Why water is power
Everybody knows just how important water is; we obviously can't survive without it. However water is far more important than just as something to drink. Water is also our major source of power. We would have no electricity without water. Unfortunately it is getting harder and harder to use water as a power source because of the environmental impact that it has. We are going to have to find a way to compromise on the need for power and the need to protect the environment.
Water is power because it has so much energy which can be exploited for our use. It should be obvious just how much power water has when you look at the Grand Canyon. This was formed entirely by the power of water. As water flows it erodes the earth and completely changes the landscape. It didn't take people long to realize that they could take advantage of this power and use it for their own benefit.
The first use of water as a power source by people was the use of water wheels. These were simple wheels that were placed in a river so that the flow of water would spin the wheel. The early water wheels were used primarily for grinding grains but they could also be used for other things like running the first power tools. As water flows it has a tremendous amount of energy so there is a lot of power available even from the flow of a small creek.
The development of electricity made water even more important as a power source. It was quickly realized that one of the easiest ways to generate electricity is to use the flow of water to spin a turbine. This is really just a more advanced version of the water wheel. The early form of hydroelectricity just used the flow of water directly from rivers. However these days dams are usually built so that the amount of water that is used to spin the turbines can be regulated.
Of course water has power for other reasons than its flow. Water is also a great store of energy. Steam engines for example operate by heating water so that it becomes steam. The expansion of the water then pushes on a piston. Power plants that operate by burning coal or by nuclear power both work by heating the water so that it becomes steam and then allowing the steam to spin a turbine.
There is also some work being done on using the chemical properties of water as a power source. The reaction of water as it breaks down into its components or when it combines with other molecules causes the release of energy that may be used as a power source. These are still areas of experimentation but there is progress being made. Water is critical to almost all of our power sources and that is unlikely to change any time in the future.