To complete the configuration of a model alternative, you must assign a unique Model Alternative Key to each one. This key is an alphanumeric identifier that must be unique within a specific model, but can be reused across different models. For example, you might use N to represent “no future rain” in an HEC-MetVue model alternative and also use N for “normal conditions” in an HEC-HMS model alternative. However, you cannot assign N to two different HEC-MetVue model alternatives. These keys are required; you cannot build forecast alternatives with model alternatives that do not have them.

This guide will teach you how to assign keys to each model alternative in your HEC-RTS watershed.

Once assigned, a model alternative key cannot be changed. Choose your keys carefully.

To assign model alternative keys:

  1. Go the Setup tab.
  2. From to the Models menu, and select Model Alternative Keys.
  3. The Model Alternative Keys dialog will appear.
  4. From the Plugin dropdown list, select the model for which you want to assign a key.
  5. In the Key field, enter a unique alphanumeric identifier for the model alternative.
  6. Repeat Steps 4 and 5 for each model and its alternatives.
  7. Click OK to close the dialog.
  8. Save your watershed.