Benmore Dam is New Zealand's second-largest hydroelectric station, generating up to 552 megawatts of power, enough for about 298,000 homes.
Initially planned as a concrete dam like Waitaki, advances in earth dam techniques allowed Benmore to be built using earth, making it the largest dam in the Southern Hemisphere at the time.
The project spurred the growth of Otematata, where over 450 workers lived during construction.
In August 1958, the first shopkeepers arrived, helping develop the town.
The project also coincided with the construction of a power transmission cable across Cook Strait.
Benmore remains a key part of New Zealand's energy infrastructure and a significant engineering landmark.