Urban water supply
Johannesburg – City on a watershed
18 The Water Wheel May/June 2011 Urban water supply
Johannesburg’s location is both its gift and also a metaphorical one – changing sprang up to house the thousands of its curse – close to the gold, but far from from a water-secure to a possibly people seeking their fortune. water insecure city. Originally, water was drawn from water. Article by Petro Kotzé. the Fordsburgspruit, as well as from Small beginnings a spring at the eastern end of Com- ohannesburg’s location is both missioner Street, near the present its gift and its curse. On the one ohannesburg is situated on a day End Street, called Natalspruit. hand, the gold-bearing reef that Jdivide between the Vaal River Another water point was a spring at isJ the reason for its existence has catchment (the Vaal itself being a the site of the present Johannesburg shaped it into the economic heart- tributary of the Orange River) and general hospital in Parktown. With land of the country. On the other the Limpopo River catchment. On the expansion of mining activities, hand, it is one of the few cities in the one side, water runs down the Vaal industrial development, pollution world not located close to one of the and the Orange towards the Atlantic, and population growth, the demand most important resources necessary while on the other side water drains for potable water grew. Soon, the to sustain its growth: water. towards the Indian Ocean via the rivulets and boreholes were inade Indeed, where other major cities Limpopo River system. quate sources of supply. Eventually, in the world have developed close to The city straddles this major the need arose to bring water from rivers, seas or other water sources, watershed, known as the Witwa- the Vaal River. the Witwatersrand metropolitan tersrand, and the discovery of gold The Vaal River scheme (1914- area has been described as one of the in the conglomerates (sedimentary 1924) was to be developed in phases. largest concentrations of people so rock consisting of peddles and sand The first phase would involve the far away from one. The nearest river grains cemented together) underly- construction of the Vaal Barrage, of any significance, the Vaal, is about ing the area during the 1880s was the a purification and pumping works 70 km away. catalyst for its development. The area at Vereeniging (1924), a pipeline to Since gold was discovered on the was named after the pristine springs Zwartkoppjes Pumping Station, and Rand in 1886, the once dusty mining and small streams that occurred pipelines to Village Main Reef and town has grown into a metropo- along a ridge some 380 m above elsewhere in the distribution system. lis that houses a quarter of South the surrounding country, in the The Barrage, deriving water from Africa’s population and is responsi- southern parts of Gauteng, striking the Vaal River and the four tribu- ble for about 10% of the continent’s westward in the North West prov- taries, would be capable of yield- economic activity. As the city has ince. It refers to an area stretching ing 91 Mℓ/day. The Vaal Dam was grown in size, however, so has its between Springs in the east and the completed in 1938 (with a yield of thirst for water, with formidable con- Krugersdorp/Randfontein area in 354 Mℓ/day) followed by the Zuiker- sequences for its bulk water supplier the west, a distance of about 90 km. bosch pump station in 1949. – Rand Water, established in 1903. Shortly after gold was discovered, a The first inter-basin transfer from Today, the bulk of the water supply conglomerate of camps and shanties a river basin outside the normal is pumped from the Lesotho High- lands, through a system of intercon- nected water sources, pumps, valves, pump stations, purification plants, pipelines of various diameters and reservoirs. This growth has put increas- ing pressure on both the quantity and quality of water available while, according to Rand Water, the increas- ing volume of people in need of water and sanitation services is a mounting concern. Looming mining applica- tions in the catchment of the Vaal Dam and the possible effects of cli- mate change add further force behind future water supply problems. This The Vaal Dam, constructed in the 1930s, puts the City of Gold in a precarious remains the centre of position, not only located on a physi- Rand Water’s supply
cal watershed, but according to some, infrastructure. Lani Vuuren van
The Water Wheel May/June 2011 19 Chris Kirchhoff-mediaclubsouthafrica.com Chris Urban water supply
Today Rand Water supplies water through about 3 056 km of pipeline into 58 reservoirs. Courtesy Courtesy Rand Water
catchment of the Vaal system was and Zuikerbosch Purification and to population growth rates, with announced in 1970. The plan was to Primary pump stations. It is then economic growth playing a second- supplement water using the Thukela pumped at a head of about 180 to ary role. River in KwaZulu-Natal by pump- 360 m to the main booster pump sta- According to information sup- ing water over the Drakensberg tion, Zwartkopjes and its three satel- plied by Karl Lubout, water qual- into the Vaal River catchment and lite booster pump stations, Palmiet, ity specialist at Rand Water, even other inter-catchment transfers Eikenhof and Mapleton. though Rand Water’s current catch- (the Thukela-Vaal Augmentation Each booster pump station then ment area largely comprises rural Scheme). elevates the water a further 180 m to agricultural area the towns in the Currently, the bulk of Rand 360 m to reservoirs in and around catchment are growing rapidly. How- Water’s water supply comes from the Johannesburg. From these areas the ever, proper infrastructure is lagging Lesotho Highlands. The scheme was water flows under gravity and is behind and the volume of people in designed to deliver some 2,2 x109 of re-pumped at distribution stations to need of proper water and sanitation water annually to South Africa, and the extreme boundaries of the sup- services exceeds the service delivery the first water flowed into the Vaal ply area. capacity. “The lack of proper sanita- Dam via the Ash River outfall on 8 The water is supplied through tion services in our catchment area, January 1998. about 3 056 km of pipeline into 58 especially, is of great concern to us,” reservoirs (two-thirds of the value of says Lubout. Intricate system this infrastructure, estimated to be With