I understand what you want. My suggestion would be to visit a local pet shop that specializes in fish or amphibious aquariums. That might give you ideas. However, my suggestion would be to go with simulated water. The canal or stream bed can be done with plaster of Paris or similar material, painted to the desired color with acrylic paint. While there are several water simulator materials, including two-part stuff, I found that applications of Modge-Podge makes great-looking water. It has very little odor and gives a nice glossy finish when it dries. You can imbed fishermen and rowboats and even twigs that look like trees.
Stay well and safe!