No, just went with one of the detailed satellite backgrounds from the iD editor.

Have you seen this site?
https://osm.mathmos.net/postboxes/progress/N/

I did all of N6 (good exercise) and have been working through the neighbouring areas.

Ah, apologies for this. I noticed in the iD editor that it simply appears as "Building", so "Train Station" seemed a closer match.

Updated in changeset/86918680

Agreed - the first tag choice renders it as open water, which is wrong.

Why the review request? I'm unsure about the tags in use, and don't want the covered reservoir to render as a square lake.