A hydroelectric dam
Some dams store water that can help generate electricity.

Picture in words: 1. Reservoir: Water is stored behind the dam, higher than the water below.
2. Intake: Water flows downhill through a pipe called a penstock to a turbine at the base of the dam.
3. Turbine: Water turns the turbine blades inside the flow passage. A straight shaft connects the turbine to the generator above.
4. Electricity: The generator above the turbine makes electricity. Water leaves through the outlet below and flows downstream.

One more wonder: Not every dam generates electricity. Dams can change river habitats and fish journeys.
Stay away from spillways and fast-moving water; visit only permitted areas with an adult.

Question: What turns the turbine?
Answer: Moving water

Sources:
EIA: how electricity is generated — https://www.eia.gov/energyexplained/electricity/how-electricity-is-generated.php
US Department of Energy: how hydropower works — https://www.energy.gov/cmei/water/how-hydropower-works

Reviewed 28 September 2026. Simplified educational illustration, not to scale.
https://atherverse.com/kids/how-things-work/dams/