Botswana’s North-South Carrier Water Transfer Scheme a strategy for ensuring economic growth INTRODUCTION Increasing mining activities and an ex- panding population in eastern Botswana mean a growing demand for water. Th is need has been anticipated by the Botswana government, and its long-term strategy is now facing its second phase with the development of the North- South Carrier water transfer scheme Francistown by the country’s Ministry of Minerals, Energy and Water Resources (MMEWR). Shashe dam Dikgatlhong dam Leading infrastructure development fi rm Shashe river PS1.2 Node 1.2 Dikgatlhong Bigen Africa has been appointed as the Pumping Station Shashe river Letsibogo MMEWR representative. Pumping Station Link 1A2 Letsibogo dam PS1.1 Node 1.1 EMERGING ECONOMY Motloutse river Botswana Selebi-Phikwe BPT1A2 Link 1B2 C PS2.2 An emerging economy in the SADC re- Link 1A1 1 Moralane Pumping Station BPT1A1Moralane BPT Link 1B1 NSC-2A PS2.1 FT2A2 Link 2A2 Node 1A gion, Botswana is strongly reliant on its Node 2 2 Link 2A1 Dikalate BPT km 50 mining activities, especially of diamonds, BPT2A1 Node 2A which are focused in the eastern area Link 2B2 around the capital of Gaborone. Th is Link 2B1 Palapye NSC-2.1.1 wellfield km 100 Palapye Link 2B2 area is also the most populated region in C SR2B BPT2B Palapye Reservoirs W 3 PS3.2 Palapye WTW Lotsane river Link 2C2 Link 2B1 4 Node 2B the country. Increasing water utilisation Link 2C1 Limpopo river PS3.1 Lotsane river Palapye Pumping Station NSC-2.1.2 Node 3 here is being addressed by the North- Link 3A2 Link 3A1 FT3A2 South Carrier (NSC) water transfer Tewane BPT BPT3A1 km 150 Node 3A scheme, initiated by the Botswana gov- Link 3B2 Link 3B1 ernment, not only to meet a fundamental Mahalapye Reservoir Mahalapye 5 C and WTW W human need, but also as a key require- NSC-2.2 SR3B Node 3B Palla Road wellfield Mahalapye river km 200 Limpopo river ment for infrastructure development and Lephalala river Node 3C Link 3C2 economic growth. Link 3C1 Node 3D Palla Rd Injection Serome river Link 3D2 LinkMEP 3D1 emergency connection Serorome BPT BPT3E26 Link 3F2 Link 3E2 Mokolo river PS4.2 Mmamabula Energy Link 3E1 Serorome Pumping Station BPT3E1 Limpopo river 7 Link 3F1 Project THREE-PHASE WATER SUPPLY PLAN PS4.1 Bonwapitse river Node 3E FT4A2 Node 4 Link 4A2 km 250 Link 4A1 The implementation of the NSC up- 8 Node 4A grading works, a three-phase plan, Link 4B2 Khurutshe (Masama) Injection Link 4B1 Khurutshe Matlabas river (Masama) wellfield is being led by the MMEWR, with Ngotwane river Node 4B Link 4CA2 Link 4CA1 Limpopo river km 300 Civil Engineering November 2012 49 9 FT4BA2 South Africa Link 4CB2 Node 4BA 10 Crocodile river Bokaa dam Link 4CB1 Node 4C km 350 Bokaa Discharge NSC-2.3 The principal components and C Link 4D2 Metsemothlaba river Link 4D1 Mmamashia Reservoir W Mmamashia WTW Node 4D SR4D PS5.1 work packages of the NSC Mmamashia PS5.2 11 Marico river Pumping Node 5 Station Gaborone LEGEND Node 6 Power required C Operational control centre W PS6.1 Node 6A NSC 1 NSC 2 Water Treatment Works Refer to application for reference numbers Gaborone dam Gaborone Discharge responsibility for water resource Shashe Dams which feed on three tribu- In order to protect and control planning, control, legislation and taries of the Limpopo River in central access to the NSC, the MMEWR has regulation, while the Water Utility Botswana – the Motloutse, Shashe resolved to acquire and register rights Corporation is participating as op- and Tati Rivers. Construction of the to the NSC corridor from Dikgatlhong erator and key technical partner. Dikgatlhong Dam also commenced, Dam to Mmamashia. A single cor- Th e second phase of the NSC (NSC-2), along with its connection to the first- ridor, varying between 50 and 70 m in of which the planning stage commenced phase break pressure tank number 1. width, will be acquired to accommodate in 2007, is aimed at completing a water This dam is at present nearing comple- each of the three phases, the fibre- transfer strategy that feeds on various tion and should be substantially filled optic communication backbone and dams, existing or newly emerging from by the time the NSC is commissioned. the maintenance road. Environmental the fi rst phase (NSC-1, completed in Upgrading of various aspects of phase investigations have been undertaken 1999). Second-phase construction is one is still to be commissioned. for the primary corridor, and a manage- set to commence in the second quarter Pumping stations are located at ment entity is in place. Further investi- of 2012, with Bigen Africa acting Letsibogo, Moralane and Palapye (with gation and authorisations were pursued as the MMEWR representative. another envisaged for Seroroue) and on bedding and gravel-wearing course In the mid-1990s, the Botswana deliver from 1 175 