I wonder ... Why, when & if.

1. Why they did it like this? It conveys the impression they wanted the little stream through, out and away, as fast as practicable and might have been happy to pipe in underground.
2. When they decided to do this?
3. If they'd do the same today? Or make more of a feature of it.

As I'm back-blipping I can say "I wish we'd gone today." Weather's VASTLY better, we can see more than 100yds.