There are two types of scenarios:

• Base Scenarios—Contain all of your working data. When you start a new hydraulic model, you begin with a default base scenario. As you enter data and calculate your model, you are working with this default base scenario and the alternatives it references.
• Child Scenarios—Inherit data from a base scenario or other child scenarios. Child scenarios allow you to freely change data for one or more elements in your system. Child scenarios can reflect some or all of the values contained in their parent. This is a very powerful concept, giving you the ability to make changes in a parent scenario that will trickle down through child scenarios, while also giving you the ability to override values for some or all of the elements in child scenarios.