CWMS (Corps Water Management System) or an HEC-RTS watershed has been built for forecasting in the same watershed area that a PDT wants to build an HEC-WAT study. The HEC-WAT software has the capability to import a CWMS/HEC-RTS watershed. Once the import is finished, the study team will need to review the models and make adjustments as needed. The first step is to create a basic HEC-WAT study, in Chapter 7, Section 7.1, follow those steps to create a new HEC-WAT study
To import a CWMS/HEC-RTS watershed:
1. From the HEC-WAT main window (Figure 8.1), from the File menu, point to Import, click CWMS Watershed. The Import CWMS Watershed dialog box will open (Figure 8.16).

Figure 8.16 Import CWMS Watershed Dialog Box
2. Now select the CWMS/HEC-RTS watershed, from the CWMS Watershed File box, click , and the Select Workspace File browser (Figure 8.17) will open. Browse to the directory where the CWMS/HEC-RTS watershed is located and select the CWMS/HEC-RTS watershed file (.wtrshd). The watershed filename will appear in the *File name box (Figure 8.17), click Import, the Select Workspace File browser will close (Figure 8.17).
3.A Continue Import? window will open (Figure 8.18). This window is warning the user that the import process will overwrite any existing data in the HEC-WAT study. Click Yes, the Continue Import? window will close (Figure 8.18)

Figure 8.17 Select Workspace File Browser

Figure 8.18 Continue Import? Window
4.The Import CWMS Watershed dialog box (Figure 8.19) will now display the name of the CWMS/HEC-RTS watershed file in the CWMS Watershed File box (Figure 8.19). As the import proceeds, the Import Progress box on the Import CWMS Watershed dialog box (Figure 8.10) will display what is happening during the import. The table on the Import CWMS Watershed dialog box (Figure 8.19) will display which CWMS/HEC-RTS watershed components have finished, whether the import was successful or not, and the number of model alternatives that were imported.
5. When the HEC-WAT study is created an hms subfolder is created. In that subfolder are the default files that are generated when creating an HEC-HMS project. When the HEC-HMS import process finds that a project already exists, a warning window will appear (Figure 8.8; this warning window can open behind the HEC-WAT main window). Click Yes, the warning window will close.
6.If the HEC-HMS model was created using a previous version of HEC-HMS, a Convert HEC-HMS Project window (Figure 8.9) will open. This window is letting the user know that the HEC-HMS model will be converted to a Version 4.2.1 HEC-HMS model. Click Convert Project, the Convert HEC-HMS Project window (Figure 8.9) will close, and the import of the watershed will continue.

7.Once the import process is finished from the Import CWMS Watershed dialog box (Figure 8.19) click Close. The Import CWMS Watershed dialog box (Figure 8.19) will close, and the HEC-WAT main window (Figure 8.20) will display the map layers and the stream alignment of the imported CWMS/HEC-RTS watershed.

Figure 8.19 Importing CWMS Watershed Dialog Box
8.The CWMS/HEC-RTS watershed has been imported into an HEC-WAT study. From the HEC-WAT main window (Figure 8.20), from the File menu, click Save.


Figure 8.20 HEC-WAT Main Window after a CWMS/HEC-RTS Import