Aratiatia is the first hydro
station and smallest hydro reservoir on the Waikato River. About 13 km
downstream from Taupo, Aratiatia is largely a 'run of river' station passing
water released from the Taupo Gates down to Lake Ohakuri.
The Aratiatia rapids are one of the river's outstanding scenic features.
Mighty River Power releases water down the rapids several times each day,
attracting more than 60,000 visitors annually. A road bridge across the top
of the rapids, tracks and viewing platforms, provide excellent vantage
points from which to see the rapids.
History
The potential of the Aratiatia
Rapids for electricity generation was first recognised a century ago.
However, because of their scenic qualities and the discovery of geothermal
activity at Wairakei, development did not proceed at this time. It wasn't
until 1954 that the government began investigating ways to use the area's
potential to generate electricity, while protecting the distinctive natural
features. This meant that Aratiatia was the eighth and second-to-last of the
Waikato River power projects to be completed.
Work began on the site in September 1959, and the lake was filled in March
1964 in time to forestall an expected electricity shortage.
For the power station to be constructed, the original channel at the top of
the rapids was plugged with earth and the water diverted into an open cut on
the riverbank where the spillway now sits. Unlike other power stations on
the river, there is no dam other than the earth plug and spellweir. This is
because the Waikato River falls sufficiently at this point to provide a
natural 'head'.
Nearly 750,000 cubic metres of material was excavated to provide sites for
the surge tank and powerhouse. The penstocks are buried in the area between
the surge tank and the powerhouse. A road now passes over these to the
powerhouse tailrace. Extensive landscaping and tree planting after
construction provides a very attractive setting today.
How Aratiatia got it's name
Aratiatia literally means a
series of pegs stuck into a steep ascent in a zig-zag pattern to make
climbing easier. It may also refer to the travels of the ancestral explorer
Tia of the Arawa canoe who made his way to these rapids while exploring the
Waikato River
Source: Mighty River Power