Acting as natural water reservoirs, they help ensure that this water is clean and free from silt and sediment. These forests are important water catchment areas. It is the source of many important rivers that supply fresh water to the states of Kelantan, Perak, Pahang, Selangor and Negeri Sembilan. And it is up to us to preserve the quality of our water sources for the sake of our own health and well-being. The tremendous economic value of clean water will quickly become evident if we need to pay the high costs of cleaning a polluted water supply.
Landslides can devastate roads, posing great danger to passing vehicles.
The slopes of highland forests also act to prevent landslides . Highland forests slow down the flow of rainwater down slopes and help retain some of this water. Rivers become choked with silt and water quality everywhere suffers. The catastrophic consequences of landslides can cause devastation for people and the environment. Examples include the June 1995 landslide in a Genting Highlands slip road, which resulted in at least 21 deaths and 22 injuries, and the January 1996 landslide at Gua Tempurung.