The initial impetus for setting up a river levels website came in the aftermath of flooding in my local area. While the Environment Agency's own website does provide river level information, it has to be said that the presentation of the data is somewhat limited. So I decided to set up my own version.
In particular, what I thought I could do better was to present the data in a more accessible visual format, and with better cross-referencing between different sites (so, for example, when viewing the data for the River Avon at Evesham, there are also quick links to other locations on the Avon and other rivers near Evesham). Putting the locations onto a Google map also makes it easier to find those which are relevant as you don't need to know precise names.
As originally set up, this was all entirely unofficial. The Environment Agency didn't make the necessary data available under a suitable licence, so to get it I needed to screenscrape the EA website. This was less than ideal for a number of reasons, including the fact that it's rather tedious as well as the risk that the EA would try to get the site shut down.
However, things have taken a turn for the better. Following a concerted campaign from Open Data campaigners, the EA is in the process of releasing more of its data under the Open Government Licence, and that now includes river level and flood warning data.
It still isn't perfect. Rather than publish the data in a suitable format itself, the EA has contracted it out to a commercial partner, Shoothill Ltd. There's a potential conflict of interest there, since Shoothill was previously one of the few commercial suppliers of flood and river level data, and still sells value-added products based on it. There are also technical barriers to using the API provided by Shoothill, which requires registration and then authentication in order to obtain the data. Although obtaining the data is within the ability of a competent programmer, it isn't acessible to someone without those skills. While within the letter of the OGL, as registration is free, this is does seem somewhat contrary to the spirit of Open Data.
Another problem with the Shoothill data is that it doesn't quite match the data published on the EA's own website. There are also some inconsistencies, such as some tidal and downstream locations not being correctly identified.
Entirely independently of the changes to the way that the EA supplies data, I had also decided that the RiverLevels.info website was due an update to bring it into line with modern web standards. In particular, I wanted to make it work properly on mobile and tablet devices as well as desktop and laptop PCs.
What I've decided to do, therefore, is take advantage of the new open data to create a new website running in parallel with the old one, rather than simply updating the old one. The new one, at RiverLevels.uk, uses data from Shoothill's API, while the old one continues to get data by screenscraping the EA website.
The new website also contains flood forecasts and alerts, which are now also open data and available via the API. In the long run, I aim to add more detailed flood data including risk maps.
In the long term, my plan is still to shut down the old website completely and replace it with the new one. But the twin website operation in the short term allows me to develop the new one without forcing change on users of the current site until I'm sure that everything is working as it should be on the new one!