System is one in which the behaviour of a water user has as little effect as possible on other water users within that system. To enable it in Source:

• Choose Edit > Resource Assessment...;
• Click + to the left of the project name (Figure 84) to reveal the project’s active scenarios; and
• Right-click the scenario for which you wish to enable resource assessment and choose Add Continuous Sharing from the contextual menu (Figure 84).

You can rename the system using the same method for simple resource assessment systems. Refer to General Resource Assessment.

System Configuration

To configure a continuous sharing system, start by selecting the owner whose share is described by this system from the Owner pop-up menu (Figure 91) and define the start of the owner’s water year. The owner may be any one of the defined owners in the physical system being modelled. The other owners are assumed to use separate allocation systems, with all calculations occurring independently.

Note At present, ownership is not guaranteed to be fully functional and should be used with care. Unless you have a specific need, use the default owner, Unassigned Water, for all allocation systems.

The sharing of various system losses is based on long term averages. Over time, discrepancies will emerge which must be reconciled. You can control the frequency with which reconciliations occur using the Timesteps per Reconciliation field. The default is one time-step. Shortfalls identified during a reconciliation are treated as storage losses, gains as inflows. Losses and gains are shared equally and ignore account priorities.

The reconciliation process also resolves situations such as when multiple resource assessment systems draw upon the same water (whether such a configuration is accidental or deliberate).

The second step is to specify the percentage shares that the owner has in each storage known to the system. You use the Owner Shares tab in the relevant Storage feature editors to accomplish this.

Next, select each storage that should participate in the continuous sharing system in the Unassigned Storages list and move it into the Assigned Storages list by clicking the button with the right arrow. Note that a storage can be removed from the Assigned Storages list by selecting the storage and clicking the button with the left arrow.

As each storage is added to the Assigned Storages list, the owner’s share in that storage is added to the Total Conceptual Storage field, which is the sum of the active capacity for this owner of all of the assigned storages in the resource allocation system. You can not edit this value directly.

By default, 100% of all allocations are considered to be high priority but you can designate a lesser proportion by adjusting the High Priority Allocation field. The related fields of High Priority Storage, Medium Priority Allocation and Medium Priority Storage adjust dynamically in response.

You can adjust the Medium Priority Threshold field to determine how inflows are assigned to accounts. The field behaves as follows:

• When storage is below the stipulated threshold, inflows are only assigned to high priority accounts; and
• When storage is at or above the stipulated level, inflows are assigned to both high priority and medium priority accounts according to the percentages entered in the respective priority allocation fields.

The default Medium Priority Threshold is zero which means that inflows will be assigned to both high priority and medium priority accounts.

The System Cap Balance Carryover specifies the maximum proportion of the owner’s annual resource cap that the system can carry over into the next water year.

Finally, you can define the loss characteristics of each storage in millimetres per day between one or more start- and end-date pairs within the water year. You can also import loss characteristics from a .CSV file formatted as shown in Table 57.

Adding Accounts

To add accounts to a continuous sharing resource assessment system, switch to the Accounts tab (Figure 92) and click Add Accounts to open the Add Accounts window (Figure 93). The nodes which appear in the list on the left hand side of Figure 93 are Water User nodes, otherwise known collectively as demand nodes. Select one of the nodes in this list and click OK.

To add accounts for more than one demand node to a resource assessment system, repeat the process of clicking Add Accounts, selecting the relevant demand node, and clicking OK.

Accounts are always added in pairs. Each demand node always has one high priority account plus one medium priority account. Note that, where the High Priority Allocation is 100% (Figure 91), the medium priority account will remain unused.

You can delete an account-pair by selecting either of its members and clicking Delete Accounts.

Account configuration

You can configure individual accounts by manipulating the controls shown in Figure 92. Fields that are grey can not be adjusted. They fall into three categories:

• Values that are inherited from previous steps and which are included for reference. Examples include the Name, Type and Priority fields;
• Values that are set by reference to other values. The Maximum Balance column is an example; or
• Fields that must first be enabled explicitly. For example, you must enable the relevant Spec Cap checkbox before you can specify an Annual Cap.

You can allocate shares water by shares or volume. You can also specify a maximum cap (Max Cap) for an account by entering a capacity limit in megalitres. A value of zero means no cap is enforced.

The share factor (Share Fact) defines the relationship between orders and the amount that must be released in response to those orders, having regard to losses and gains during transmission:

• A share factor in the range 0.0 < Share Fact < 1.0 indicates that a loss is expected to occur between the storage and supply point. The closer to zero, the greater the loss;
• A share factor of 1.0 indicates perfect transmission between the storage and supply point; and
• A share factor greater than 1.0 indicates gains are expected to occur during transmission, such as inflows from a tributary.

All share factors at a given priority level within a continuous sharing system are interrelated as follows:

Unless overridden, subsequent calculations, such as the maximum balance, inflow share and annual cap are based upon that ratio.

Removing components

You can remove components from the Resource Assessment Explorer hierarchy by right-clicking on the entry you want to remove, then choosing Delete from the contextual menu. You can only remove components that you added. You can not remove project or scenario components.

Where: flux is the loss in millimetres per day for the recurrent period defined by start through end
start is the first day of each year represented as dd-mmm (eg "01-Jan") on which flux begins
end is the last day of each year represented as dd-mmm (eg "01-Jan") when flux ends.