What kind of plants are you going to be planting.?
What is the water pump supplying to ? a water fall ? a stream? ..
Ok, firstly, if you want the water pump there, you are going to have to use the eggcrate method of building up your land, so that you can have a false bottom to have the water flowing. This means a couple things
1. Either your built up land is going to have to be pretty high, if you want to have plants that can't have extremely moist soil. or, you have to use plants that like really wet, like bog plants, or you have a very shallow land area.
2. If you want to have a dry soil base, you need to get some acryllic or whatever they use nowadays, and seal that land area off. I suggest with an area for the water to get to the pump behind.
If your tank is big enough, i suggest the eggcrate method. Looks to be a effective way of seperating the land and water, so basically building a false bottom.
Heres a link to that method
If you actually want to cordon the land area off, check out this guys other tank