There are millions of lakes on Earth, and almost half of them are in Canada
One very large lake, Lake Baikal in Siberia, contains 20 percent of all the freshwater on the surface of our planet
Another way lake provide a lot of water is that lake water is easy to get – land surrounds a lake on all sides and makes the water fairly calm and quiet
Last, the freshwater supply in lake can come from different sources, instead of just one source
Most lakes are areas that glaciers covered in past
Some lakes form when rocks stop a river from flowing
Lakes also form when rainwater fill the opening of an extinct volcana