After the Rain:
Urban Runoff

Importance of Water

Reporter #1

We live in a world that depends on water. It is the lifeblood of our planet, including human existence.

For thousands of years, Earth has had the same amount of water that it has today. It is constantly cycling and recycling through Earth’s air, water bodies, and land. The water you drink today may once have quenched the thirst of a dinosaur!

All the world’s water recycles eventually, but different parts of the supply are renewed at different rates. Water in the atmosphere, rivers, and topsoil may recycle in a matter of days, while deep ocean water may take as long as 37-thousand years.

From afar, it’s hard to believe we could ever have a shortage of fresh, clean water. But a closer look reveals some startling facts.

More than 97 percent of all the water on Earth is salt water. That’s important for everything that lives in our oceans, but not as useful to those of us who live on land.

We depend on fresh water, which accounts for less than three percent of all the water on Earth. Much of our fresh water is tied up in ice caps, glaciers, and groundwater that’s too expensive to reach.

That means less than one percent of our planet’s water is available for human needs.

Reporter #1 on camera

Imagine this one-gallon jug holds all the water on Earth. The amount of fresh water available for things like agriculture, industry, commercial businesses, and household use would equal little more than a tablespoon.

Right now, there is enough fresh water for everyone on the planet. The problem is that fresh water doesn’t always exist where we need it.

Reporter #1:

As our population grows, so does the demand for this limited resource. In recent decades, increased use and pollution of our surface and groundwater supplies have actually reduced the amount of fresh water available for our needs.

The air in our atmosphere also plays a role. As air circulates around the Earth, it creates a variety of weather systems. This determines where, how much, and how often precipitation will fall to the Earth.

In some places, there may be plenty of fresh water. But in others, demand may exceed the supply.

News Anchor #1

As recently as one hundred years ago, almost everyone on Earth lived in the country. As we enter the 21st century, about half the world’s population and three-quarters of the United States’ population now lives in towns and cities.

News Anchor #2

Growing cities offer jobs, a wide range of goods and services, and variety of social and cultural activities. They also create environmental challenges that need special attention.

Continue.

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