You might be surprised at the amount of research that goes into something as short as this. The Broads Authority were rightly keen to ensure that the history and geology given here was acurate. And, fortunately, they had people who knew (even if they didn’t always agree on the details).
This was another job I did with Michael Lawson at Spike (now BluebottleCGI). He got the gig and brought me in to do the 2D bits. I like working this way – seasoned professionals coming together as informal teams. It can provide a high quality and cost effective service for the client. Perhaps “no one ever got fired for choosing IBM”, but I bet they paid over the odds.