The water you drank this morning might have been the same water
that once rained down on a Tyrannosaurus, froze on a woolly
mammoth, flowed down the Nile to bring new silt to an Egyptian
farm – or filled the bathing pool of Julius Caesar. The water we
use now is the same supply that has been on Earth for billions of
years. Its quality is renewed again and again by the natural
water (hydrologic) cycle.
In the water world, water is commonly measured in acre-feet. But
what is an acre-foot? One acre-foot equals about 326,000 gallons,
or enough water to cover an acre of land, about the size of a
football field, one foot deep. An average California household
uses between one-half and one acre-foot of water per year for
indoor and outdoor use.
The nation’s surface-water resources—the water in the nation’s
rivers, streams, creeks, lakes, and reservoirs—are vitally
important to our everyday life. The main uses of surface water
include drinking-water and other public uses, irrigation uses,
and for use by the thermoelectric-power industry to cool
Your water footprint is the amount of water that you use in a
day. Every person has a unique water footprint based on the ways
water is used. One easy way to begin the process of calculating
your water footprint is to look at your family’s water bill for a
month. Divide the amount used by the number of days in the month
and then divide again by the number of people in your family. You
might be surprised at how much water you use in a day at home.
The actual amount used per capita varies greatly from person to
person, region to region and season to season.
People use water for direct and indirect purposes. Direct
purposes include bathing, drinking and cooking. In most developed
countries, urban water users are connected to water through their
municipal water delivery system and their home plumbing system.
People turn on the tap, water comes out and they use it. Indirect
water (also called “virtual water”) use refers to the water used
to produce the g
Earth has a finite amount of fresh, usable water. Fortunately, water is naturally recycled (collected, cleansed, and distributed) through the hydrologic cycle. Humans have developed the technology to speed this process. However, because of diverse factors (drought, flood, population growth, contamination, etc.) water supplies may not adequately meet a community’s needs. Conservation of water can ensure that supplies of fresh water will be available for everyone, today and tomorrow.
Clean fresh water is vital to our lives and many of the plants
and animals we depend on. Most people think water pollution comes
directly from a factory or other known source, a type of
pollution known as “point source pollution.” Because of laws
passed in the 1970s, most of those sources of pollution have
cleaned up their act. Today, the biggest source of pollution is
us – you and me. This type of pollution is known as “nonpoint
source pollution” because it can’t be traced to one single
source; we can’t tell how much pollution is coming from where.