KARĀPIRO HYDRO STATION
The Karāpiro Hydro Station is located 188km downstream from Lake Taupō.
The Karāpiro Hydro Station is the last station on the Waikato Hydro System and is located 188km downstream from Lake Taupō. The Karāpiro Lake is the home of NZ Rowing.
Karāpiro is a concrete arch dam carrying a single lane road along its crest. The dam is 335 metres long and 58 metres high. Three penstocks convey water from the intakes to the Kaplan turbines in the powerhouse below. The water then flows back into the Waikato River 30km upstream from Hamilton City.
Each of the turbines have a generation capacity of 37.5MW – making the stations total capacity 112.5MW. The average annual output of the power station is 537GWh – that’s enough electricity to power the equivalent of 63,000 average homes a year.
HISTORY
The Karāpiro Hydro Station was one of nine constructed on the Waikato River from the 1920s through to the 1970s as part of a Government programme to firm up electricity resources for a national power grid.
Construction of the Karāpiro Hydro Station commenced in 1940 and was delayed during World War II, finally being completed in 1947 with commissioning of the three Kaplan turbines occurring in 1947 / 1948.
Click here to view a more detailed time-line.
Click here to read the Māori history of Karāpiro.
In the 2010’s we began a multi-year programme to refurbish each of the hydro stations on the Waikato so that the system could continue to supply electricity to the country for many more years to come.
We started with upgrades to Arapuni, our oldest hydro station on the Waikato River, and then we moved on to refurbish Ōhākurī, Whakamaru and Aratiatia hydro stations through to 2020. Click here for more information.
KARĀPIRO REFURBISHMENT– 2019-2025
In 2019 we began a $90 million upgrade of the station. This work involved replacing all three of the turbines with modern equivalents. The new components we installed improved efficiency by about 5%, allowing us to generate more power from the same volume of water.
It means Karāpiro now has an additional 16.5MW, taking total installed capacity from 96MW to 112.5MW.
That increases its average annual output by 32GWh, enough to power the equivalent of an extra 4000 average homes.
The hydro station’s total average annual output is now 537GWh, producing enough electricity to power the equivalent of 63,000 average homes a year.
We completed the project in September 2025.
Click here to read more.
VARIOUS MEDIA ABOUT THE REFURBISHMENT
15 May 2021 – Multi million dollar refit – Stuff 25 August 2022 – One of the biggest hydro upgrades – Cambridge News 10 May 2023 – Early look at dam – Cambridge News 18 July 2024 – Another milestone reached – Cambridge News 12 April 2025 – Flow-stopper: river icon gets a do-up – Waikato Times 21 August 2025 – Karāprio reunited – Cambridge News 21 August 2025 - Karāpiro celebrates as Hydro Station upgrade nears completion - Mercury 25 September 2025 – Project Milestone – Mercury