Tiki-Tour: Part 5
Created | Updated Apr 8, 2012
5: Clyde
To and At Cromwell
From Te Anau, the day after our Manapouri power station visit (see part 4), it was a 215km (130mile) drive north again, this time to Cromwell for the night, before going on to Clyde.
Cromwell was once called "the junction" because it lay at the confluence of two rivers, the Clutha
and the Kawarau but now, though situated at the same geographical spot, it is on the south shore of
lake Dunstan – an artificial lake created for the Clyde dam.
Cromwell's beginnings were as a gold-rush town (in company with Clyde) and is now known for
its stone-fruit growing (the fruit-bowl of the south).
When the lake was created about one third of the town was relocated to higher ground while the
old town centre is preserved, making an interesting place to visit, housing as it does several artists'
premises, to while away a pleasant hour or two, while nearby a plaque points you to where the old
bridge that used to cross the Kawarau River still is, 10m (33ft) below the surface of the lake.
The main reason for us being there on this occasion was Clyde. We'd been there before, a few years
ago, but wanted to refresh our recall.
Clyde
Clyde was the scene for a gold-rush (the same one as Cromwell) in earlier days, while now it, too, is
known for its stone fruits and its Pinot Noir. The dam, though, is perhaps its centre of attraction.
The dam is one of the products of the Think Big era, introduced by prime minister Robert
Muldoon (1975-84), in response to rampant inflation caused by the 1970s energy crises, combined
with the loss of probably the country's biggest export market, when Britain joined the European
Economic Community. With the country in trouble, the idea was to set up for the future, thereby
(hopefully) lessening the effects of future such crises.
Highly controversial at the time, this project was the cause of closure of the Otago Central Railway
further on from Clyde (but provided work for the remaining portion). The dam is still despised by
some as an example of political ambition overriding common sense, as Cromwell was apparently
set to become a major tourist centre due to its dramatic landscapes (the Clutha and the Kawarau
river gorges, now largely flooded).
In an attempt at mitigation, a low dam had been proposed but the following government
(Muldoon's) overrode that, bargained away other obstacles and a high dam was built.
Early-on in the construction, a problem arose: it was found that an earthquake fault runs along
the river, under the dam site. A redesign ensued, requiring a slip-joint to be built-in that would
accommodate up to two metres of ground movement. In the event, the dam consists of 1,000,000
cubic metres of concrete in two parts, with the slip joint between.
The surrounding rock was found to be micro-fractured, so cement slurry, in large quantities, was
pumped in to stop leaks – subsequently, preventative measures meant that there are 18km (11miles)
of drainage tunnels in the gorge to alleviate water pressure build-up.
It is now the third most powerful Hydroelectric generating station in the country, at 432MegaWatts,
following Benmore (540MW) and of course Manapouri (730).
With its four turbines, it is capable of generating 480MW but runs at that lesser level due to
environmental restrictions. It was built to accommodate two more turbines, but there wouldn't be
enough water to drive them.
Having started in 1982, filling it began in 1992 by submerging much of the gorges, creating Lake
Dunstan and flooding that part of Cromwell. The project was completed in 1993 after an overspend
of some 50%.
A better description of the dam problems (from the objectors' point of view)
can be found here.
After all that, it works, and, was the last of Muldoon's Think Big projects.
Onwards, again
This time (next episode) to Oamaru via Palmerston, another long drive – which is a reminder...
On the way to Cromwell (on the day before this Clyde visit), we had encountered a house on the
road. No, not a horse, a house. The first we knew of it was shortly after we'd been directed onto
a picnic area – the lead car with a large sign atop saying, in less than friendly manner in black on
yellow, HOUSE FOLLOWS.
The whole carriageway just wasn't wide enough on these mountain roads, methought, but there it
came, in stately motion, going I know not where.
The other sign, at least as large but facing backwards (yes, backwards), on top of the lorry following
it, said in larger, somewhat friendlier, black on green letters, HOUSE AHEAD – and the number-
plate of the trailer carrying the thing said OVERSIZE.
We waved but no-one came out with a cup of tea.
