Yet another way which is very simple, 1 create a stone, 2 drop onto your ground plane 3 resize and sink halfway into ground plane, 4 make negative, 5 make ground plane positive, 6 group 7 Create a water plane and drop just below ground plane I know you you shouldn't use an infinite plane for creating a lake etc. but it is an option

Oh, let the sun beat down upon my face. I am a traveler of both time and space ....Kashmir, Led Zeppelin