Primary Layers are automatically created as part of key actions within a watershed:

  • Time Series Icons layer – created when a watershed is created

  • Stream Alignment layer – created when a stream alignment is defined

  • Gridded Data layer – created when a grid set is created

  • Model Schematic layer – created when forecast alternatives and forecasts are generated

These layers are foundational and are included in all watersheds, although some may be empty depending on the data available.

Time Series Icons Layer

The Time Series Icons layer is automatically created when an HEC-RTS watershed is created. Initially, this layer is empty. As you define time series icons for your watershed, they are added to this layer. These icons first appear in the Acquisition, Visualization, and Setup modules. Once forecast alternatives and forecasts are created, then the layer also becomes available in the Modeling module.

Time Series Icon Layers help organize sets of time series icons on the map, making it easier to view and manage data. You can create multiple layers to separate icons by data type, location, or function. For example, a gage might report stage and precipitation, and also compute flow from stage. In this case, you could create separate layers named Stage, Flow, and Precip to keep the data organized. Creating layers in this way helps you focus on the specific type of data you want to analyze.

Stream Alignment Layer

The Stream Alignment layer becomes available in the Setup module after a stream alignment has been defined for a watershed. It is also accessible in the Modeling module when a forecast is open. This layer contains three sub-layers: Stream Junctions, Streams, and Stream Nodes. 

Gridded Data Layer

Gridded data layers are available in the Visualization and Modeling modules when grid sets (e.g., precipitation, temperature, snow) have been created or computed for the watershed. These grid sets are generated using HEC-MetVue.

Model Schematic Layer

After you have created forecast alternatives, generated a forecast, and set it as active, the Model Schematic Layer will appear in the Map Layers editor. This layer visually represents the computational models used in the active forecast alternative.

Shortcut Menu

You can access the shortcut menu by right-clicking on any primary layer in the Map Layers editor. This menu offers various commands to manage and customize the display and behavior of the primary layers.

Available Commands

  • Move to Top - Moves the selected layer to the top of the layer tree.
  • Move Up - Moves the selected layer up one position.
  • Move Down - Moves the selected layer down one position.
  • Move to Bottom - Moves the selected layer to the bottom of the layer tree.
  • Properties - Opens the properties dialog for the selected layer. Depending on the layer, the properties may be editable or read-only.
  • Import (Stream Alignment layer only) - Opens the Import Stream Alignment dialog, allowing you to import a stream alignment from a shapefile (.shp).
  • Export (Stream Alignment layer only) - Opens a Save browser, allowing you to export the stream alignment to a shapefile (.shp).
  • Add Icon Layer (Time Series Icons layer only) - Opens the New Time Series Icon Layer dialog, allowing you to create a time series icon layer.
  • Show/Hide Legend (Gridded Data layer only) - Toggles the legend on or off in the map window for a gridded dataset.