This map renders with WebGL and needs JavaScript. The underlying data is plain JSON and stays usable without it — see data/v1/ in the repository, or the Environment Agency Hydrology API directly.
data/v1/
Loading gauging stations…
Environment Agency open data
Colour is each station's discharge against its own record, not an absolute scale — 20 m³/s is a drought on the Thames and a flood on a chalk stream.