Problem Description

When computing a model, the following user notification is generated, referencing a composite outlet structure: The cross section maximum elevation xxx.xxx ft is above the maximum headwater elevation xxx.xxx ft.

Steps to Resolve

The likely cause of this issue is the elevations entered for the cross section of an irregular weir in the composite outlet structure. The elevations for the cross section are relative to the headwater . For instance, if the maximum headwater elevation is set at 318 ft and the first station of the cross section is also listed as 318 ft, the cross section maximum elevation used in the program will be 638 ft.

The solution for this would be change the cross section elevations to make them relative to the headwater elevation. The simplest method for doing this would be to subtract the headwater elevation value from the elevation of the cross section in the "Irregular weir cross section" collection table. Open the table and right-click on the column "Elevation". Choose Global Edit and change the Operation field to "Subtract". Set the Value field to the maximum headwater elevation. When you click Okay, the values will automatically change. When you compute, this user notification should not occur.