The TR-55 Interface provides a complete graphical interface to the U.S. Soil Conservation Service TR-55 hydrologic analysis model. All modeling parameters and input data are entered through interactive graphics and easy-to-use dialog boxes, enabling the user to easily define the TR-55 hydrologic routing model.

TR-55 is perhaps the most widely used approach to hydrology in the United States. TR-55 provides a number of techniques that are useful for modeling small watersheds. TR-55 utilizes the SCS runoff equation to predict the peak rate of runoff as well as the total volume. TR-55 also provides a simplified "tabular method" for the generation of complete runoff hydrographs. The tabular method is a simplified technique based on calculations performed with TR-20.