As previously discussed, you can allow ResSim to use its implicit storage balance, or you can create an explicit system storage balance. In addition, the following notes related to system operations are provided:
When not identified in an explicit storage balance definition, maximum storage (100% full) is considered to be the maximum storage value in the elevation-storage table defining the pool of each reservoir.
Minimum storage (0% full) is considered to be the top of the Inactive zone unless the user has deleted the Inactive zone from the operation set, in which case, minimum storage of zero is used.
The Guide Curve does not have to be the top of the Conservation zone. The implicit balance scheme will recognize the specified guide curve at each reservoir when delineating the default balance lines.
For parallel reservoirs to operate as a system for a common downstream control point, the same common downstream control rule must exist at all of the parallel system reservoirs. The rule must be created at only one of the reservoirs. Once created, that rule will automatically be available in the list of existing rules for the other reservoirs. Then, to establish system operation, the downstream control rule can be added to the operation set at the other reservoirs via the "Use Existing" option in the Operations tab of the Reservoir Editor ("Using Existing Rules").
If the downstream control rules are created separately at each reservoir, even if the data entered into the rules is identical, system operation will not be invoked.
For tandem reservoirs, there can be an intermediate control point(s) for which the upstream reservoir operates.
System operation rules can be prioritized along with other rules in the operation set (i.e., depending on prioritization, they may be overridden).
Implicit and explicit storage balance schemes can be established among two or more reservoirs. When defining an explicit system balance, all reservoirs identified for parallel or tandem operation must be included in a single reservoir system (refer to "Selecting Reservoirs for the System"). For example, if you have three parallel reservoirs operating for a common downstream location, and only two of them are included in an explicit system storage balance, the explicit system storage balance will be ignored and the default implicit storage balance scheme will be used instead.
When one or more reservoirs are involved in both tandem and parallel system operation and you want to define an explicit storage balance between the parallel reservoirs, you should put all the participating reservoirs (both parallel and tandem) into a single reservoir system and the balance definition should address all the reservoirs in the system. For example, if you have two reservoirs operating in parallel for a common downstream location and one of the two reservoirs is part of a tandem system with an upstream reservoir, it is best to include all three reservoirs in the explicit reservoir system and associated system balance. Otherwise, if only the parallel reservoirs are included in the explicit system, and the tandem reservoirs are left to operate using the implicit system balance, then undesirable operations will result due to incompatibility between the implicit and explicit balance schemes.
The explicit system storage balance is defined using the Reservoir System Editor, as presented in the preceding sections of this section. To simulate the explicit system operation, the explicit system storage balance must be selected in the Alternative Editor's operations tab ("2024-05-08_16-54-19_Selecting a Reservoir System Storage Balance") along with the reservoir operation sets that contain the system operation rules.