Ingenieur July-Sept 2016 Ingenieur July-Sept 2016 | Page 21

Figure 5: Current hydropower development in Sarawak Figure 7: An aerial view of Murum River near the project site prior to construction Figure 6: Murum HEP Reservoir The Murum HEP is the second largest in Sarawak (after Bakun). It is the first large-scale sustainable energy project developed by Sarawak Energy Berhad on behalf of the State Government as part of the Sarawak Corridor of Renewable Energy (SCORE) development. SCORE is a major development initiative designed to elevate Sarawak to developed state status by harnessing the state’s abundant hydropower resources to attract energy-intensive industries into designated areas such as Samalaju, by providing competitively priced, renewable and reliable energy, resulting in business and industrial growth, and raising incomes and living standards overall. MURUM CATCHMENT AND RESERVOIR The Murum river catchment comprises the uppermost sub-basin of the Rajang River in central eastern Sarawak, adjacent to the border with Kalimantan, Indonesia. The catchment has an area of 2,750 km2 at the Murum dam site, and comprises mountainous terrain characterised by ridges of sandstone, shale and mudstone outcrops. Ground elevation varies from 420m at the dam site to over 2000m at the border with Kalimantan. Soils are shallow but support a cover of a dense rainforest, parts of which are in the process of being selectively logged. The catchment is drained by two major tributaries of the Murum, namely the Danum and Plieran rivers (see Figure 6), about 37 km downstream of the dam site, the Murum joins the Balui River just before it enters the gorge of the old Bakun rapids and now the Bakun reservoir. The reservoir lies between the foundation elevation of 400masl at the dam site and maximum operating level of elevation 540masl giving a depth of 140m. The total storage volume at the maximum operating level (540masl) is 19