Water profile of Malaysia
The water profile of Malaysia is dominated by a supply regime of copiously flowing rivers and a widespread series of dams for surface water storage. Demand includes the growing human population, industry and agriculture, of which rice farming is the most water intensive crop. Water pollution from sanitary domestic sewage sources as well as industry are major challenges for the country, with the recent and ongoing growth of the population and the country's industrial base.
Malaysia is situated in Southeast Asia. It consists of two regions: peninsular Malaysia in the west lying between Thailand and Singapore, and the states of Sabah and Sarawak located in the east on the island of Borneo. The two regions are separated by the South China Sea. The total land area of the country is 328,550 square kilometers (km2). Malaysia is a federal country, divided into 13 states plus the federal territories of Kuala Lumpur and Labuan Island.
In peninsular Malaysia, a mountainous spine known as Banjaran Titiwangsa separates the east of the peninsula from the west. About 61 percent of the peninsula is below 100 meters (m) above sea level and the land is generally suitable for cultivation. The interior of Sabah is criss-crossed by a series of mountain ranges and hills, the most prominent of which is the Crocker range with the highest point at Gunung Kinabalu (4101 m). Sarawak is generally mountainous with the highest range forming the border with Indonesia.
In 1996, the total cultivable area was 14.17 million hectares (ha), or 43 percent of the total land area. About 5,095,818 ha, or 36 percent of the cultivable area, were cultivated. Permanent crops represented 91 percent of this cultivated area, while the remaining nine percent (445,700 ha) was under annual crops, mainly paddy. The agriculture sector is divided into large-scale plantations concentrating on three crops (rubber, oil palm, and cocoa), and smallholders who constitute the majority of the farming population.
In 1996, the population of Malaysia was estimated at 20.58 million inhabitants (45.5 percent rural). The population is concentrated along the west coast of peninsular Malaysia and in the capital city, Kuala Lumpur. The average population density in Malaysia is 63 inhabitants/km2. The Malaysian population grew at an average annual rate of 2.8 percent in the 1980s, but the rate has since slowed to the current 2.3 percent.
The total active population is estimated at 8,321,000 inhabitants, of whom 22 percent are engaged in agriculture. The contribution of agriculture to the Gross Domestic Product (GDP) declined from 18.7 percent in 1990 to 13.6 percent in 1995. In the same year, the agriculture sector contributed 19.1 percent of export earnings. Palm oil, rubber, and saw logs account for more than 58 percent of total agricultural exports.
Climate and Water Resources
Malaysia lies entirely in the equatorial zone. The climate is governed by the regime of the northeast and southwest monsoons. The northeast monsoon blows from October to March, and is responsible for the heavy rains which hit the east coast of the peninsula and frequently cause widespread floods. It also causes the wettest season in Sabah and Sarawak. The southwest monsoon period occurs between May and September, and is a drier period for the whole country. The period between these two monsoons is marked by heavy rainfall.
The average temperature throughout the year is very stable (26°C), and the mean annual rainfall is 3,000 millimeters (mm). Regional variations in temperature and rainfall are mainly due to topographic relief, e.g. the Cameron Highlands have a mean temperature of 18°C and an annual rainfall of over 2500 mm, compared to Kuala Lumpur's 27°C and 2,400 mm. In general, Sabah and Sarawak experience more rainfall (3,000-4,000 mm) than the peninsula. The humidity is high (80 percent) due to the high evaporation rate.
River Basins and Water Resources
Peninsular Malaysia is drained by a dense network of rivers and streams (there are about 150 major river basins), the longest being the Pahang River which follows a course of 434 km before reaching the South China Sea. It drains a catchment area of 29,000 km2. Other major rivers that also drain into the South China Sea are the Kelantan, Terengganu, Dungun, Endau, and Sedili rivers. Major river basins in the east of Malaysia tend to be larger than those in peninsula Malaysia. Malaysia's longest river is the Rajang River (563 kilometers) in Sarawak.
