OS Open Rivers is available in the following formats:
Geography Markup Language (GML): A national vector dataset in GML 3.2.1 Simple Features Profile – level 0.
Shapefile: A national vector dataset in Esri shapefile (.shp) format.
GeoPackage: A national vector GeoPackage file (.gpkg).
Vector tiles: A national vector tiles file in MBTiles format.
All formats are zipped using gzip.
OS Open Rivers is supplied as an online download and is available without registration from the OS Data Hub Open Rivers page. You can select a data format during the download process.