The GUI is a Windows based program used as a convenient way of entering data for a watershed model and viewing simulated results. The GUI program has the following (minimal) computer system requirements:
- IBM compatible PC
- at least 64 MB RAM (complex simulations may require significantly more RAM)
- Windows XP or more recent operating system.
The GUI Main Window is divided into several components as shown below:
The Caption contains the name of the application and the file name of the open project file (C:WARMF/Catawba.WSM). The 
on the right side of the Caption is used to make the GUI an icon or reduce its size. The 
in the right corner closes the program.
The Menu has many functions which may be accessed either with the mouse or the keyboard. To access the menu with the mouse, click on the item with the left mouse button. To access the menu using the keyboard, press the Alt key and let go. Then type underlined letters or use the arrow keys to move through the menu. The 
button on the left side of the Menu is used to manipulate the Map Window within the GUI main window. The 
button on the right side of the Menu is used to reduce the size of the Map Window within the GUI main window. The on the right end of the menu closes the Map Window without closing the program.
The Tool Bar has short cuts to some of the most frequently used menu functions. It also contains several tools which change the actions taken when using the mouse. When the mouse is held over one of the icons, a brief description of the function appears in the Status Bar.
The Draw Tools are used to create shapes, lines, and text in the Map Window. Choose a draw tool by clicking on it with the mouse. Then use the mouse on the Map Window to add to the Map. To restore the mouse to its original functions, click on 
in the upper left corner of the Draw Tools. When the mouse is held over one of the icons, a brief description of the function appears in the Status Bar.
The Map Window is the area on which the Map is drawn.
The Map is the representation of the watershed being modeled. It consists of objects, which can be modeled entities, descriptive text, and other shapes.
The Status Bar has two functions. The normal display, shown above, shows the color of fills and lines, the font and size of text, and keyboard settings. For example, the status bar shown above indicates that shapes created would be white with a black border; entered text would be Arial 12 point font, and the keyboard is set with the CAPS lock, NUM lock, and SCRL lock all on. When the mouse is moved over the icon representing a function, the status bar is temporarily replaced with text describing the function. For example, when the mouse is over the 
icon, the following message appears in the Status Bar.