A catchment is an area where water is collected by the natural landscape. Healthy catchments help to protect our rivers, dams and groundwater environments and provides our community with:
- • Clean drinking water
- • Natural areas for recreation
- • Habitat for plants and animals
- • Healthy vegetation and waterways
- • Reliable and clean water for stock and irrigation
- • Opportunities for sustainable agriculture and industry
According to Prof Dr Chan Ngai Weng, Universiti Sains Malaysia logging will expose the land. Rain splash erosion and surface erosion will wash sediments into the rivers, causing water pollution and the shallowing of river beds. Logging activities in water catchment areas likes Ulu Muda Forest in Sik, Merapoh Forest in Kuala Lipis and Bukit Ulu Sat, Bukit Tapong in Pasir Puteh has polluted the river and threatened the water supply as well as wildlife species.
Uncontrolled logging could hurt the efficacy of water catchments and jeopardise the economies of affected areas. As for example, the Muda Dam water catchment area at the Ulu Muda Forest Reserve is pumped to the Pedu Dam and it is primarily used for the Muda irrigation scheme of about 97,000ha of padi. Uncontrolled logging has caused the massive landslides as for instance, on 2015 massive landslides occurred at KM52.4 of the Karak Highway, near Lentang-Bukit Tinggi was due to uncontrolled logging in water catchment area. Besides, the destruction of watershed areas will result in more flash flood and massive flood. Deforestation plays many roles in the flooding equation because trees prevent sediment runoffs and hold more water. The release of sediment due to deforestation has a bigger impact on floods. On 2014, the
East Coast of Malaysia has been struck with the worst flood in history during the northeast monsoon due to uncontrolled logging. The uncontrolled logging in water catchment area also has affected the water quality due to the deposition of sediment. The water becomes murky and muddy. Some people still fully relies on the natural highland water source for their daily use. For example, Orang Asli villagers in Gua Musang uses natural water source for cooking, bathing and other potable uses. However, due to uncontrolled clearing of the forest, the water catchment areas in Lojing Highlands have destroyed.
Apart from resulting more flash floods and landslides, logging also affect the water temperature. Logging removes large trees that normally provide shelter and thermal cover which then raises water temperatures and pH, and degrades the chemical and ecological conditions and food webs that fish need to survive. Besides that, the uncontrolled logging could alter the local microclimate, resulting in hotter and drier conditions which contribute to global warming and can hasten rapid climate change.
Uncontrolled logging in water catchment area should be taken seriously as the water catchment area in Kedah has shrunk by 87.3% – from 98,400ha in 1969 to just 12,484ha in 2017. Apart from that, more and more illegal and uncontrolled logging activities have occurred in other parts of water catchment in Malaysia such as Ulu Tembeling and Lojing.
Safe and high quality drinking water begins with the safe and healthy drinking water catchments. Thus, effective action must be taken seriously and immediately. Uncontrolled logging must be stopped so that consumers could have safe drinking water from safe water supply.
Nur Imani binti Abdullah
Forum Air Malaysia