The Input file is a standard EPANET input data file that describes the system being analyzed. It can either be created external to the application being developed with the Toolkit or by the application itself. It is the first file name supplied to the EN_open function. A project's data associated with its Input file remains accessible until the project is closed down with the EN_close or deleted with EN_deleteproject.

The file is organized by sections where each section begins with a keyword enclosed in brackets. The various keywords are listed below. Click on a section to see the format of the data it contains.

Network Components	System Operation	Water Quality	Options & Reporting	GUI Support
[Title]	[Curves]	[Quality]	[Options]	[Backdrop]
[Junctions]	[Patterns]	[Reactions]	[Times]	[Coordinates]
[Reservoirs]	[Energy]	[Sources]	[Report]	[Vertices]
[Tanks]	[Status]	[Mixing]		[Labels]
[Pipes]	[Controls]
[Pumps]	[Rules]
[Valves]	[Demands]
[Emitters]

The order of sections is not important. However, whenever a node or link is referred to in a section it must have already been defined in the [JUNCTIONS], [RESERVOIRS], [TANKS], [PIPES], [PUMPS], or [VALVES] sections. Thus it is recommended that these sections be placed first.

Each section can contain one or more lines of data. Blank lines can appear anywhere in the file and the semicolon (;) can be used to indicate that what follows on the line is a comment, not data. A maximum of 1024 characters can appear on a line.

The ID labels used to identify nodes, links, curves and patterns can be any combination of up to 31 characters and numbers.

The GUI Support sections are provided to assist an external program that wishes to draw a visual representation of a project's network.