Not sure if this is the same map you're talking about, but Ordinance Survey made a map[0] using data they had in 2013, and then again in 2014. This was based on

Not sure if this is the same map you're talking about, but Ordinance Survey made a map[0] using data they had in 2013, and then again in 2014. This was based on height data at 50m resolution. It's hard to see how OS capture height exactly, I imagine via aircraft[1]. Not sure whether they are the source of the existing data the Environment agency has; I doubt it as their data has a max resolution of 5m while the government's is 1m. [0] https://www.ordnancesurvey.co.uk/innovate/developers/minecraft-map-britain.html https://www.ordnancesurvey.co.uk/innovate/developers/minecra... [1] https://www.ordnancesurvey.co.uk/international/knowledge/data-collection-management.html https://www.ordnancesurvey.co.uk/international/knowledge/dat...