Welcome @Guy S. ! You could wrap the pond around the tree, if that's what you're asking. Kind of mimic the kidney shape of what you currently have with the tree in the concave part. It's usually easier to build the pond first and plant the tree later, but it's a pretty little tree - I can see why you'd want to save it!
Is it in the best location do you think? It isn't impossible to move a tree if you're careful about how you dig it up. Just a thought!
Two things that I would worry about are 1) The roots of the tree eventually growing into your liner and either causing a leak or constricting the growth of the tree. 2) Japanese Maples do not tolerate wet soil, so if the pond overflow is not directed well away it will kill the tree.
Being that the tree is small, it might easily be relocated and offer up that area to make your pond larger, and the tree could be used as an accent nearby on higher ground. JMO
I live in Southwest Missouri...planted a Japanese maple by my pond and we've had a lot of rain this year ....as long as the soil drains good you'll be good...the leaves are the only thing that get me I spend a lot of time in the spring and fall cleaning leaves....I read that Japanese maple roots go two feet down and then start to Branch out so I put my tree on the shallow end of my pond...it's about 4' tall....been there for a couple years and no problems so far