This idea was a idea I found a while back
First dig about 3 to 4 feet down to make the general shape of the greenhouse,next use the soil u dugout to make walls/hills on the outside edges,next add the green house film over the area,u can make it so it also collects water for your pond(make sure the water doesn't go directly to the pond as snowmelt can be cold).
A few notes:make sure u don't forget to add a entrance/ exit,u may need supports for your green house tarp depending on size and shape,u will also notice I didn't tell u how to make a pond or what tropical plants to add because those decisions r up to u.
First dig about 3 to 4 feet down to make the general shape of the greenhouse,next use the soil u dugout to make walls/hills on the outside edges,next add the green house film over the area,u can make it so it also collects water for your pond(make sure the water doesn't go directly to the pond as snowmelt can be cold).
A few notes:make sure u don't forget to add a entrance/ exit,u may need supports for your green house tarp depending on size and shape,u will also notice I didn't tell u how to make a pond or what tropical plants to add because those decisions r up to u.