The Time Series Icons layer is created for the Acquisition, Visualization, and Setup modules when an HEC-RTS watershed is created. At first, this layer is blank, but as you create time series icons, the Time Series Icons layer includes all of the time series icons that you have defined for your watershed. Time series icons are available in the modules Acquisition, Visualization, and Setup modules, once forecast alternatives and forecasts have been created then the Time Series Icons layer will display in the Modeling module.