Annual accounting is a custom assessment method for regulated water in the resource assessment module. The related water user, bulk licensing or environmental demand nodes must be configured consistently with the resource assessment system. The general principles for an annual accounting system are:
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| Note: The Method to apply for this account type in ARA table drop-down menu has several options available (as shown in Figure 6), each with a different set of input parameters, explained in Table 6. The option chosen here affects the view in the Allocation tab for the annual accounting system (Figure 4), and are described in TABLE Y |
Table 6. Input parameters for the ARA Table options.
| Method | Input parameters |
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| 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:
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| Percent (with linked volume) - default | Same parameters as Percent (with function). |
| Volumetric | Volume. |
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This tab allows you to configure several parameters related to carryover, such as spill and its associated parameters (Figure 7). Spill is water released in excesss of the downstream requirements. Table 7 explains the configuration parameters.
Figure 7. Annual accounting, Account type, Carryover
Table 7. Annual accounting, Carryover parameters
| Item | Description |
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| Max Carryover | This is the maximum amount of water that can be carried over. It can be defined in terms of:
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| Maximum Effective Allocation | The maximum amount of water that an account can hold, including allocation and carryover. If enabled, you must define effective allocation in the Limit field. For example, if you specify 130%, allocation plus carryover water cannot exceed 130% of the entitlement. The carryover is not reduced; the allocation is restricted, preventing allocation plus carryover from exceeding 130% of entitlement. |
| Carryover Type | Select the type of carryover to configure using the drop-down menu:
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| Do Not Carry Over Spillable Water | If enabled, spillable water will not be available for carryover. If disabled, any remaining spillable water will be carried over to the next water year. |
| Spillable Volume Calculation Method | Spillable water is calculated using one of two methods:
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| Spillable | Allows you to trigger the account to spill. You can specify a boolean function to switch account spilling on or off. |
| Basis of Spilling | There are three options available:
If different account types under the same spill source have the same priority, then the priority of spilling from account types with Emptied on Spill or Pre-Release first, followed by Equalise Spillable Carryover Proportions and Reduce pro-rata last. |
| Water Available While Spillable |
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| Spill Reduction Priority | The priority of spill from the carryover account. The default value is 1, which is the highest priority. 2 is the next highest priority, then 3 and so on. During a spill, all accounts of the same priority are grouped together and the spill volume is distributed among these accounts pro rata. Any remaining spill is then passed along to the next priority grouping. |
| Use Account Type Spill Volume | When enabled, allows you to specify a value for Account Type Spill Volume. This volume will be used instead of the Spill Volume set at the top Annual Accounting System level (set on the Configuration tab, see Table 1.) |
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This tab allows you to work with non-debit accounts. First enable the Enable Non-Debit Accounts checkbox., which allows you to edit the remaining parameters (Figure 8). Parameters are explained in Table YY.
Figure 8. Annual accounting, Account type, Non-Debit Accounts
Table YY. Annual accounting, Account type, Non-Debit Accounts
| Item | Description |
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| Enable Non-Debit Accounts | Toggle on to edit the other parameters in this tab. |
| Use Per Share Upper Limit | ?? |
| 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. |
| Carryover 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 Calculation Method. |
| Balance Calculation Method | Choose either Murray or Murrumbidgee. This will affect the value assigned to the first two parameters.?? |
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Figure 9. Annual accounting, Account type, Add account
Table 8. Annual accounting, Account type, Account parameters
| Item | Description |
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| Entitlement | Entitlement volume assigned to the account. |
| Initial Allocation | Allocation on the first day of the model run. |
| Initial Account Balance | As its name suggests, this is the initial account balance of the system (corresponds to Initial Balance in Figure 2 and Figure 3). |
| Initial Carryover Scalar | Used to reduce the carryover commitment. The product of the carryover scalar and carryover start of water year is the carryover commitment at the start of the model run for the account. The carryover scalar is reset to 0 at the beginning of each water year, and increased as resources allow the commitment to be met (in accordance with the ARA table). |
| Carryover Start of Water Year | The amount of water carried over from the water year prior to the water year that the run commences in. |
| Previous Usage | The amount of usage between the start of the water year that the run commences in, and the first day of the model run. |
| Previous Spill from CarryOver | The amount of spill reduction from the carryover account between the start of the water year that the run commences in, and the first day of the model run. This is zero if the model run commences on the first day of the water year. |
| Associated Account Host | This lists all available account hosts in the model. Account hosts can be water user, bulk licensing or environmental demand nodes. To associate an account host with this account select it from the list. A host can only be associated with one account per account type, so a host that already has an associated account will not appear in the list. Once these have been configured, this association is reflected in the host node's feature editor, which can be used to configure the distribution between associated accounts and carryovers, as follows:
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| Note: Each account can have only one host associated with it. Each host can only have one associated account per account type. |
Triggers
Triggers specify events that affect the behaviour of the annual accounting system, such as allowing you to reassess accounts during the water year, or cancel XXX. Triggers can be added to an annual accounting system, an account type or an account. To add a trigger, right-click on the component and choose Add Trigger. This will create the trigger and display the dialog where you can define and configure it, see Types of triggers. Once you have created triggers, you can configure their priority using the Trigger Priority tab for the annual accounting system, see Trigger Priority.
