Visual OTTHYMO v2.3 is a single event hydrologic model which means it can simulate runoff from single storm events. The hydrographs generated are based on unit hydrograph theory and can be used for uncalibrated or calibrated modelling studies. VO2 can give users reliable results without a large number of input parameters, giving the model an edge over other "parameter intensive" models. VO2 is well suited for the following levels of hydrologic study:

• Watershed Study
• Sub-watershed Study
• Master Drainage Plan
• Functional Stormwater Management Design
• Site Plan Stormwater Management Design
• Stormwater Management Pond Design.



The Visual OTTHYMO v2.3 interface is a Graphical User Interface (GUI). The interface was designed with the philosophy "The Model Schematic is the Model". This means that when a user builds the model schematic they are also building the actual model (previously known as 
an input file), including content and connectivity. The interface therefore provides the following functions:

• Schematized representation of the model
• Input parameter entry and storage
• Project and scenario management
• Hydrologic analyses
• Output Control (tabular, graphical, text file)
• Tabular view of all objects