The Study Area of the Sg. Similajau NAWABS covers a total area of approximately 652 sq. km and is located in the state of Sarawak, within the administrative boundary of the division of Bintulu. Bintulu Division covers a total land area of approximately 12,166 sq. km and comprises two administrative districts, namely the Bintulu District (7,220 sq. km) where the Sg. Similajau Basin is located and the Tatau District (4,946 sq. km).
The Study Area also covers parts of the Samalaju Industrial Park (SIP), the Similajau National Park and the Bukit Tiban National Park. The SIP is one of the five key development nodes launched in Sarawak under the Sarawak Corridor of Renewable Energy (SCORE) initiative in February 2008. Aluminium smelting, chemical processing and industrial gases are some of the prime industries which are currently operational in the SIP.
The Similajau National Park is one of the dedicated conservational areas of Sarawak located about 30 km northeast of Bintulu and is well known for its rich diversity of flora and fauna and the presence of pristine white sandy beaches. 73% of the Similajau National Park (6,583 ha out of 8,996 ha) lies within the Study Area. For the Bukit Tiban National Park, 2,705 ha of its 8,000 ha gazetted area is located within the Study Area.
Sg. Similajau originates from the highlands located at the southern part of the Study Area and has a total length of about 70 km. The Sg. Similajau Basin covers a total area of about 534 sq. km, and prior to discharging into the South China Sea, Sg. Similajau is joined by a number of tributary rivers such as Sg. Siod and Sg. Sigrok. The Study Area is divided into 16 subcatchments. Out of these, 11 subcatchments form the Sg. Similajau Basin while 5 are sub-basins for small rivers directly discharge into the sea. The small rivers are Sg. Kabalak, Sg. Niab ruck, Sg. Sebubong, Sg. Suroba and Sg. Siat.
The Study Area experiences wet season from October to January. Within the Sg. Similajau Basin, the average rainfall is 3,232 mm/year. The river basin receives average net runoff of 1,082 MCM (2,026 mm/year), of which 14.3 MCM (1.3%) is utilised for potable and non-potable use (11.3 MCM and 2.9 MCM respectively), 108.2 MCM (10%) for environmental flow and 959.8 MCM (88.7%) of the unused runoff is discharged into the sea.
There is only one government operated water treatment plant (WTP) in the Study Area, namely the Samalaju WTP which is supplying water to the SIP and Kampung Nyalau. The Samalaju WTP sourced its raw water from the Sg. Similajau Intake as well as treated water from the Nyabau WTP which obtained its raw water from Sg. Sibiu and Assyakirin Dam located near the Bintulu Town. There is also future planning to transfer water from Btg. Kemena as the water demand of the Study Area will increase in the future in line with the industrial development at the SIP.
Of the potable water demand supplied by the Samalaju WTP to the SIP and Kampung Nyalau, 92.2% is used by the industrial sector, 6.1% by commercial sector and 1.7% domestic use. Under the most conservative scenario, the water demand of the Study Area in year 2050 is projected to be 333.9 MLD (121.9 MCM).
Apart from the Samalaju WTP raw water abstraction at the Sg. Similajau Intake, oil palm plantation (OPP) which covers about 65% of the Study Area is also abstracting raw water via the OPP WTPs in the Study Area for domestic purposes as well as for palm oil mills usage. The potable water demand of the estates is fulfilled by six small-scale water treatment plants operated by the OPP owner. 88% (9.9 MCM) of the total raw water abstraction (11.3 MCM) is abstracted by the Sg. Similajau Intake while the OPP WTPs account for 12% (1.4 MCM) cumulatively.
The Study Area also covers parts of the Samalaju Industrial Park (SIP), the Similajau National Park and the Bukit Tiban National Park. The SIP is one of the five key development nodes launched in Sarawak under the Sarawak Corridor of Renewable Energy (SCORE) initiative in February 2008. Aluminium smelting, chemical processing and industrial gases are some of the prime industries which are currently operational in the SIP.
The Similajau National Park is one of the dedicated conservational areas of Sarawak located about 30 km northeast of Bintulu and is well known for its rich diversity of flora and fauna and the presence of pristine white sandy beaches. 73% of the Similajau National Park (6,583 ha out of 8,996 ha) lies within the Study Area. For the Bukit Tiban National Park, 2,705 ha of its 8,000 ha gazetted area is located within the Study Area.
Sg. Similajau originates from the highlands located at the southern part of the Study Area and has a total length of about 70 km. The Sg. Similajau Basin covers a total area of about 534 sq. km, and prior to discharging into the South China Sea, Sg. Similajau is joined by a number of tributary rivers such as Sg. Siod and Sg. Sigrok. The Study Area is divided into 16 subcatchments. Out of these, 11 subcatchments form the Sg. Similajau Basin while 5 are sub-basins for small rivers directly discharge into the sea. The small rivers are Sg. Kabalak, Sg. Niab ruck, Sg. Sebubong, Sg. Suroba and Sg. Siat.
The Study Area experiences wet season from October to January. Within the Sg. Similajau Basin, the average rainfall is 3,232 mm/year. The river basin receives average net runoff of 1,082 MCM (2,026 mm/year), of which 14.3 MCM (1.3%) is utilised for potable and non-potable use (11.3 MCM and 2.9 MCM respectively), 108.2 MCM (10%) for environmental flow and 959.8 MCM (88.7%) of the unused runoff is discharged into the sea.
There is only one government operated water treatment plant (WTP) in the Study Area, namely the Samalaju WTP which is supplying water to the SIP and Kampung Nyalau. The Samalaju WTP sourced its raw water from the Sg. Similajau Intake as well as treated water from the Nyabau WTP which obtained its raw water from Sg. Sibiu and Assyakirin Dam located near the Bintulu Town. There is also future planning to transfer water from Btg. Kemena as the water demand of the Study Area will increase in the future in line with the industrial development at the SIP.
Of the potable water demand supplied by the Samalaju WTP to the SIP and Kampung Nyalau, 92.2% is used by the industrial sector, 6.1% by commercial sector and 1.7% domestic use. Under the most conservative scenario, the water demand of the Study Area in year 2050 is projected to be 333.9 MLD (121.9 MCM).
Apart from the Samalaju WTP raw water abstraction at the Sg. Similajau Intake, oil palm plantation (OPP) which covers about 65% of the Study Area is also abstracting raw water via the OPP WTPs in the Study Area for domestic purposes as well as for palm oil mills usage. The potable water demand of the estates is fulfilled by six small-scale water treatment plants operated by the OPP owner. 88% (9.9 MCM) of the total raw water abstraction (11.3 MCM) is abstracted by the Sg. Similajau Intake while the OPP WTPs account for 12% (1.4 MCM) cumulatively.
Show More
