# Routing Units

Routing Units are the spatial units in SWAT+ that allow us to lump outputs and route them to any other spatial object. Routing Units don't have a lot of properties as they mostly serve the purpose of collecting hydrographs and the simulation of the processes generating those is controlled by the properties of the individual elements within a routing unit. 

* [**rout\_unit.rtu**](https://swatplus.gitbook.io/io-docs/~/changes/GiVD5ID0WVyRIAumaMy2/introduction/routing-units/untitled) references other files specifying the elements that are part of a Routing Unit and its topographic and field properties.
* [**rout\_unit.def**](https://swatplus.gitbook.io/io-docs/~/changes/GiVD5ID0WVyRIAumaMy2/introduction/routing-units/untitled-1) specifies which elements a Routing Unit contains.
* [**rout\_unit.ele**](https://swatplus.gitbook.io/io-docs/~/changes/GiVD5ID0WVyRIAumaMy2/introduction/routing-units/untitled-2) lists all elements that are part of a Routing Unit.