WATER POWER

JR. ACE PROGRAM

HYDROLOGIC CYCLEWhere does water come from?Water is produced from a cycle on Earth called the hydrologic cycle

Water from oceans, lakes and soil evaporates into the atmosphere when the sun heats it up. The vapor is carried aloft to a height where it condenses, and forms clouds. When the clouds get too heavy with moisture, they give it up in the form of rain, which feeds the oceans, lakes and soil, to start the process all over again.

There is also a tremendous amount of water under the earth stored in caves, underground lakes and rivers, and just in between layers of rock and sediment. These waters come to the surface in the form of springs and wells, which can feed lakes and streams on the surface.

And there is water in us! People are composed of 95% water. Without it, we would die within a few days, dry up and blow away!

Water is heavy (about 8 pounds per gallon) and is affected by gravity in streams and rivers to move from high places to low places. This movement causes what we call a current. Long ago, man devised a way to make water currents work for him by building a wheel with paddles which he could run a current through and turn to make it work for him.

This wheel, which we call a water wheel, can be used to turn all sorts of machines, from those which can grind wheat and corn, to sawmills, ore hammers, and electrical generators. The water wheel can be pushed either by a current in a river at the bottom, or from the weight of water hitting the paddles at the top and using gravity to push the wheel down.

Riddle:What do water

power and gold have to do with each

other?

One famous water wheel was used in a sawmill owned by John Sutter in Coloma, California. In 1848, John Marshall was working there when he saw something glittering in the water past the wheel, where the water power had scoured out the dirt. This turned out to be GOLD ! This started the well-known California Gold Rush of 1849 which led to California becoming a state.

Answer:

Dams

Other ways water can be used for work is to store it up behind dams on rivers to make lakes. The energy stored in the water in these lakes is called potential energy. When water is raised up in the air, like behind a dam, the weight of water created by gravity is called a “head” which pressurizes the water. Since water cannot be compressed, the water at the top weighs down on the water just below it and so on, until there is a great amount of pressure at the bottom, measured in pounds per square inch, or PSI.

When this water is allowed to escape through pipes at the bottom of the lake, it does so with a great deal of pressure and movement. So, at the end of the pipe, engineers place huge structures called “turbines” with blades through which the water passes, turning them at high speeds, which turn electrical generators to make power for distribution to our homes and businesses. This is called Hydroelectric Power.Diagram of a Water Turbine

Turbine Being Erected at Hoover Dam

Turbine Room at Hoover Dam

How much energy does Hoover Dam produce on a yearly basis?

The average annual net generation for Hoover Power Plant for 1947 through 2008 was about 4.2 billion kilowatt-hours. The ten-year annual average for 1999 through 2008 was about 4.2 billion kilowatt-hours. The maximum annual net generation at Hoover Power Plant was 10,348,020,500 kilowatt-hours in 1984, while the minimum annual net generation since 1940 was 2,648,224,700 kilowatt-hours in 1956.

One thing to know…water as a fluid will always seek a level with itself. So, if you have water at one height on one side of a wall (like a dam) and lower on the other side, the water wants to flow down one side and up the other until it is level with itself. This is another factor in creating the head pressure.

Water Seeks Its Own Level

Water Power:

Conservation, Pollution, and treatment

Water as a natural resource seems really easy to take for granted because it is easy to find and there seems to be so much of it. Yet, the truth is that water is becoming an endangered species!

The water developed in the hydrologic cycle can meet the needs of only so many people. In competition for water against people are other factors, such as manufacturing facilities, farming, recreation, landscaping, and everyday needs such as bathing and washing clothes. Soon there may not be enough water to go around. Just look at your local paper to see the issues between the Farmers of the Valley and the ecologists of the Delta trying to protect fish. The battle is over water rights. So, each of us needs to find ways to conserve water in our own lives and not waste it or take it for granted. This is called “conservation” and it is a good thing for all of us to do.

Can you think of some ways you can conserve water at your home or school? How about other ideas to keep water from being wasted?

Water Power:

Conservation, Pollution, and treatment

Then, there is Pollution. This is where the good water we have in lakes and streams can get fouled from farm runoff, oil from streets, manufacturing waste, and human garbage. Pollution is a big problem, but it starts with each of us little people. Think about it—when you wash your car, where does the soap which goes out to the street and down the drains go? It usually leads to a stream somewhere and the soap can kill fish and pollute the water. Other types of pollution are harder to see—farm runoff can include pesticides, herbicides, and other nasty chemicals. Personal pollution can include people pouring oil from their cars down a street drain, leading to a creek where it coats the fish and frogs, and kills them. Manufacturing output can include heavy acids and chemicals, metals, and other poisons. While there are laws to prevent these pollutions from happening, they still occur. So, keep your eyes open and think about what you are doing when you are near water so you do not pollute.

Water Power:

Conservation, Pollution, and treatment

Human waste is one of the biggest users of water. The Sacramento Regional Wastewater Treatment Plant south of the city runs over 150 million gallons of water and sewage through its facility every day! The sewage comes in evil and dirty, but after it goes through the plant, the water coming out is pretty clean, except it has ammonia in it. The new plant expansion will add more facility to screen that out as well so the end result is water pure enough to drink! This is happening all over the world in different places, and it is needed, but you can see it takes an enormous amount of water to make it work.

Conclusion: Water is an abundant natural resource, which needs to be managed carefully to maintain the hydrologic cycle and ensure there is enough for all of us forever. For, without it, we will die within a few days.

Man has learned to harness the potential energy in water to provide mechanical and electrical power for the needs of civilization. Because of its abundance, water has been used by man for centuries to help build his cities and farms and light his homes.

Conclusion: Yet, without more effort, even this will go away. We are so very dependent on water for not only our bodies’ needs but also for electrical energy, that without it we cannot live like we do. But with good management, there should be enough for now and for hundreds of years to come.

Let us all think about how we use water and not waste it, making sure we have enough for future generations. And perhaps find even better ways to harness its power!