In 1896, (after 40 years of resistance) the British Crown acquired the
Wairarapa Lakes from
Ngāti Kahungunu and in 1915, gave in return land in middle North Island, land known as part of the Pouakani Block. At that time the land where Mangakino lies today was described as native bush and pumice wastelands, barren, unoccupied and unfarmed. In 1946, as the Karapiro Dam neared completion, workers were to transfer to the next dam construction site – 'Maraetai I', near Mangakino. The Crown, under the Public Works Act, reacquired a portion of the unoccupied Pouakani Block alongside the Waikato River to build a "hydroelectric station" and a temporary township,
Mangakino, was established to house the hundreds of construction workers needed. The town was only ever meant to be there on a temporary basis until the completion of the proposed dams. The city planner
Ernst Plischke who emigrated from Austria in 1939 developed a plan for the town centre of Mangakino, which was put into action in 1947–1948. His plan included a pedestrian area in the town centre free from through traffic. In 1952 the population exceeded 5,000. Mangakino also serviced the construction of
Ātiamuri and
Ohakuri hydro schemes further upstream which were commissioned in 1959 and 1961 respectively. Mangakino and to a lesser extent
Whakamaru and Ātiamuri, owe their existence to the hydro schemes and the roads constructed gave access which allowed development of the land for farming in the 1960s. The decline for Mangakino occurred after the hydro dams were commissioned and over time communities such as
Maraetai and
Waipapa disappeared altogether. The marae was destroyed by arson in 2007 but reopened in 2012 after five years of reconstruction. In October 2020, the Government committed $4,525,105 from the
Provincial Growth Fund to upgrade Pouākani Marae and 9 other marae, creating 35 jobs. Miringa te Kakara Marae and Te Whetū Marama o Ngā Tau o Hinawa meeting house are a meeting place of
Ngāti Maniapoto and
Rereahu. ==Demographics==