I hate to disappoint you, but your questions fall outside the realm of our mission:
To clarify misconceptions about the Catholic Church and Catholic teachings.
What I can do is give you my opinion as a lay Catholic.
You are more than welcome to construct whatever pond or well you want on your property and dedicate it to a saint.
That said, if it is open to the public, you would want to get the approval of your local bishop on your plans. Bishops of the Church are there to ensure anything in their diocese that is "Catholic" is, indeed, "unmistakably Catholic".
Although a priest blesses your pond or well, it does not follow that pouring unblessed water into the pond or well, makes it holy water. You would have to have a priest bless the unblessed water you plan to put into the well on a regular basis which shouldn't be too much of a problem.
I hope this helps,