Our Water Sources

Highland forests are usually high-rainfall areas. Precipitation or rain is formed in the highlands resulting from the condensation of moisture in the atmosphere. Scientific evidence shows that forests at elevations above 1,500m also have the ability to strip moisture from the wind-blown dusts. This function is important especially during low rainfall periods.

Forests in the highlands have been likened to a giant sponge that absorbs and accumulates rainwater intercepted by vegetation and the forest floor. Highland forests release water continuously into streams and rivers that flow downstream to coastal areas where they merge with the sea. The sun’s energy causes water from the sea and other water bodies to evaporate into water vapour that forms clouds. This repeated process of water dispersal, absorption and evaporation is known as the ‘water cycle’.

The highland forests are often referred to as natural ‘water towers’. This is because most rivers originate from there and a significant amount of water from rainfall is captured and accumulated by these forests. In fact, a large proportion of the river volume originates in the highlands.

Among the eight prominent mountain ranges forming Peninsular Malaysia’s highland landscapes, the Main Range is the longest and most contiguous. It stretches some 500km across five states - Kelantan, Perak, Pahang, Selangor and Negeri Sembilan. The Main Range is the peninsula’s most important catchment area, since many of the major rivers supplying freshwater in these five states originate from its forest base.

In the East Malaysian states of Sabah and Sarawak, there are at least 18 mountain ranges and isolated mountain areas, all of which perform important roles in providing sources of freshwater supply.

1.    Rivers and Agriculture
In Malaysia, rivers support agricultural development and productivity. The highest percentage of water demand in Malaysia is for irrigation in the agriculture sector. Irrigation is employed primarily to cater for the double cropping of paddy.

2.    Rivers for Domestic and Industrial Water Supply
In Malaysia, more than 90% of our water supply comes from rivers and streams. The demands for residential and industrial water supply has grown rapidly following the country’s economic shift towards industrialization in the 1980s, coupled with an increase in population and urban growth.

3.    Rivers as Sanctuary for Biodiversity
Malaysian rivers are endowed with rich plant and animal life. Our rivers support and sustain biodiversity within the river itself, along riverbanks and in the surrounding environment. As a river journeys from its highland origins on to its lower reaches, plants and animals, especially aquatic life, differ along its seaward course.

4.    Rivers for Provision of Food Sources
Traditionally, the importance of freshwater fisheries relates more significantly to the livelihood of rural riverine populations. In recent years, however, recreational or sports fishing has expanded rapidly, adding a new economic dimension to the freshwater fisheries resource. Besides the popular edible fish species like Lampam Sungai (Puntius schwanenfeldii) and Jelawat (Leptobarbus hoeveni), freshwater prawns and certain aquatic plants are also major food sources derived from rivers.

5.    Rivers for Transportation
Some of the remote and interior villages in Sarawak, Sabah, Perak and Pahang depend on rivers for transportation. This traditional role of rivers continues today but at a much smaller scale than before. Without alternative modes of transportation and limited access, rivers provide the sole means to get in touch with the outside world.

6.    Rivers for Generating Hydropower
For the period from 1996 to 2000, hydroelectric power output constituted between 7% -12% of the total national energy generated annually. It was estimated that 85% of the total hydropower potential of the country is found in the states of Sabah and Sarawak.

7.    Rivers for Recreation
Many Malaysian rivers have high recreation value, which provide many opportunities for outdoor activities. For the adventurous, the Pelagus rapids on Rajang River in Sarawak and the Padas, Tuaran and Papar Rivers in Sabah are popular for white-water rafting, while the Nenggiri River in Kelantan and Tembeling River in Pahang are favourite locations for kayaking and canoeing.

There are a number of relatively accessible scenic rivers in Malaysia for those who prefer nature and wilderness experiences. Among them are the Endau River in Johor, the Tembeling River in Pahang, the Skrang River in Sarawak and the Menanggol River in Sabah. Rivers such as the Tembeling and Nenggiri are also well-known historic routes, making them ideal for educational recreation. For those seeking relaxation and fun retreats, there are many beautiful waterfalls throughout the country that have become popular spots for such use. Recreational or sports fishing is also becoming popular with many anglers hiking to the upper reaches of rivers to fish.

Note:
The Department of Environment (DoE) started monitoring river water quality in Malaysia in 1978. As of 2003, there were 926 manual stations located in 120 river basins. In addition to the manual stations, 15 automatic water quality stations have been installed at major rivers to capture real time data on specific parameters to monitor river water quality changes continuously.