> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/~/changes/GiVD5ID0WVyRIAumaMy2/introduction/routing-units.md).

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