To create a new watershed:

      1. From the HEC-RTS main window (Figure 5.1), from the Setup module, from the File menu, click New Watershed. The Create New Watershed dialog box (Figure 5.2) will open.


Figure 5.1 HEC-RTS Main Window – Setup Module

      1. Enter a name for the watershed in the Watershed Name box (Figure 5.2). Optionally, the user can enter a description of the watershed in the Description box (Figure 5.2), enter a description for the new watershed.


      1. From the Watershed Location list (Figure 5.2), select a watershed location that has been created (Section 3.2).


      1. The default unit system is English, from the Unit System list (Figure 5.2) the other choice is SI (metric).



Figure 5.2 Create New Watershed Dialog Box

      1. The user can add background shapefiles at this time by clicking Add Map Layers (Figure 5.2), the Select Map to Add browser will open (Figure 5.3). From the browser the user will navigate to where the background shapefiles for the watershed are located, select the shapefile, click Open, the Select Map to Add browser will close (Figure 5.3). The user can also add map layers to the watershed after the initial setup of the watershed (Section 5.2).


Figure 5.3 Select Map to Add Browser

      1. Next, the projected coordinate system of the watershed needs to be set. From the Create New Watershed dialog box (Figure 5.2), click Edit (by the Coordinate System box), the Map Coordinate Information dialog box will open (Figure 5.4).



Figure 5.4 Map Coordinate Information Dialog Box

      1. For HEC-RTS 3.1.1, the watershed must have a map coordinate system defined, this includes all of the map layers and the models. To get the correct projected coordinate system, click Load from File (Figure 5.4), an Open browser will open (Figure 5.5). Browse to the location where a map layer with the correct projected coordinate system, select the map layer, click Open. The Open browser will close (Figure 5.5) and now the Map Coordinate Information dialog box will contain information about the projected coordinate system (Figure 5.6). Click OK, the Map Coordinate Information dialog box will close (Figure 5.6). Now on the Create New Watershed dialog box, the Coordinate System box (Figure 5.2) contains the name of the projected coordinate system (i.e., USA_Continguous_Albers_Equal_Area_Conic_USGS_version) for the watershed.


Figure 5.5 Open Browser

Figure 5.6 Setting Projection Based on Existing Projection

      1. From the settings box, the user can select the time zone based on United States Time Zone (default) or International Time Zones (Figure 5.2). From the list, select the appropriate time zone for the watershed. Note that HEC-RTS runs models in "watershed time", which is the time zone without any "daylight saving" component. (The models are generally unable to handle the daylight savings time shift. HEC-RTS can handle the shift if the view time zone is set correctly.).


      1. Click OK, the Create New Watershed dialog box will close (Figure 5.2), and the Watershed Summary dialog box will open (Figure 5.7). The Watershed Summary provides a summary about the created watershed and lets the user know that certain items cannot be changed when a watershed is created.


Figure 5.7 Watershed Summary Dialog Box

      1. Click OK, the Watershed Summary dialog box will close (Figure 5.7), and the HEC- RTS main window (Figure 1.1) will now contain the new watershed. Also, a Next Steps dialog box will open (Figure 5.8) that provides the user with a list of what to do next in creating an HEC-RTS watershed.


Figure 5.8 Next Steps Dialog Box