How to Invent a Dam #dam #engineering #hydropower #howitworks

Stones across a stream don't stop the water: it runs through the gaps. Clay seals them and a little lake grows, until it spills over the top and washes the wall away. Rebuild it with a stone spillway at the side, and extra water goes around the wall instead of over it. A bigger lake needs a taller wall, but water pressure grows with depth, so a thin wall cracks at the bottom. A concrete gravity dam is thick at the bottom and thin at the top, matching the pressure triangle. A pipe with a gate through its base lets the water shoot out with huge force, onto a Pelton wheel that drives a generator, and the village below gets light. Sources: hydrostatic pressure (p = ρgh), gravity dam and spillway design, Pelton turbine basics; details in the project notes.