About this 3D model
This object was made in Tinkercad. https://www.tinkercad.com/things/fetPrXQbua4 The propellers of the mills are actually a finger spinners. You can replace it with your favorite finger spinner. There is a container at the bottom of the structure to recover the surplus water. There is very little support. (Only the barrier and the small lake) I hope this little garden will please you.