New Zealand Historic Places Trust Information Release
18 July 2008
Two early engineering feats which tell the story of Wellington's first
public water supply system have been registered by the New Zealand Historic
Places Trust.
Set within the natural environment of the Karori Wildlife Sanctuary 'a
world-first conservation attraction', the Lower Karori Dam, registered
Category 1, is an earth dam built across Kaiwharawhara stream between
1876 and 1878. It was the culmination of a number of attempts to bring
water to Wellington over the previous decade and today stands as the oldest
waterworks dam to be built by a municipality. Earlier water works dams,
such as Ross Creek, Dunedin, or in use in mining were privately built.
The distributing basin that was used in place of the dam until its completion
in 1878 has been filled in but remains beneath ground, while water from
present water supply systems still flow through the 1872 tunnel to Aro
Valley.
The dam was built using the puddle clay core earth dam technique, first
used in Britain in the 1760s and in widespread practice by the 1820s.
It was still used well into the 20th century. Working the clay was called
'puddling' and involved labourers in bare feet treading the clay with
water. The puddle clay core provided the waterproof element in the dam
wall. Also of interest are the valve tower and boat shed, utilitarian
structures which were finished to be aesthetically pleasing. The place
is set with ideal surroundings for others to learn about these early engineering
structures and the water supply system with significant features identified
and interpreted.
The Upper Karori Dam, registered Category II, was completed in 1908.
It is significant to the history of Wellington as a feature of the development
of the city's public water supply. The dam is set in a secluded part of
the upper south Kaiwharawhara valley, also part of the Karori Wild Life
Sanctuary. As the first large-scale concrete gravity dam in the country,
and an example of early use of concrete, the dam was considered an engineering
accomplishment of its time. It has remained virtually unaltered from the
time of its construction. The accessibility of the dam, together with
the archaeological features (including some reconstructed features such
as a cable tower and worker hut, and an assembly of worker equipment),
Rotary centenary projects from the combined Rotary clubs of Wellington
for the Sanctuary Discovery Area provide a great opportunity for public
education in early twentieth century dam-building practices.
The Upper Karori Dam was partially emptied in 1992 due to earthquake
risk following the commissioning of the Ngauranga Water Supply Pumping
Station. The dam was decommissioned in 1997.
For further information
Central Region Office
New Zealand Historic Places Trust
Tel: 04 801 5088
