Hello and welcome to FF! To build a vivarium like that, will need to create a false bottom. Main purpose is to raise the soil for plants above the water section so it won't soak up the water and become a bog.

There are a couple nice articles in the forum's how-to article section and a few builds in the vivarium section. This one is a good read: http://www.frogforum.net/vivarium-te...aludarium.html. Good luck !