Hesperian Health Guides

Small Dams

In this chapter:

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Water is taken from the river, run downhill to a turbine, and then flows back into the river.

Small dams can be used to generate electricity from running or falling water (called small hydropower, and micro-hydropower when it is very small). Where there is enough water from rivers or streams, micro-hydropower is the least costly way to provide electricity to rural communities. These projects can be set up and managed by villagers. In China,India, and Nepal, thousands of small hydropower projects supply power to villages and towns.

In small hydropower projects, water is channeled from a river or stream and runs downhill through a pipe. The falling water in the pipe turns a turbine, and then returns to the river or stream. Small dams do not displace people or change the flow of the river the way large dams do. Micro-hydropower projects use dams only a few meters tall to direct water toward the turbine.

Water turns the turbine
to produce electricity.
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(To learn more about micro-hydropower and to contact organizations that install micro-hydropower systems, see Other Environmental Health Resources.)

Micro-hydropower unites communities

As the country of Nicaragua recovered from many years of war, people throughout the country devoted themselves to rebuilding farms, water systems, schools, and health clinics. But the country was left in deep poverty, and the government was unable to provide electricity to many rural communities.

The village of La Pita had no electricity, and the nearest power lines were 70 kilometers away. People in La Pita had fought on opposing sides in the war, and this made it difficult to carry out community projects. But after they worked together to build a school and a clinic, they decided to bring electricity to the village as well.

The villagers asked a local group called the Association of Rural Development Workers-Benjamin Linder to help them electrify La Pita. Because the village lies close to a river that runs year-round, La Pita was a good site for a micro- hydropower project. The development workers helped the villagers organize the project and get support from a small international agency called Green Empowerment, which provided funds and technical skills.

Community members worked together for many hours to build the small dam and turbine that now send electricity to 400 villagers. The electricity is used in people’s homes, the community school, 2 carpentry shops, and local farms. When the electric plant was installed and running, the community formed an association to run and maintain the system, making sure everyone in La Pita benefits. Despite differences people had in the past, electricity and the responsibility for generating it is now shared by everyone. The small village of La Pita, far from the national power lines, has its own power.

People work together to build a dam.
This page was updated:05 Jan 2024