ℓ/s to 2 300 ℓ/s, with materials along the route of the second government adopted a national water operational capacity of between 2 MW phase. Borrow pit leases and mining supply plan which identified the need and 3 MW respectively. Th e fi rst-phase licences are also a requirement. for the NSC to connect Letsibogo pipe varies in diameter from 1 400 ND In phase two, the direct water transfer Dam on the Motloutse River to the to 1 100 ND and was constructed from route will run primarily alongside north- Mmamashia water treatment works in a combination of materials, including south traffi c route A1 and pass the de- northern Gaborone, and to supply the GRP and steel. Further pipes will be mand nodes of Palapye, Mahalapye and Palapye and Mahalapye water treatment constructed from either steel or ductile Mmamabula, where raw water is treated, works. Mmamashia is also supplied iron, while consistency in other principal en route to Mmamashia in northern from the smaller Bokaa Dam, directly plant and material selections, including Gaborone. National electricity generation north of it. The first phase included the the key requirement of local maintain- occurs at Morupule within the Palapye importation of raw water into Gaborone ability, is required by the government. complex, and potential export generation from the Moletedi Dam in the North Communication and control signals can be established in the future on the West province of South Africa, and will mainly be by fi bre-optic cable with Mmamabula coal fi eld between Mahalapye the construction of the Letsibogo and backup by wireless radio data link. and Gaborone. Water reclamation from Ian Bettesworth, Executive Director of Bigen Africa, in the foreground, at the signing of the 1.5 billion pula NSC-2 EPC contract, together with offi cials from the MMEWR (client) and the CWJV (contractor) 50 November 2012 Civil Engineering the Gaborone water treatment works at mentation will be needed, most likely pre-treatment and secondary treatment Glen Valley is also planned to supplement from the Zambezi River in the Kasane works need to be added. At Gaborone, local water resources. area where the Botswana govern- treatment works for raw water and other Eutrophication of local Gaborone re- ment has a significant allocation for process upgrading must be undertaken, sources in the Bokaa and Gaborone Dams both primary use and agriculture. with construction of further secondary (and in future of the Dikgatlhong Dam) is It is anticipated that second-phase treatment works to follow. a technical matter that requires manage- construction will be completed within 24 Second-phase implementation fol- ment and design consideration. months, with commissioning and trial lows a three-stage bid procedure, namely As far as phase three is concerned, operation expected by mid-2014. pre-qualifi cation, pricing and EPC de- the MMEWR has initiated environmental sign, and bid development. Local content scoping and prefeasibility planning. An UPGRADING STILL IN THE PIPELINE is a key requirement of the Botswana overall NSC transfer decision support For purposes of eff ective management government to ensure a direct contri- system, factoring in current resource and redundancy, the three phases of the bution to the growth of the national storage levels, water quality, treatment NSC have been planned as separate, inde- economy. Th e preferred bidder for stage demands and pumping and treatment pendent delivery systems within a single 2.1 of the NSC is CWJV (WBHO and costs, will be established to determine corridor, but operating under an integrated CCC) and the professional service pro- water source and transfer requirements communication and control system. vider for Dikgatlhong Dam and NSC-2A from local resources, and via the three Upgrading work which still needs is the Bergstan, Gauff and Jeff ares & phases of the NSC. to be done includes the introduction of Green joint venture. For stage 2A of the The NSC is expected to deliver variable speed drives at some of the dams, NSC, the civil contractor is the China 45 Mm³ of water per annum and costs the construction of a new dam, and the State/Excavator Hire joint venture. were estimated, in 2010, to amount adjustment of the main transfer link be- to P5.5 billion. The summarised tween the Bokaa Dam, the Mmamashia INFO yield of the eastern Botswana dams water treatment works, the Gaborone Annette van Zyl is calculated at 95% assurance, and is water treatment works and the Gaborone Communications Manager expected to meet the demand until Dam. Th e Palapye water treatment works Bigen Africa Services (Pty) Ltd 2035 or so, after which further aug- need to be doubled and at Mmamashia, [email protected] Civil Engineering November 2012 51 www.sappma.co.za Southern African Plastic Pipe Manufacturers Association.