The Mokopeka Station Power House, installed by John Chambers in 1892, is a monument to the early and innovative use of electricity in this country. It is believed to be one of the oldest continually operating hydroelectric plants in the world. John Chambers (Jnr.) was born in New Zealand in 1854 not long after his parents and siblings had emigrated from Australia. His father John Chambers (1819-1893) had left England for Australia in the late 1840s. John Chambers (Snr.) married Margaret Wills Knox in 1848. After a period working as a blacksmith on the Victorian gold fields, Chambers decided to seek further opportunities in New Zealand. Following a preliminary visit in 1853, Chambers returned to New Zealand with his family in March 1854, and settled in Hawke's Bay. Here through a combination of purchasing land from the Crown and leasing land from local Maori, Chambers established a large sheep run centred on Te Mata. Chambers was also an avid inventor and in 1881 he went to England to promote a method of freezing meat which he had devised. He was not successful. He returned in 1885 and in the following year he retired and split the now 7284-hectare (18,000-acre) station into three portions for three of his four sons. John (Jnr.) was given Mokopeka Station (2631 hectares or 6500 acres) at Maraetotara.

John Chambers (Jnr.) like his father had a keen interest in engineering, and had studied mechanical engineering from the American School of Correspondence, Chicago. In December 1891 he began the construction of a private hydroelectric station at Mokopeka. Chambers ordered a 14 horsepower Victor Turbine and a 8kw -110 volt DC dynamo from his London Agents. The latter was a second hand dynamo that had first been used at London's St Pancreas Station in 1886. He then built with the help of his station hands across the Maraetotara River, a dam, powerhouse, and 200-metre headrace. The first electricity was generated on 21 September 1892. The power station provided enough power to electrify the shearing shed (Category II Historic place), and eventually the whole farm and a neighbour's property.

In the previous year Chambers had installed Hawke's Bays first telephone with a line from Mokopeka to his brother's farm at Tauroa. Later he invented the first electric stove in Hawke's Bay and designed electrically driven hand pieces for his wool shed. Chambers along with his brother, T Mason Chambers, Hugh Campbell, and George Nelson, founded the Hawke's Bay Tribune in 1920.

In about 1926 the original generator was replaced by a new Swedish 17KW DC generator. To accommodate the new generator the roof of the generator building was raised. Following John Chambers death in 1945 the family continued to utilise the generator, until finally in 1965 a series of droughts forced them to join the national grid. The hydroelectric station, however, was kept in working order. In 1969 the maintenance of the station was taken over for a time by the Hawke's Bay Electric Power Board as a 'vintage project'. In 1990 the Mokopeka hydroelectric station was recognised by the Institute of Professional Engineers with a plaque placed near the site. Today the power station remains in the ownership of the Chambers family. It is used to supply electricity for heating the nearby homestead and during the summer months lighting a restaurant/functions venue that has opened adjacent to the powerhouse.

The Mokopeka Station Powerhouse (including race and dam) is one of New Zealand's outstanding private engineering achievements. It is a unique example of the early and innovative use of electricity in New Zealand, and is believed to be one of the oldest continually operating hydroelectric plants in the world. The powerhouse was assembled by John Chambers, a successful farmer and inventor, and a member of a notable Hawke's Bay family. Located on the banks of the Maraetotara River, the powerhouse and tailrace blends well into its natural setting.