Miyagase Dam, Concrete gravity dam in Kanagawa, Japan

Miyagase Dam is a dam in Kanagawa Prefecture, Japan, blocking the Nakatsu River. The concrete wall rises 156 meters and the reservoir behind it holds up to 193 million cubic meters of water.

Construction began in 1971 and lasted until 2000, as 300 households had to be relocated. The government chose this method to provide drinking water for the growing population of the region.

The name Miyagase comes from the village of Miyagase in Kiyokawa, one of the three municipalities the dam spans; 300 households were submerged and 1,136 people relocated. Sightseeing discharges run from April to November on Wednesdays, the second and fourth Fridays and the second Sunday, sending water from gates about 100 metres up the face for four minutes at 11:00 and 14:00. In December a Christmas tree is lit on the lakeside.

The dam sits about 50 kilometers from Tokyo and is reachable by car or bus. A visitor center near the shore provides information about how it works, and there are viewpoints where you can see the wall.

The dam's crest carries an incline railway, a cable car that is not a licensed railway under the Railway Business Act, linking the top of the dam with the area directly below and Aikawa Park. The reservoir, Lake Miyagase, was named one of Japan's 100 Dam Lakes in 2005 on the recommendation of Kiyokawa Village.