Where Does the Water Go?

About 200 million acre-feet of water falls on California each year as snow or rain. That’s enough water to cover 200 million football fields a foot deep in water. That’s a lot of water!

But most of that water-about 65%-is used by plants or evaporates from the ground or from lakes and rivers. The rest-about 35%-becomes “runoff.” Some of the runoff flows into the ocean. The remaining water is available for us to use. Of all the water that falls in California, we currently use only about 25%-in our homes and businesses, on our farms, and for our environment. Here is where the water goes:

Urban Water Use

About 11 % of California’s available water is used in urban areas-cities and towns where people live and work.

• Over half of urban water is used in homes- inside and out. Not every home uses water the same way, however. For example, a person who lives in a house with a large yard will use a lot of water outside to water the lawn and garden. A family of 5 living in an apartment may not use any water outside, but will use more water inside for bathing, cooking, and flushing toilets.
• Urban water is also needed in businesses (such as shops, office buildings, hotels, restaurants, car washes, and golf courses), industry (to make paper and plastics and other products, to cool hot metal in steel mills, as an ingredient in drinks and foods, and to clean and air-condition factories), and for public services (like street cleaning, fire fighting, and watering plants and grass along streets and in parks).
• And about 10% of urban water is lost to leaks in pipes, faucets, hoses, toiletsanywhere water is used.
• Water is needed for urban uses throughout the State, but southern California has the highest urban water use.

Agricultural Water Use
California farmers grow more than 250 kinds of crops, including lettuce, tomatoes, grapes, strawberries, melons, rice, hay, and cotton. Many crops-such as almonds, artichokes, kiwifruit, nectarines, olives, raisins, and walnuts-are not grown in any other states. California grows about half of the fruits and vegetables eaten in America.

Growing all this food takes quite a lot of water. About 43% of California’s available water is used in agriculture. Besides growing food for people, water is also used to grow crops, such as alfalfa and corn, that feed livestock, which is also used for food-meat, eggs, and milk products. Water is also needed for the animals to drink. A dairy cow can drink 35 gallons of water a day!

Water is important not only for the crops and livestock, but also for the soil. As irrigation water flows through the ground, it cleans out mineral salts, which can be harmful to crops growing in the soil.

Environmental Water Use
It’s not just people that need water in California. The natural environment also needs water for:

• streams and rivers to flow
• wetlands to survive
• plants and trees to grow
• animals to drink
• fish and other aquatic animals to live in.
• About 46%, a little less than half, of the water in California that is available for us to use remains in the natural environment. This water keeps many plants and animals alive.

Near the coast, fresh water is also sometimes needed to keep salt water out of fresh water basins. If the fresh water-a lake or river becomes “contaminated” with salt water, the ecosystem could be damaged. And fresh water from that source may no longer be available. In other areas, water also seeps into the ground, keeping enough water in our groundwater basins.

In California, most of the rain falls in the north, creating many rivers, streams, and lakes. Therefore, the environmental needs for water are highest in northern California.

Continue to learn more about water conservation.