Reservoirs refers to paces where water are stored. The largest water reservoir on earth are the oceans which contain about 97% of all the water on the earth.
The next highest reservoir are the glaciers or the polar ice caps. These hold quite an enormous amount of the water found on earth.
Surface and other fresh water only account for about 1.2% of all the surface water on earth.Ground water accounts for a very minute percentage of the water found on earth.
