Once you have decided the type of pond you want to build, your water garden site should be chosen. Most people enjoy being able to view their garden from the main living area of their home, especially in inclement weather. I personally like to place the pond a close to and large window for inside viewing and near a main door for easy access. I also suggest that he sitting location should be private enough that you can sit by the pond for hours with privacy from the neighbors. The pond should be elevated a little to prevent runoff.
Lawns can leach fertilizers, chemicals, and organic debris into the pond.
These nutrients and chemicals can contribute to algae blooms and kill your fish. The next step is deciding the type of pond liner. The main Choices are the cheaper PVC and the EDPM rubber. If you are in a sunny exposed area and want your pond liner to last more than 5 years then EDPM is a far better value for your money. Most pond liners are Firestone PondGard, a 45 mil fish grade rubber which is flexible at low temperatures and has a 20 year warranty.