la guera - I have one word to say about your pond and that is "WOW"!
Truly amazing, well done, sure puts my hole in the ground to shame!!!!!!
I just wish I had the time and ability to do stuff like that!!
(ok, so a few more than just one word sorry lol!)
As for the original posters idea - go for it, it will look truly amazing!
And by the way, how did you do that technical drawing thing? Did you use specialist software or spend hours in MS Paint?