Grow Career Publication
Chapter 16: Water: A Precious Resource
Water is a limited resource. It is needed for all living things and must be managed well to ensure we have enough for our needs and to protect our environment. Water is a precious resource. We can’t live without it.
How much water is available
There’s a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (that’s 326 million trillion gallons) of the stuff (roughly 1,260,000,000,000,000,000,000 l) can be found on our planet. This water is in a constant cycle — it evaporates from the ocean, travels through the air, rains down on the land and then flows back to the ocean.
The oceans are huge. About 70 percent of the planet is covered in ocean, and the average depth of the ocean is about 12,100 feet (3,688 meters). Ninety-eight percent of the water on the planet is in the oceans, and therefore is unusable for drinking because of the salt. Less than 3 percent of the planet’s water is fresh, but about 1.6 percent of the planet’s water is locked up in the polar ice caps and glaciers. Another 0.36 percent is found underground in aquifers and wells. Only about 0.036 percent of the planet’s total water supply is found in lakes and rivers.
