The Setup module is used to configure the inputs, models, and outputs that define the behavior of a watershed. It also enables you to build a visual representation of the watershed for display in the map window. Within this module, you'll define the watershed’s physical layout, including map layers and time series icons. This section provides an overview of the Setup interface.

To access the Setup module, click the Setup tab in the Watershed Pane, or select the Setup button from the Modules Toolbar.

Layout

The key components of the Setup module are illustrated in the figure below.

Watershed Name

The name of the watershed is displayed at the top of the Setup tab.

Watershed Tree

The watershed tree lists all elements of the watershed model, including the model alternatives, stream alignments, and forecast runs.

Content Pane

The content pane shows detailed information about the item selected in the watershed tree. For example, when a forecast run is selected, the content pane displays details such as the forecast run key and the associated model alternatives.

Menu Bar Overview

When the Setup module is active, the menu bar provides access to tools that support the setup and configuration of the watershed. While the File, View, Maps, Scripts, Tools, Windows, and Help menus are covered in the Main Window Overview, the Watershed and Models menus contain specific options related to watershed setup.

Watershed Menu

  • Watershed Properties - View and edit general properties of the watershed.
  • Files - Access a list of files associated with the watershed.
  • Stream Reach Alias Editor - Edit aliases for stream reaches.
  • List of Streams - View stream names along with their descriptions.
  • Team
    • Sync with Master Watershed - Upload local watershed files to the master watershed location.
    • Download Master Watershed - Download files from the master watershed repository to your local environment.
  • Stream Alignment
    • Import - Import stream alignment data from a shapefile.
    • Export - Export current stream alignment to a shapefile.

Models Menu

  • Next Steps - View a checklist of recommended steps for initial watershed setup.
  • Program Order - Define the execution sequence for plugin models.
  • Import - Import model alternatives into the watershed project.
  • Model Alternative Keys - Assign unique keys to identify model alternatives.
  • Forecast Runs - Create and manage forecast run configurations.
  • Model Linking - Define how different models are connected or share data. 
  • Edit Extract - Create and manage groups for input data extraction.
  • Edit Post - Create and manage groups for posting forecast results.
  • HMS - Access tools for resolving HEC-HMS schematic drawing issues (More information can be found Correcting the HEC-HMS Schematic Display in the CAVI).
    • Forecast Alternative Manager -  Add, edit, or delete HEC-HMS forecast alternatives.
    • Junction Location Mapper - Display the location of each HEC-HMS junction in relation to the stream alignment.
    • Reach to Stream Mapper - Show how each HEC-HMS reach maps to the stream network.
    • Coordinate Information -  View the coordinate system used by the HEC-HMS model.

Stream Alignment Toolbar

When the stream alignment is displayed in the Setup module Map Window, two additional tools become available: the Stream Alignment Tool and the Stream Node Tool.

 Stream Alignment Tool - Use this tool to create, edit, or delete elements that make up the stream alignment. The Stream Alignment represents the stream network within the watershed.

 Stream Node Tool - This tool lets you create and edit stream nodes and junctions within the stream alignment. Stream nodes define the start and end points of stream elements and represent locations where streams connect (junctions).

Creating a New Watershed

If you don't have an HEC-RTS watershed, the first step is to create a new one. After configuring the new watershed, HEC-RTS will generate a directory structure in the specified location. The new watershed will become active in the main window, and the tools for configuring watershed components will be available. At this point, you can continue configuring the watershed by adding layers, setting map window preferences, creating time series icons, establishing database connections, and setting up models and model alternatives.

For detailed instructions on creating a new watershed, refer to the Creating a New Watershed tutorial.

Coordinate Systems

A coordinate system is a method that uses numerical values (coordinates) to determine the position of a point or geometric feature within a geographic framework. There are two main types of coordinate systems:

  • Geographic coordinate systems, which use latitude and longitude to define locations.
  • Projected coordinate systems, which represent a geographic coordinate system on a flat plane and use linear units (such as feet or meters) for coordinates. Available options are:
    • X-Y
    • Google/Bing Web Mercator
    • Universal Transverse Mercator
    • State Plane Coordinates
    • Albers Equal-Area Conic
    • Lambert Conformal Conic
    • Transverse Mercator
    • Albers Equal-Area Conic (SHG)
    • Polar Stereographic (HRAP)

HEC-RTS supports "on-the-fly" coordinate system transformation, allowing map layers created in different coordinate systems to display together in a unified view. For example, background maps from Internet sources like Google® Maps or OpenStreetMap can be displayed within your watershed, as long as:

  • The watershed has a defined georeferenced coordinate system.
  • Each map layer includes a coordinate system definition (e.g., a .prj file or equivalent).

The positions of key watershed elements—such as time series icons, stream alignments, and study layers—are stored using the watershed’s coordinate system. This system is set when you create a new watershed and establishes a grid based on the World Coordinate System (WCS). While HEC-RTS can transform different coordinate systems automatically, you may need to use GIS tools to identify or convert layers before using them. Using a consistent coordinate system across all layers is recommended for more accurate alignment and better performance, especially when working with large maps.

Time Zones

When creating a new watershed, you must select the time zone that corresponds to the watershed’s location. HEC-RTS will store time series data using the selected time zone’s fixed offset from GMT, ensuring that the data is recorded in standard time only. However, for viewing purposes, you can choose to display data in local time or any other time zone, with appropriate labels for standard and daylight time throughout the year.