The Ingenieur Vol. 65 Water Power | Page 9

COVER FEATURE MANAGING CHALLENGES IN THE MENGKUANG DAM EXPANSION PROJECT By Ir. Khor Chai Huat and Ir. Lai Kim Fui, Angkasa Consulting Services Sdn Bhd Tuan Hj. Ir. Noor Azahari Zainal Abidin, Jabatan Bekalan Air, KeTTHA The Mengkuang Dam Expansion Project – Construction of the Dam and Associated Works Stage 1 – completed in July 2015 in Penang, features a 45m high and 2km long embankment dam and raising the height of the existing 1km long embankment by 11m. The challenges in managing risks associated with construction of a new dam adjacent the existing dam, impact of existing quarry operation, shortage of construction materials and other major issues required effective solutions. T he construction and associated works (contract value of RM 607million) under the E xpansion of Mengkuang Dam Project is a large scale project. The project will increase the reservoir’s active storage from 22 to 73.5 million m3 and increased the raw water supply capacity from 350 to 650 million litre per day. This water source development project is vital for the economic development of Penang State. The project is located in District of Seberang Perai Figure 1: Location Plan Tengah, Pulau Pinang and about 40km east of Butterworth and approximately 8km from Bukit Mertajam. The existing Mengkuang Dam which forms part of the Mengkuang Pumped Storage Scheme was commissioned in 1985. The existing earthfill dam is about 1 km long and 31m high (see Figure 2). The existing dam crest will be raised by 11m in height. A new dam 2km in length and about 45 m high will be constructed at the left valley. The new dam under the Stage 1 works was a zoned earthfill dam as illustrated in Figure 3. Figure 4 shows the new dam completed on 31st July 2015. The draw- off tower located near the left abutment of the dam and valve house downstream of the draw-off tunnel is shown in Figures 5 and 6 respectively. 7