The data used on this website comes from four underlying sources, which are not entirely consistent. For presentation purposes, river level information is merged into a single database, but not every data field in that database is populated for every monitoring station. Things like catchment areas and river names, in particular, are often missing. Where possible, we are fixing these manually, but it's an ongoing and time-consuming process.
Flood warnings and forecasts are currently only available for England and Wales. The Scottish Environmental Protection Agency (SEPA) does publish flood warnings, but these are not made available in a form suitable for re-use on other websites. The five day flood forecasts are a joint project between the Met Office and the Environment Agency in England and Wales, and SEPA has no equivalent.
River level monitoring stations are mechanical devices operating in a hostile environment. They can, and do, go wrong! Sometimes, data is missing from the most recent updates, and, occasionally, the data supplied is incorrect. As far as possible, we try to exclude data that is clearly wrong (eg, a water level that's so high it would indicate a flood of Biblical proportions) from the displayed graphs and calculated statistics. However, there's no easy way to account for other possible problems, such as a stuck gauge that is not correctly recording the rise and fall of a water level.
Any monitoring stations that we have not had data from for over a week are removed from this website until we get fresh data from them. Stations with more recent, but not current, data are available on the site but their data will be marked as "stale" on the relevant page.
The reporting frequency of river levels varies. In some cases, levels may only be updated once a day. During flood events, the reporting frequency is increased for affected locations, in some cases up to four times an hour. This is entirely subject to the underlying data source, and is beyond our control.