It came from some sort of disturbance that created the wave. In most cases, the energy comes from wind blowing over the surface of the water. As the wind blows, it transfers some of its energy to the water, creating ripples and waves. The size and strength of the waves depend on the strength and duration of the wind. Other sources of energy that can create waves in a pool include the movement of objects in the water, such as boats or swimmers, and seismic activity. However, in the case of a pool, wind is the most common source of energy for creating waves.