From the about page:
The Shoothill GaugeMap is the first interactive map with live river level data from over 2,400 Environment Agency and Natural Resources Wales river level gauges in England and Wales.
The extensive network of river level gauges across England and Wales covers all the major rivers as well as many smaller rivers, streams and brooks. The data displayed on each of the river level gauges on GaugeMap is recorded at 15 minute intervals by the Environment Agency and Natural Resources Wales.
For more information on how to use GaugeMap, please see the help file.
If you live in England or Wales and are concerned about potential flooding, this may be the map for you!
The map reports data from 2400 river level gauges and you can follow individual gauges via Twitter.
I first saw this in a tweet by Rod Plummer.
In case you are interested in other river gauge information:
RiverGauges.com USA only but excludes most of Texas, Georgia, Florida, and most of the Eastern seaboard. Not sure why. Has historical and current data.
RiverApp USA and Europe, over 1,000 rivers. Can’t really comment since I don’t have a smart phone. (Contact me for an smail address if you want to donate a recent smart phone.)