Malaysia’s Water Tunnel Project-
Malaysia’s capital city Kuala Lumpur and its surrounding areas of Selangor and Putrajaya have experienced rapid economic growth since the 1980s. This growth has been accompanied by a significant increase in water requirements for residential, commercial, and industrial purposes. In 2013, water consumption in the state of Selangor was recorded at 2,989 million litres per day (mld), which was the highest in the country. Further, latest available estimates (April 2014) show that the 6.7 million consumers in the Kuala Lumpur, Selangor, and Putrajaya regions require about 4,351 mld of water. Against this, the total production capacity of the 34 water treatment plants (WTPs) that serve the region is 4,686 mld. However, these WTPs are mainly reliant on the rainfed Selangor dam for sourcing water and hence, do not offer a sustainable and secure water supply. This was clearly demonstrated with the onset of a drinking water crisis in Malaysia due to the dry spells brought on by the El Nino phenomenon in February 2014.
To address these concerns, the Ministry of Energy, Green Technology and Water, which is responsible for formulating water supply and sanitation policies at the central level and undertaking high-impact projects, is implementing the Transfer of Raw Water from Pahang to Selangor scheme. The RM 3.9 billion scheme intends to fulfil the water requirements of the citizens in Selangor and adjoining areas until 2025. It involves channelling raw water from the sparsely populated rural areas in Pahang state to the more populous urban areas in Selangor state and the federal territories of Kuala Lumpur and Putrajaya. Broadly, the scheme comprises two components – the Raw Water Transfer project from Pahang to Selangor and the Langat 2 Water Treatment Plant and Distribution System Project.
The first component – the Raw Water Transfer project from Pahang to Selangor – comprises five subcomponents. These include construction of the 35 metre high Kelau dam, the 24 km long Kelau river and the Semantan river catchment areas, and an intake and pump house at the Semantan river. It also includes laying of twin raw water pumping mains of 3 metre diameter over a length of 11.8 km. The final subcomponent is the construction of a 44.6 km long tunnel with a diameter of 5.2 metres. This tunnel will convey raw water from the Semantan river in Pahang to the Langat river in Selangor.
On the other hand, the second component comprises construction of a 1,130 mld capacity WTP, two balance tanks, and five storage tanks with capacities ranging from 23 to 80 million litres. It also includes laying a 68 km long pipeline distribution network.
Project details
Work on the Pahang Selangor Raw Water Transfer Tunnel (PSRWT) Project began in June 2009. It is designed to provide 1,890 mld of water to residents in Selangor and adjoining areas. Under the project, raw water will be pumped from the Semantan river in Pahang and transferred to the proposed Langat 2 WTP in Selangor. The water will be conveyed through the twin raw water pumping mains and the water transfer tunnel. Water will flow through the tunnel by gravity at a gradient of 1:1900 and at 75 per cent to 80 per cent full flow. In addition, the 299 million cubic metre capacity Kelau regulating dam will ensure that there is adequate water in the Semantan river during the low flow period.
Currently, the PSRWT is the longest tunnel in the Southeast Asian region and the sixth longest tunnel in the world. Another distinguishing feature of this subcomponent is its large overburden, which is the distance of the tunnel from the surface of the earth. It has a maximum overburden of 1,246 metres and about 5 km of the tunnel section has an overburden of more than 1,000 metres.
In 2009, the Ministry of Energy, Green Technology and Water contracted the project to a consortium of Japanese companies Shimizu Corporation and Nishimatsu Construction, in a joint venture with Malaysian companies IJM Corporation and UEM Builders. The duration of the contract was 1,825 days, from June 1, 2009 to May 30, 2014. In addition, Australia-based consulting engineering company SMEC has provided construction supervision and consultancy services for the project while Sweden-based GIA Industries has provided people transportation and air ventilation solutions. Further, the structural steel works, piling works, and ground support and stabilisation works were contracted to Singapore-based Kori Holdings.
To facilitate construction, the tunnel has been divided into three parts, of 11.77 km, 11.8 km, and 11.3 km length. About 50 per cent of the tunnel length lies in Pahang. The inlet of the tunnel is located at Karak town while the outlet is located at Langat headwaters. Construction activity on the tunnel began in 2010 and the final excavation work was completed in May 2014. The tunnel has a design discharge of 27.6 cubic metres of raw water per second. In order to excavate swiftly in difficult high cover rock conditions, the ministry had developed a programme of combining multiple tunnel boring machine drives with the new Austrian tunnelling method at the inlet and outlet portals. Over a length of 35 km, excavation has been carried out using tunnel boring machines, while the remaining length has been excavated by conventional drilling-and-blasting or by cut-and-cover methods.
The big-ticket project is the largest ongoing infrastructure project in Malaysia and is being financed through a long-term soft loan from the Japan Bank for International Cooperation. In March 2005, an agreement was signed between the Japanese and Malaysian governments for a JPY 82.04 billion loan for the PSRWT Project. The loan has a repayment period of 40 years with a grace period of 10 years. The interest rate on the loan is 0.95 per cent. The loan amount has been utilised for construction of the water transfer tunnel and the dam, related works, and for consulting services, which include detailed design and implementation supervision.
Future outlook
As of May 2014, the PSRWT Project was 96 per cent complete and was scheduled to be fully completed by December 2014. The ministry also had plans to conduct trial runs on the project in early August 2014 to channel about 500 mld of water into the Langat river. However, the project could not meet its original deadline and has faced significant delays since then. The major reason behind this is reported to be the delay in the construction of the Langat 2 WTP. The construction of the Langat 2 WTP was initially scheduled to begin in 2010 but had been held up due to political reasons. In April 2014, the project has gathered pace with the award of a construction contract. It is now scheduled to be completed by April 2017. Consequently, the PSRWT Project is also expected to be commissioned in 2017. This will address the drinking water requirements of the fastest developing regions of the country. According to ministry estimates, it will also generate revenue of RM 70 million per year for Pahang. Both these factors are expected to act as a further impetus to economic growth in Malaysia.
