Annual accounting is a custom assessment method for regulated water in resource assessment module. The general principles for an annual accounting system are:
- An available resource is calculated during a defined water year;
- Allocation of the resource is made to different account types;
- Each account type’s allocation are distributed between accounts linked to this account type; and
- Any allocated water that has not been carried over at the end of the defined water year will be returned to the available resource for allocations of next year.
An annual accounting system set up in Source follows these principles.
Enabling annual accounting
Firstly, create an annual accounting system as follows:
- Choose Edit » Resource Assessment... to open the Resource Assessment Explorer; and
- Right click Resource Assessment and choose Add Annual Accounting.
In the top Annual Accounting level, you can:
- Configure annual accounting using the Configuration tab;
- View summary information of all accounts added with the Accounts tab;
- Set the available resource vs allocation table using the Allocation tab; and
- Set trigger priority with the Trigger Priority tab.
The next sections provide further details of all the tabs listed above.
Configuring an annual accounting system
This tab provides an overview of the annual accounting system (as shown in Figure 1). The required parameters are explained in Table 1.
Figure 1. Annual Accounting, Configuration
Table 1. Annual accounting, Configuration tab
| Item | Description |
|---|---|
| Owner | This lists all the owners that have been configured using the Ownership Setup dialog (refer to Ownership in Source) |
| Debit Type | Determines how water is deducted from all accounts associated with this continuous accounting system; based on either order or extractions. |
| Start of Water Year | Day-month that the water year starts. |
| Usage to date | Represents how much of the water allocated has been ordered or used by water users in the water year to date. There are two options available - Usage From Function and Usage From Account Host. When losses need to be considered, an expression may be required to account for this. |
| Storages | Lists all the water storages in the project. Tick any storage you want to use. |
| Inflows | Lists all the inflow in the project. Just like the storages, tick any inflow you want to run in this project. The recession factor of each inflow can be changed using the corresponding Function Editor. |
| Other Resources | Represents inflows from tributaries or headwaters. |
| Commitments | These are used to represent for carryover, forecast losses, or reserves. Examples include the minimum storage level, or an environment carryover account. |
Accounts
This tab provides a summary of all the accounts in the annual accounting system. As shown in Figure 2, you can add or delete accounts using the corresponding buttons below the Accounts table. Each of the parameters in the Accounts table is explained in Table 2.
Figure 2. Annual Accounting, Accounts tab
Table 2. Annual accounting, Accounts tab
| Item | Description |
|---|---|
| Name | Name of the account. |
| Account host | Node that the account is associated with. |
| Account type | Type of account. This is configured under the hierarchical item Account Type. |
| Unit shares | Number of unit shares assigned to the account. |
| Initial balance | The initial account balance. If you are going to use the initial account function, you need to ensure that there is sufficient water in storages to cover the total initial balances as well as the required reserves and TOL balance. If the initial balances are set too high a warning message will be generated and the results may not follow the required logic. |
To add an account in the table, click Add Account below the Accounts table to open the Add New Account dialog (shown in Figure 3) and add an account in the table. The number of hosts available in a scenario will determine the number of accounts in an account type. To associate an account with a host, click on the individual account below the Account type. The section on the far right lists all the associated account hosts available in the scenario. Then, click on the required host.
Hosts in a scenario may consist of water users, bulk licensing nodes and the environmental demand node.
Figure 3. Annual accounting, Accounts tab, Add New Account
Allocation
The Allocation tab shows how resources are distributed, along with the proportion that is carried over. Configuration of the Resource and Rural columns depends on the how the Account type has been configured, in particular the Method to apply for this account type in ARA table parameter. Figure 4 shows how the ARA table varies with this parameter and Table 3 explains the variations.
The columns shown in the Figure 4 are:
- Resource - The water available in the system;
- Carryover - The proportion of water that is carried over to the next water year; and
- The last column is the Account Type, configured as shown in Figure 1.
Figure 4. Annual accounting, Allocation tab
Table 3. Annual accounting, Allocation, Variations
| Menu option in ARA table | Resulting variation in Allocation tab (Annual Accounting) |
|---|---|
| Percent (with linked volume) | The Account Type column can be edited directly on the table. The Resource column is calculated automatically based on the percentage. |
| Function | The Resource column is calculated based on the function specified at the Account or Account Type level (Table 5). Note that you must click OK to save and close the Resource Assessment Explorer for the Resource column to populate. |
| Monthly-varying | In the Account Type column, click the hyperlink to open the Monthly Varying ARA table showing the allocations for each month in the water year (shown in Figure 5). Depending on which option in chosen in the ARA table (Interpolate or Threshold) under Account Type, the value in the Resource column gets populated automatically. You can set the resource of each monthly manually or by import or export data using the corresponding buttons. If interpolate is chosen for calculation method, the Resource of the first column is calculated based on the current and next month values. If Threshold is chosen, the value in the Resource column corresponds to the value in the current month. |
| Percent (with function) | In the Account Type column, click Function... to specify what proportion of Shares (in the Account Type) will be assigned to the Resource column. For example, consider Shares = 50000, and the function specifies 10% in the Account Type column, the value in the Resource column will be 5000 (10%*50000). |
| Volumetric | The value is directly editable in the table. The Resource column then corresponds to the Account Type column. |
Trigger Priority
Figure 5 shows the Trigger Priority tab. Priorities are separated into two types based on Timestep Beginning and Timestep End. You can re-order the triggers to set the priority.