regards to the impact of worth R30-billion, lies underground acid mine drainage, Lubout indicates rom small beginnings in 1905, in pipelines). Water is then delivered that it does not currently have an Fsatisfying an annual daily in bulk from the reservoirs to Rand influence of Rand Water’s service consumption of water of about Water’s customers. delivery. Of more concern is the cur- 11 Mℓ/day, Rand Water today oper- In the early days, mining activi- rent number of mining applications ates a massive water supply system. Of ties gulped up most of the water. around the Vaal Dam area. “If these course, the water utility’s operations This has evolved over the decades, applications are approved it will have expanded way beyond Johan- in tune with the changing face of certainly have a negative impact on nesburg – as far as Rustenburg in the Gauteng, and it is believed that about the quality of our raw water.” west and Groblersdal in the east. 70% of the water is now supplied to Population and economic growth Water is abstracted from the Vaal urban domestic consumers. Thus, rates are not the only factors influ- Dam and treated at the Vereeniging demand growth is now closely linked encing the future of Rand Water’s
20 The Water Wheel May/June 2011 Urban water supply
water supply, broader scale global increased water purification cost. influences, such as global warming, An added burden as a result of The unwanted city are also at play. climate change could be that the he first piece of Johannesburg was Rand Water supply area can become a triangular piece of uitvalgrond Climate change more conducive to the transmission T of waterborne diseases. “Combined called Randjeslaagte between the ith regards to the effects of with the free migration of people farms of Braamfontein, Doornfontein Wclimate change, in general, from northern countries, this could and Turffontein. Uitvalgrond refers the overall burden on the country become a major problem,” says Van to ‘left-over’ property between the will be disaster management costs, Wyk. In addition to additional stor- borders of claimed farms. These auto- says Francois van Wyk, water quality age, flood attenuation measures will matically belonged to the state as none expert at Rand Water. As an exam- need to be implemented, which will of the farmers laid claim to it (often ple, he cites the floods in Mozam- also be unused during dry peri- because it was unsuitable for agricul- bique in 2000 which reduced that ods, while the possibility of severe ture due to a lack of water). That tiny floods could cause major damage to country’s annual growth rate from area, just big enough for a village, was infrastructure. 8% to only 2%. “Should such inci- to become the biggest city in South dents occur more frequently, poorer According to Van Wyk, pressures Africa within three decades. countries will suffer massive social on supply from Vaal Dam could Traces of Randjeslaagte can still problems. The ultimate consequence lead to the Department of Water of climate change is a substantial Affairs insisting that Rand Water use be found around Johannesburg. The additional burden to the country’s a higher proportion of water from northern point is just off the corner of economy, with obvious restraints on the Vaal Barrage, where water is of Boundary Road, Parktown, and Louis Rand Water’s financial position.” an inferior quality. This will mean Botha Avenue, close to Clarendon Circle. The predicted increase in that water treatment plants will have A triangular monument marks the spot. extreme weather events, as well as to be adapted to be able to treat this The south-eastern corner is at the possible prolonged periods of high water adequately. intersection of Market and End Streets. (maximum) demand as a result of This situation could eventu- The latter is so named because it marks ally result in the Clarens pipeline higher temperatures, are some of the eastern boundary of Randjeslaagte. becoming a reality, as no losses of the pertinent issues with regards The eastern side of the triangle runs up to climate change which Rand water due to unlawful use (as is the hill along Catherine Avenue (adja- Water will have to pay attention to. currently occurring) or evapora- cent to Nugget Street) and through Current inter-basin transfers may tion can be afforded. The Clarens become areas of political conflict, to Johannesburg pipeline would Hillbrow, meeting the top at the corner elaborates Van Wyk. “If a severe involve constructing a pipeline to of Banket Street. water shortage occurs in the area, gravity feed the water from the The south-western corner is at Lesotho may not want to release transfer tunnel outlet near Clarens the intersection of Commissioner and water to South Africa, or they northwards to Gauteng. It would Diagonal Streets. Just off that corner may want to enforce substantially include the construction of a stor- is the start of West Street (so named increased tariffs.” age dam and a new water treatment because it marks the west side of the Since gold was Furthermore, Rand Water will works located on relatively high discovered in 1886, the triangle). West Street curves inwards ground in Gauteng. have to address and optimise overall once dusty mining town and aims straight at Hillbrow’s Prof Anthony Turton, water energy efficiency. Due to erratic of Johannesburg has Clarendon Place, which marks the rainfall patterns, security of supply resource management scientist, grown into an African apex of the pyramid. will also be at risk. “This may imply believes that Johannesburg has powerhouse. that storage capacity needs to be increased to store more water if and when it rains, while dams and res- reached a watershed moment, and ervoirs may be empty for prolonged that a limited water supply would, in periods of time,” causing inefficient turn, also limit economic develop- use at high cost. ment. “We have reached the end of Higher temperatures will not our available water supply and have only increase evaporation from arrived at a new future: that of water dams (and so increase water loss), it recycling.” Prof Turton believes that may also lead to the occurrence of the answer lies in giving scientists algae during periods of the year not and researchers the freedom to previously experienced, resulting in Chris Kirchhoff-mediaclubsouthafrica.com Chris explore possible solutions.
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