If you define a culvert with a zero upstream distance the program returns an error message that this is not allowed in the current version, and that a distance >0 is required. After inputting an upstream distance in the culvert definition window, the distance is reflected in the data but the program continues to return the error message.
Causes: The Deck/Roadway Distance value cannot be zero for a bridge in HEC-RAS.
1. Go to Bridge & Culvert pull down.
2. Select Roadway Overflow (Roadway/Deck Data Editor in HEC-RAS).
3. Define a non-zero value for "Bridge rail to section distance" and Click OK.
4. Save the model and Compute the model.
Products: AutoCAD Civil 3D