Figure 5. Annual accounting, Priority Trigger
The next section deals with how to configure the different items shown in Figure 1.
Adding an off-allocation system
Off-Allocation Systems are assigned at the top Annual Accounting level. To add an off-allocation system, right click Annual Accounting and choose Add Off-Allocation System. Refer to the Off Allocation node for more information.
Account Type
An annual accounting system may contain several account types. Each account type can also include many accounts. To add an account type, as shown in Figure 1, right click on the annual accounting system and choose Add Account Type.
In the Account Type level, you can use the:
- Configuration tab to configure the account type (shown in Figure 6);
- Accounts tab to view a summary of all accounts in the account type; and
- Non-Debit Accounts tab to view and configure all non-debit accounts in the account type.
The next section describes each of these tabs.
Configuring an account type
Figure 6 shows the configuration parameters required for an account type. These are explained further in Table 4.
Figure 6. Annual accounting, Account type, Configuration
Table 4. Annual Accounting, Account Type, Configuration
| Item | Description |
|---|---|
| Debit Type | Determines how water is deducted from all accounts associated with this continuous accounting system; based on either order or extractions. |
| Priority | A higher priority translates to resources being allocated prior to a lower priority user. |
| Minimum Balance | If a minimum balance is defined, then order or extractions will not be allowed if it will cause the balance to drop below the minimum specified. If choosing Unrestricted, also specify the Minimum Volume. |
| Maximum Balance | Defines the maximum volume of water which can be held in an account. If an allocation results in this limit being exceeded, then the excess amount is redistributed to other accounts. |
| Allocation Calculation | The default is Available Resource Allocation Table, which opens the ARA table. The options available for this are shown in Table 2. Choose Function to determine an account type's allocation using this method. This function may reference a wide range of variables available in the model, including allocations to other account types and resource assessment system. The Allow Decrease checkbox controls whether or not an account’s allocation can reduce within the water year. |
Table 5. Input parameters for the ARA Table options.
| Method | Input parameters |
|---|---|
| Function | Enter a function using the Function Editor. |
| Monthly varying | Choose the appropriate Calculation Method - either Interpolate or Threshold. |
| Percent (with function) | Configure the following parameters:
|
| Percent (with linked volume) - default | Same parameters as Percent (with function). |
| Volumetric | None. |
Accounts
Choose the Accounts tab to view a summary of all the accounts configured in the account type. The Accounts table is similar to that shown in Figure 2, with parameters summarised in Table 2.
Non-debit accounts
This tab allows you to work with Non-debit accounts. Enable the Enable Non-Debit Accounts checkbox, which allows you to edit the remaining parameters (as shown in Figure 7). These are:
- Availability Threshold - The allocation level at which the water user gets access to the account;
- Repayment Threshold - The allocation level at which repayments need to be made. As the water user approaches its maximum allocation, repayments need to be made;
- Carry-Over Discount - A discount implemented on the water that is carried over to the following water year. Note that this applies only when Murrumbidgee is chosen as the Balance Calc Method; and
- Balance Calc Method - choose either Murray or Murrumbidgee. This will affect the value assigned to the first two parameters.
Figure 7. Annual accounting, Account type, Non-Debit Accounts
Once an account type has been created, you can create the following using the contextual menu (as shown in Figure 1):
- Accounts
- Triggers; and
- Usage limits
These are explained in further detail next.
Adding an account to an account type
To add an account to an account type, you must configure Number of Shares, the Initial Account Balance and Previous Usage parameters (as shown on the left side of Figure 7). To link the account to a host, choose the water user under Associated Account Host. The associated account lists all the water user nodes in the project. Once these have been configured, you will notice that the value configured for the Number of Shares relates to the Demand distribution item of the water user node (shown on the right side of Figure 7). Refer to Demand distribution for details on configuring the water user node. Notice also that the Account Distribution table (in the node's feature editor) shows details of the resource assessment system.
Figure 7. Annual accounting, Account type, Add account
Adding a trigger to an account type
Triggers are used to initiate or cancel certain actions for an account and can be added at any level in annual accounting. To add a trigger, right click on the account type and choose Add trigger. You can rename or delete an existing trigger by right clicking the trigger and choosing the appropriate contextual menu option.
As shown in Figure 8, configure the following parameters under Trigger Configuration:
- Trigger - the type of trigger. For example, to trigger an action using a function, choose Function in the Trigger drop-down menu. The format of a function should be like this: “IF A>B, 1, 0”, where “1” indicates the action will occur and “0” means the action will not happen; and
- Execution - when to execute the trigger (ether at the beginning or end of the time-step.
The resulting Action Configuration panel will change depending on what is chosen under Trigger Configuration.
Once triggers are configured, you can prioritise them using the Trigger Priority tab (Figure 5).
Figure 8. Annual accounting, Account type, Trigger
Adding a usage limit to an account type
Right click the account or account type and choose Add usage limit. The GUI is similar for that in Continuous Accounting (here). You can limit water usage for all accounts by absolute volume or per-unit-share for moving water year or movable time window. An account can have several usage limits, each can be designed to initiate a particular limit. Just like triggers, you can rename or delete usage limits.
