The winds that hit Mt. Unzen from the west develop rain clouds, and the rain from these clouds provides abundant water to Chijiwa River. A local wealthy person took notice of this large volume of water resource and built a hydraulic power plant here. It was the New Year's Day in 1910 when the first electric light in the Shimabara Peninsula was switched on. This power plant is still supplying electricity to the Chijiwa town today.