Usage limit
Accounts and account types may have limitations placed on their usage that are independent of their allocation (or account balance). This dichotomy may occur because the allocation relates to a water year, and the usage limitation relates to multiple years or a moving time period.
Usage limits can be added to an account type or an account. To add a usage limit, right-click on the component and choose Add usage limit, then configure the usage limit using the dialog (Figure 9, Table DD). An account can have several usage limits, each can be designed to initiate a particular limit.
Figure 9. Annual Accounting, Usage limit
Table DD. Annual Accounting, Usage limit parameters
Item | Description |
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| Period | Time period that the limit applies to - Moving Water Year, Moving Window or Water Year. If a usage limits relates to a single water year, choose Moving Water Year and set Years to 1. Where a "rolling years" usage limit has been defined in IQQM for general security accounts, these should be defined as Moving Water Year limits as Moving Water Year limits in Source. |
| Quantity | Specify if the limit is Proportion of Entitlement or an Absolute VolumeAbsolute Volume. To replicate IQQM, set this parameter to Volume per Unit Shareto Proportion of Entitlement. |
| Years | For a moving water year, enter the number of years the usage limit applies to. For a moving window, define the number of days and time units (eg. days) that the usage limit applies to. |
| Quantity | Usage limit over the period that is to be applied to all accounts, as either Proportion of Entitlement or Absolute Volume. |
Annual accounting system configuration
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| Item | Description |
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| Start of Water Year | Day-month that the water year starts. If unspecified, it defaults to 1st July. |
| Owner | This lists all the owners that have been configured using the Ownership Setup dialog (refer to Ownership in Source). |
| Usage to date | Determines how much of the water allocated has been ordered or used by water users in the water year to date. There are three options available:
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| Spill Volume | In cases where the available water is in excess of the volume ordered by entitlement holders, the extra volume is referred to as Spill Volume. This is usually defined as a function. |
| Usage Amount | Only applicable when Usage to date is assigned Usage from Function, enter a function or value for the usage amount. |
| Storages | Lists all the storages in the scenario. Enable a storage by toggling on the check box to use it as a resource in the annual accounting system. For each enabled storage, you may specify the Evaporation Pattern and Minimum Inflow as a monthly pattern. Note that net evaporation can be negative. At assessment date, the available storage volume is reduced by the net evaporation volume to end of season and may be increased by the inflow volume to end of season (if Use inflow for resource is enabled). These monthly volumes are appropriately proportioned when assessment/end of season dates are not at start/end of month. Enable Use Inflow for Resource to add the sum of the inflows to the end of the water year to the current storage volume. Enable Use Inflow for Evaporation to add the sum of inflows to the end of the water year to the current storage volume before determining surface area to calculate volume of evaporation. If neither Use Inflow for Resource nor Use Inflow for Evaporation is enabled, even if there is a Minimum Inflow monthly pattern defined, it will not be used in calculations. |
| Inflows | Lists all the inflows in the project. Enable any inflow to use it as a resource for the annual accounting system. The recession factor of each inflow can be set either as a constant value or as a function. Source multiplies the downstream flow volume for the selected inflow node by the recession factor to calculate the volume of water available as a resource. |
| Other Resources | Represents other resources such as inter-valley transfers. To add another resource, click on the cell under Name and enter a name, then click on Function... under Resources to enter a value or define a function to represent that resource. |
| Commitments | These are used to represent other commitments such as special reserves or provision for minimum flows. Commitments are added the same way as Other Resources, see above. |
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