Hydroelectric Power is Generated from Water But...

Making electricity from water may sound strange but that's exactly what hydroelectric power works.

There is a lot of energy created by large bodies of flowing or falling water. Water naturally follows the force of gravity and it is that that explains hydroelectric power and how it works.

Huge dams allow water to rise to new heights as the flow of streams and snowmelt come down form the mountains. The power of the water as it is released from the dams through sluices and gates is sufficient to turn turbines and generate electrical energy.

Some hydroelectric plants use the natural flow of a large river and dams are not necessary. In others areas, even smaller streams of rapidly flowing water can be harnessed to turn small generators an product electricity.

Benefits and Disadvantages

One of the big benefits of hydropower is that is a renewable source of clean energy. Fuel is not required so there are not pollutants of greenhouse gases produced in the process. Currently about 20% of the energy worldwide is provided through hydroelectric power generation.

One problem associated with how hydroelectric power works is the problem of building huge dams. Damming a river can have unforeseen consequences. This was proven many years ago when some of the huge dams in the U.S. were constructed.

Dams interrupt the natural flow of rivers and streams and this can lead to fish kills and to other problems for fish and wildlife. Changing the natural water flow affects the land and wildlife both above and below a dam.

Often dams require relocation of people in areas where land will be flooded by the water that pools just above the damn. This affects migrations of fish to spawn and the watering holes of wildlife.

It can also affect water for irrigation of farmlands below the dam. In the U.S. huge dams such as the Hoover Dam were built before there was public concern for changes that could negatively affect natural ecosystems.

Many of the concerns abut hydroelectric power today are a result of real problems that appeared after the country built several large damns and hydroelectric power plants. The cost of build large dams is a problem today but also the areas that are naturally suited to dam construction are limited.

Understanding how hydroelectric power works leads to the realization of the dangers that can be present in towns and cities located below the dam. The environmental disruption of a large dam is a concern but the danger of living below a huge dam is very real.

A small earthquake, poor materials used in dam construction or lack of maintenance can cause a dam to fail and allow massive flooding in towns and homes located downstream.

The rushing water has the strength of a tsunami and can cause massive destruction of property as well loss of live for people and livestock.

How will Hydroelectric Power Work in the Future?

Hydroelectric power plants are amazingly efficient. They do not produce pollutants but do have other negative effect on the environment unless development is carefully planned.

There is little chance of expanding hydroelectric power due to the very real concerns about environmental damage. Fish are prevented from moving naturally up and down stream which was a problem for spawning salmon.

However, that is only one small example. Building a dam turns a river ecosystem into a lake ecosystem. You may think this is still just a body of water but that is not the case.

The wildlife in or near a river depends on the flow of the water while lakes block migration, prevent spawning and reproduction and can result in the elimination of species. Hydroelectric power created through a system of dams results in flooding of hundreds or thousands of acres of land.

This requires relocations of farms and small towns and often floods land that was extremely fertile and productive. Small wetlands are often swallowed up and thus yet another tiny ecosystem is destroyed.

One unforeseen problem has been the leeching of metals into the water trapped behind a dam. If land and rocks have mercury in the composition flowing water of a river would not have the same effect as flooding the area with standing water that allowed the metals to be released and build up in the water supply.


We know how hydroelectric power works and experience has taught us the pros and cons of this renewable energy source. In spite of environmental problems caused by huge dams, hydroelectric power is clean and plentiful. Once a power plant is established it is cost effective to maintain.