5 Environmental Impacts of Hydropower


Hydropower is often considered to be an alternative energy and renewable resource. This is because the power of falling water can create movement that turbines can collect and then distribute for power. From an environmental perspective, most hydropower facilities do not pollute locate water supplies or put emissions into the air.

That’s the good news. The bad news is that there are several other environmental impacts of hydropower which must be considered.

1. Most Hydropower Is Collected Through Damming.

Dams are built on waterways as a way to create hydropower. This means a reservoir naturally develops behind the dam as water collects. These reservoirs can be used for irrigation, flood control, and even recreation, but they will also displace habitats and can force whole communities to be displaced. For the High Aswan Dam project, more than 120,000 people had to be moved – some up to 700 kilometers away.

2. It Creates a Flooding Threat For Downstream Communities.

In the US, most dams were built to control flooding. This created reservoirs which also offer an ongoing flooding threat should a dam break for some reason. The devastation from a sudden flood from a dam is on a much higher scale than most seasonal flooding could every cause.

3. Hydropower Can Obstruct Fish Migration.

This effect has been especially harmful in the Pacific Northwest. When fish are unable to migrate, then they do not reproduce on the same scale. Migrating fish are also a major food source for many animal populations. Fish ladders and similar technologies can help migrating fish bypass a dam, but it only takes one season for the damage to be done.

4. It Changes The Water Chemistry Of a River.

Dams are known to change natural water temperatures, alter silt loads, and change flow characteristics. This can have a positive or negative effect on local wildlife populations.

5. Emissions May Be Released.

Most dams are built through a combination of concrete and steel. The manufacturing of these items releases emissions into the atmosphere that may contribute to the global warming process.

The environmental impacts of hydropower are often physical in nature, which means there is an ongoing cost to pay for this renewable resource. That’s why each community must decide if it is the right type of power to utilize.