The USACE‑SWD models includes policy implemented as rules. Therefore, the model must use the Rulebased Simulation controller. The Rulebased Simulation controller is selected in the Run Control dialog.

A Rulebased Simulation model is an under determined model in terms of user input values. A set of prioritized rules, which implement basin policy, is used to look at the state of the system, execute policy logic, and set slot values to provide enough information for the model to solve.

In the calibration model discussed above, storage values may have been input for each timestep on every reservoir. The user may have chosen to input outflows or pool elevations instead. Regardless, in the rulebased model, this data must be removed because rules will be used to determine the reservoir outflows. However, this data will be useful for testing the various flood control algorithms so it should be stored on a data object. So for each reservoir object, copy input storage values into a custom slot and then clear those values from the reservoir object (every reservoir still needs an initial storage or pool elevation value so don’t remove those). Once these storages are removed, the model is under determined and will not solve. The flood control rules, whose implementation is discussed below, will be used to provide the necessary data for the model to solve.