As stream alignments, map layers, and data are added to a project, the files and directories listed in Table: Example HEC-FIA Directories and Files are created, along with automatic backup files. One case of this is a NB_project.prj file and a NB_project.prj.bak file are created when the project is created. For example, when a map layer is added to a map window, the *bak file of the project's *prj file (where map window properties are stored) would not have any reference to the added map layer, since the backup file reflects the state previous to the current changes. So every time the user Save's a project, the *bak file is updated to the previous state of the file being saved, and edits are saved in the *prj file.
Automatic backup files are created for all project, alternative, simulation, and results files. It is important to note that HEC-DSS files are not automatically backed up. Since the *.bak file reflects the previous state of that file, the user can go back to the previous state by eliminating the actual file, and deleting the *.bak extension of the backup file (this should be done while the HEC-FIA project is closed). This procedure would allow the information for that previous state (recorded in the backup file) to become the current state.
The overall effect of the procedure above would be "undoing" all changes the user made in the last cycle even if the changes have been saved or automatically saved. One should note, as soon as the HEC-FIA project is re-opened, the model files are all "backed up" so the *.bak file is automatically updated. Therefore, if the user wants to eliminate saved changes, deletion of the *.bak file must occur before re-opening the project.
Important: If the HEC-FIA project was created in HEC-FIA Version 3.0.1 (and older) then the project will not be able to be opened directly in HEC-FIA 3.3. The project should first be opened in HEC-FIA 3.2 and then subsequently opened in HEC-FIA 3.3.