This photograph shows part of the Mangahao Dam construction site, a crane can be seen in the background and what appears to be a steel reinforcing wall below the concrete dam. The Mangahao Power Station provides hydroelectric power and is situated near the town of Shannon. It serves Wellington, Horowhenua, Taranaki, Hawkes Bay, and the Wairarapa. After being delayed by the first world war construction began in late 1919 and the station opened in November 1924.