SWATGenX I/O reference

Applies to SWATGenX engine extensions · Updated August 2026

File-level reference for what a SWATGenX package contains and how the SWATGenX engine extensions read and write it. Stock SWAT+ input files are documented upstream; this reference covers only SWATGenX deltas and extensions.

A SWATGenX model bundle is a standard SWAT+ project plus a defined set of additions: sidecar metadata, optional PFAS fate-and-transport inputs, engine output-filtering and NetCDF controls, an optional sibling MODFLOW 6 package, research-grade daily coupling files, and calibration artifacts. Each chapter documents one subsystem: purpose, field-by-field schemas with types and units, and the reader/writer code that defines each file. The compile chapter covers cloning and building the SWAT+ fork that reads those extensions.

Link-out policy for stock SWAT+ files

Stock SWAT+ input/output files (file.cio, hru.hru, channel.cha, soils.sol, time.sim, plant.ini, …) are read and written by the upstream SWAT+ code and documented in the official SWAT+ I/O documentation. This reference does not duplicate that material. Where SWATGenX modifies a stock file (print.prt patches, recall handling, Editor/QSWAT+ version pinning), only the delta is documented here — see the SWAT+ input files chapter. Official stock-build docs for upstream SWAT+ stay upstream; the fork compile procedure is documented here.

SWAT+ I/O documentation (official)

Every schema in this reference is transcribed from the engine readers/writers (Fortran) or the generator scripts (Python) that produce the files. When engine code and this reference disagree, the code is authoritative — report the discrepancy.