Name and Location
Ingula pumped-storage scheme project, on the border between the Free State and KwaZulu-Natal provinces, South Africa.

Client
Eskom.

Project Description
The Ingula pumped-storage scheme, located within the Little Drakensberg mountain range, 23 km north-east of Van Reenen’s Pass, will comprise an upper dam (Bedford) and a lower dam (Braamhoek). The upper reservoir site is located in the Free State and the lower reservoir site in KwaZulu-Natal. The escarpment forms the border between the two provinces.

The distance between the upper and lower reservoirs will be 4.6 km, with an elevation difference of about 470 m.

The reservoirs will be connected through underground waterways and the underground powerhouse complex, which will house four 333 MW pump turbines with a total capacity of 1 332 MW, a machine hall, a transformer hall and associated tunnels, shafts and caverns.

The twin headrace waterways, consisting of concrete and steel-lined headrace tunnels, pressure tunnels and shafts, will link the upper reservoir with the pump turbines. The draft tubes, concrete-lined surge shafts and a single concrete-lined tailrace tunnel will connect the pump turbines to the lower reservoir.

The upper reservoir is a concrete-faced rock-fill embankment dam, 41 m high, with a total capacity of 22.4-million cubic metres and an active water storage volume of 19.2-million cubic metres. The 39-m-high lower dam comprises roller-compacted concrete, with a total capacity of 26.3-million cubic metres and an active storage volume of 21.9-million cubic metres.

The scheme will be operated on a weekly cycle and will have an overall cycle efficiency of 78%.

Value
R25.9-billion. As at December 31, 2013, R18.8-billion had been spent.

Duration
The pumped storage scheme is planned to be fully operational in 2015.

Latest Developments
Eskom has reported in its New Build News for January 2014 that excavation and rock support works on the underground works have been completed and that civil works, together with the installation of the turbine units and other mechanical items, are under way. Civil works include the placement of about 500 000 m³ of concrete.

The civil works activity remains critical in terms of the overall project completion, owing to access requirements for the transformer and electrical packages. The intake and outlet structures have been completed.

Other major underground works activities under way, as at December 31, 2013, are:
• the construction of intake channel slabs and walls, intake structure with operations and maintenance building construction 43% complete.
• surge Shaft 3 and 4 post tensioning, which is 70% complete.
• inclined high-pressure shafts (IHPS) 1/2 and 3/4, with the low-pressure head race tunnel (LPHT) 1/2 concrete lining 85% complete and grouting activities in LPHT 3/4 45% complete.
• grouting at the high-pressure penstocks (HPPs) 2 and 4 are 100% complete, with at HPP 3 being 45% complete and HPP 1 being 25% complete.
• the tailrace tunnel, with steel fixing, is 98% complete, with concrete lining 97% complete and the grouting 29% complete.
• construction at surge chamber base 3/4 is 97% complete and surge chamber base 1/2 80% complete.
• the exploratory/cable access portal structure, with portal structure construction 95% complete.
• the machine hall (MH) Unit 3 concreting of floor slabs and generator floor is 100% complete and the operating floor is 10% complete.
• the MH Unit 4 concreting of the floor slabs and the generator floor is 100% complete.
• The concrete to first floor level west of the control room is 10% complete and the concrete of the intermediate level east is 45% complete.

Activities under way on the main underground works package, as at December 31, 2013, include:
• the continuation of the construction of intake structure operations and management building;
• the grouting of LPHT 3/4 and the concrete lining of LPHT 1/2;
• the concrete lining and grouting activities in the tailrace tunnel.
• the surge chamber base 3/4 top slab and the top slab of surge chamber base 1/2 will also be completed.

Key Contracts and Suppliers
The Braamhoek Consultants Joint Venture (BCJV), consisting of Gibb, Knight Piésold and SSI (civil, mechanical and electrical engineering, detailed design, tender documentation, design monitoring and construction supervision); Murray & Roberts (exploratory tunnel); Grinaker-LTA (access roads); CMI JV, comprising CMC di Ravenna, PG Mavundla and Impregilo (underground civil works); Afriscan (water supply, sewage treatment, small access roads and building temporary Eskom offices); B&E Quanza Group (aggregate quarry); Acer [Africa] (environmental consultants); Braamhoek Dam JV (BDJV), comprising Concor Roads & Earthworks, Wilson Bayley Holmes-Ovcon, Edwin Construction and Silver Rock (dam contract); Voith Siemens Fuji Hydro Power Generation (main generating plant); Deutsche Bank (R1-billion loan); Voith (mechanical auxiliary plant and turbines and generators) ABB (electrical balance of plant); NCC Environmental Services (independent environmental control officer services); Konecranes (heavy-duty cranes); Letacla (fibre-optic communications) and Siemens (generator transformers).

On budget and on time?
The first 333 MW unit was initially expected to be commissioned by January 2013; however, it will only be commissioned during the first quarter of 2015.

Contact Details for Project Information
Eskom executive project manager Carel Stoop, email StoopCJ@eskom.co.za
Ingula Visitors Centre, tel +27 36 342 3122 or email fifi.meyer@eskom.co.za.
ABB, tel +41 43 317 6480 or fax +41 43 317 6482.
Gibb, tel +27 11 519 4600 or fax +27 11 807 5670.
BDJV (Concor Roads & Earthworks), tel +27 11 495 2222.
CMI Mavundla JV, tel +27 36 638 6000.
Eskom media desk, tel +27 11 800 3304/3309/3343/3378, fax +27 11 800 3805 or email mediadesk@eskom.co.za.
Impregilo, tel +39 02 4442 2115.
Voith Siemens Hydro Power Generation, tel +49 7321 370 or fax +49 7321 37 6180.
NCC, tel +27 21 702 2884, fax +27 86 555 0693 or email info@ncc-group.co.za.
Konecranes, tel +27 11 864 2800.