This two part blog covers the Katse Dam itself and the road trip to the dam from the eastern Free State
The Katse Dam in Lesotho is one of the largest, and highest, in Africa, providing water for the densely populated Gauteng Province of South Africa. It is wedged in a narrow valley between mountain ranges reaching up to 3000 metres with daunting access problems prior to an approach road being tarred.
The double arch construction used 2,320,000 cubic metres of concrete for a wall 185 metres high and a crest length of 710 metres at 1,993 metres above sea level. The build took place at 6,000 m³ / day despite the long haul to bring in supplies. ‘Dead’ storage takes up about 430 million m³ leaving about 1,520 m³ which can be accessed at full capacity. The intake tower is 18 km from the dam wall, 23m in diameter and 98m high to enable it to draw off water at four distinct dam levels which allows the best quality water to be drawn off at any time. The tower has a 70 m3 / second capability to cater for the targeted eventual offtake in terms of the Lesotho Highlands Water Project.
The water from the dam passes through a 4m diameter tunnel, by gravity feed alone, to three 24 MW turbines at Muela close to the SA border (prior to which no commercial scale electricity was generated in Lesotho) and thence into the Muela Tailpond. The turbines can be bypassed to allow a constant feed of water to South Africa, for example during turbine maintenance, as a treaty requires. From here water can be diverted to the Caledon River when necessary but the great majority of the water is delivered to the Ash River outfall near Clarens, still via gravity feed and incorporating an uphill section at the end to reduce the flow speed and resulting erosion. From here the water flows via the Liebenbergsvlei and Wilge River to Vaaldam, the main source of Gauteng’s water.
The Road Trip to Katse Dam. Staying at the Wyndford Holiday Farm in this picturesque part of the eastern Free State, a stone’s throw from the Caledonspoort border post (below, looking into SA) it seemed as though it should be a pleasant couple of hours easy drive to the Katse Dam. Thus the advice that it might take four hours to get there came as something of a surprise.
The reason for the slow progress dawns on the traveller slowly. First there is the border to cross, with time taken on the SA and Lesotho side. Once in Lesotho adherence to the 50 and 60 kph speed restriction signs seems wise once one sees the ubiquitous mustard coloured taxis generally conforming and knowing that foreign cars are likely to be targetted. Once in the villages or towns speed slows to that necessary to traverse roads which would normally grace a building site. Whereas in SA it is necessary to avoid the occasional pothole here it can be case of avoiding the odd lumpy remnant of the road. We had been alerted to the fact that diesel would be significantly cheaper than in SA and that is true but then the jostling to get to the only pump in the main town we passed through does take the edge off that. Playing polo using cars must be a similar experience. In contrast to the rather chaotic nature of the larger settlements the houses along the rural roads put to shame those we are used to in SA. Down to the smallest little two room house they were attractively designed and strongly built and the larger ones were mansions.
It is only some way into Lesotho that the real mountains are encountered. The first pass, the Mafika Lisiu, tops out at 3,090 metres after what seems an eternity of climbing and after a similarly steep descent there is another pass before the dam comes into view. Crossing the dam by a bridge which is said to be the only significant stretch of straight road on the whole trip, can lead one to think the trip is nearly over but another pass has to be encountered before the dam wall is approached from the eastern side.
It has to be said that the road is in excellent condition all the way, especially bearing in mind the relatively few tarred roads in Lesotho. Thus it is an easy drive (I can’t speak for passengers!) given the terrain covered. The only problem of any sort encountered was a rockfall which covered slightly more than half the width of the road near the dam wall. Particularly engaging were the pack donkeys carrying goods, in the odd case not even accompanied by anyone but purposefully plodding along. This could not happen in SA as they would be hijacked within minutes, with the advantage of all terrain mobility for making an escape, especially as none had a “this donkey is under constant satellite surveillance” sign. One can only hope that these animals are not stolen for the international trade in donkey skins which in some parts of Africa has left villagers without the means to transport goods, water or people. One wonders how many of Africa’s animals have to be slaughtered in the pursuit of products such as rhino horn or elephant tusks. One of the products of donkey skins is the Chinese medicine ejiao.
The main visitor complex provides a good view of the wall but the more interesting experience would be to go into the heart of the wall. Unfortunately the next tour was some way off and we were conscious of the long drive back. The pictures below are ours, taken in the current drought, and a Lesotho Tourism file photo when the water level was higher.
Lunch was therefore taken in the Katse Botanical Gardens whose origin arose from the realisation that some rare plants would be further endangered by the dam project, in particular the spiral aloe. The gardens do not appear to be overly well maintained but good work has been done by way of propagation and in the greenhouses rather than in the open. Plants were not the only casualties. People were displaced and the International Rivers NGO produced a report detailing their trials and tribulations. A number of convictions followed corruption. The land itself felt the effects, presumably earth tremors, from the weight of water induced seismicity.
The drive back involves less climbing, by virtue of the dam being about 500m higher than the border post but I set my Garmin eTrex to measure the total ascents and descents and based on this the total climbing for inward and outward journeys combined was 7,510m. That is quite a round trip for carrying in thousands of tonnes of construction material every week. Encountering people who had been involved in the logistics indicated that this took place without a single accident. Total truck kilometres amounted to 7.2 million, which without trying to perform a calculation, sounds like pretty big trucks being used. While our round trip was about 320km the trucks started from Ficksburg, making it more like 400km.
Sources: Wikipedia; golesotho.co.za; The Guardian
© J R B Livesey 2017