The Craig Goch Dam, often called the Top dam, is a masonry dam in the Elan Valley of Wales and creates the upper-most of the Elan Valley Reservoirs. Construction on the dam began in 1897, and it was completed in 1904. The primary purpose of the dam and the other reservoirs is to supply Birmingham with water. In 1997, a 480 kW hydroelectric generator began operation at the dam.