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The Orange-Fish Tunnel

The Great Fish River as it is today.

The Great Fish River as it is today, flowing past Oukop hill outside Cradock.

By Julienne du Toit. Photographs by Chris Marais

Up until 1976, the Great Fish River was very different to the cappuccino-brown fast flow that it is today.

The Fish River Canoe Marathon would never have been possible without the Orange-Fish Tunnel.

The Fish River Canoe Marathon would never have been possible without the Orange-Fish Tunnel.

Farmers living alongside its banks and Cradock residents had to cope with an unpredictable and seasonal waterflow. During rains it flowed clear and broad. In winter it dried up to a series of green puddles. The Eastern Cape Midlands had so much promise because of its rich arable soil, yet its potential remained locked away for lack of water.

But the building of the Gariep Dam changed all that. Once it was finished in 1971, the dam waters were available for irrigation. But first it was necessary to link the Great Fish River to the dam and to do that, a very long enclosed aqueduct had to be dug through the Suurberg Mountains.

This was a project that needed highly specialised engineering, so the South African government of the time sought out experienced and junior engineers from England, Portugal, West Germany, France, Belgium, Italy and Spain to help with the design and construction.

The mighty Gariep Dam, all its sluice gates open during heavy rains.

The mighty Gariep Dam, all its sluice gates open during heavy rains.

A French, an Italian and a South African team all worked simultaneously on lengths of the tunnel. Even the curvature of the earth was taken into account when setting out the levels.

The miners dug through mudstone, ironstone, sandstone, and lethally explosive pockets of methane.

Most people have forgotten the staggering human loss. No fewer than 102 people died building this tunnel, many of them from foreign lands.

When the tunnelling teams met one another in 1975, they were less than 4mm out of alignment.

Teebus and Koffiebus, two distinctively shaped hills near Middelburg.

Teebus and Koffiebus, two distinctively shaped hills near Middelburg.

At just under 83km, the Orange-Fish Tunnel is the world’s third-longest aqueduct, ending at the distinctive hill called Teebus between Middelburg and Steynsburg.

Here, a quarter of the Gariep Dam’s waters pour into the Teebus Spruit, which flows into the Brak River, and then into the Great Fish. Further south, the there is a link into the Sundays River via a canal near Somerset East.

Orange-Fish Tunnel

The entrance to the Orange-Fish Tunnel.

  • For 5 or 6 weeks during June and July, the tunnel is emptied for inspection and maintenance. During this time members of the public are welcome to have a look at the tunnel, and even drive through a circular part of it. Because methane levels can rise, only diesel vehicles are allowed. The tunnel is also never completely dry, and anyone wanting to explore it should bear in mind there will be darkness, confined spaces, splashing fish and the odd crab. Bring gumboots.
    To organise a visit, call Lettie Dipenaar on 051 754 0001/2.
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2 Responses to The Orange-Fish Tunnel

  1. Roslyn Lindley (@RosnDavid) June 10, 2014 at 6:31 am #

    Would like to add it to my Karoo list. Got to keep visiting that Big Karoo Space and keep on visiting on and on and on. Never knew we could actually do this, with or without gumboots. xx

  2. cleansing balm September 13, 2014 at 6:06 pm #

    Right away I am going away to do my breakfast, after having my breakfast coming over
    again to read more news.

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