Creating larger lakes without foil is a little more work. A standard method is to use stomped clay. Dig the hole for the lake, fill it with a layer of clay, water it a little and trample on it until it forms a hard shell. You may need to apply many layers before you can fill the lake. This method is not too expensive, but the created lakes may be only partially filled with water and dry out easily in hot seasons.

The third method is to use concrete to form the shell for the lake. If the inside is covered with a plastic paint, it may be almost impermeable. Unfortunately, many solvents are poisonous, so the shell may need to dry for a week or two. Another disadvantage is that these lakes can't be extended or modified after the creation.

Choose the place for the lake carefully. The lowest part of the terrain may be a good place. But make sure that no water from places with many nutritive substances flows into the lake, this may be harmful for the vegetation. Another danger are too many trees which throw too many leaves into the lake. Many water plants can prevent the water from becoming foul. If you create a lake in your garden and you have small children, make sure that they can't fall into it.