Flooding can threaten communities and put huge strains on local services. Now a web app uses open data to monitor river levels across England and Wales, from huge estuaries to small streams.

GaugeMap, developed by software firm Shoothill, uses data from England’s Environment Agency as well as Natural Resources Wales to show levels at 2,400 locations.

“Interest in GaugeMap’s been universal. It has a multitude of users, from the emergency services to boaters, fishermen, kayakers and canoeists,” says Shoothill’s managing director, Rod Plummer.

“Different users have different needs – kayakers and canoeists need different water conditions, and so do fishermen. Farmers use it for water abstraction.

“We have one guy who runs a cruising boat – he uses it so he can get his boat under the bridge.”

Each of the 2,400 locations has its own Twitter feed as well – so if there’s a river close by, you can check its levels wherever you are.

“We thought there’d be plenty where nobody would bother, in the middle of nowhere. But the followers have been spread out across the place,” he says.

“We tweet twice a day, but if there’s a flood situation, we can tweet more often.”

Keen to work with councils

It builds on another map Shoothill designed with Environment Agency data in 2011 – FloodAlerts, which is used by the BBC, Sky News, and the Environment Agency itself.

“Originally, it was on Facebook only – it placed alerts on your feed so others could see it,” Plummer explains.

With GaugeMap, Plummer says he wanted to improve on what the agency was already providing with its River Levels on the Internet service.

While the Environment Agency’s data is now available for all to use, the river data is also available through Shoothill, which is keen to work with local authorities on gathering their own river data to further improve GaugeMap.

“We don’t pretend to be environmental experts. Our mantra is data visualisation. We like to make the complicated simpler and the boring interesting,” Plummer says.

“Floodmap can get on the front of the BBC website and get hammered by a million hits a day – there’s a lot of oomph behind it. So we’re more than happy to provide and embed maps for local authorities in their own patch.”

Welsh Bridge, Shrewsbury, by brianac37, used under CC BY 2.0.