Out of an annual rainfall volume of 990 cubic kilometers (km3), 360 km3 (36 percent) are lost to evapotranspiration. The total surface runoff is 566 km3, and about 64 km3 (7 percent of the total annual rainfall) contribute to groundwater recharge. However, about 80 percent of the groundwater flow returns to the rivers and is therefore not considered an additional resource. The total internal water resources of Malaysia are estimated at 580 km3/year.
Major floods occurred in 1967, 1971, 1973 and 1983. Some 29,000 km2 are considered as flood-prone areas, affecting about 2.7 million people. The average annual economic damage caused by floods was estimated at US$40 million in 1980.
Lakes and Dams
On the west coast of peninsular Malaysia, the low gradient has resulted in large extensions of tidal flats and swamps. One of the swamp lakes is Lake Tasek Bera in Pahang State, with an area of 61.5 km2.
Malaysia has a total of 56 dams, of which 32 are more than 15 m high. The gross theoretical hydropower potential of peninsular Malaysia is 123,000 gigawatt hours per year (GWh/year), and that of Sabah and Sarawak together is 107,000 GWh/year. In 1995, the total hydropower generation was about 5,800 GWh, or 30 percent of all power production in Malaysia.
The annual internal renewable water resources are estimated at 630 km3. As surface water is readily available throughout the year, it is abstracted mainly for irrigation and domestic uses. The groundwater potential is limited to some pockets of the coastal region and is generally exploited by rural people to supplement their piped water supply. Surface water represents 97 percent of the total water use, while groundwater represents three percent (Figure 1). About 60-65 percent of groundwater utilization is for domestic and/or municipal purposes, five percent for irrigation and 30-35 percent for industry (Figure 2).
In 1995, the total production of drinking water from treatment plants was 3.95 km3, while the quantity supplied to domestic and industrial sectors was only 2.98 km3 (Figure 3). About 32 percent of the water produced is lost in the distribution system due to several factors such as pipe leakage, under-metering, and other unaccounted water losses.
Water supply is undertaken by government agencies and privatized water companies. The coverage for water supply is 99 percent for urban areas and 77 percent in the rural areas.
The total water demand increased from 8.7 km3 in 1980 to 12.7 km3 in 1995, and is projected to increase to 15.2 km3 by 2000. Irrigation currently accounts for about 9.7 km3 or about 76 percent of the total water consumption. However, irrigation demand is expected to taper off as no further expansion in irrigated paddy cultivation is envisaged.
Irrigation and Drainage Development
In Malaysia, the potential irrigable area accounts for about 413,700 ha. Irrigation development dates back to the end of the eighteenth century. The Kerian irrigation schemes were the first large schemes to be constructed, in 1892. Since the formation of the Department of Irrigation and Drainage in 1932, irrigated areas for paddy cultivation have progressively increased. By 1960, about 200,000 ha had been developed, the emphasis then being on supplementing rainfall for single crop cultivation.
During the 1960s and early 1970s, the introduction of double cropping of rice cultivation required the development of adequate water resources for the second cropping season. During the 1980s, the priority for irrigation took on a new dimension with the need to rationalize rice cultivation and increase its productivity (Figure 4). The Government developed a policy to concentrate efforts in irrigation development in eight large irrigated areas, designated as granary areas of the country and totalling 210,500 ha. They are the irrigated areas of Kada, Seberang Muda Perai, Trans Perak, Northwest Selangor, Kerian-Sungai Manik, Besut, and Kemasin-Semarak.
Malaysia has over 932 irrigation schemes covering an area of 340,633 ha, comprising 8 granary schemes (210,500 ha), 74 mini-granary schemes (29,500 ha), and 850 non-granary schemes (100,633 ha) (Figure 5). The non-granary schemes are scattered all over the country and their size varies between 50 and 200 ha. In addition, there are 21,967 ha which are inundation and control drainage schemes (1994 estimates). The total irrigation areas was estimated at 362,600 ha in 1994.
Irrigation is predominately for paddy cultivation and to a minor extent for vegetables and cash crops. Paddy cultivation is mostly carried out by individual farmers working on small plots of about 1-1.5 ha. Irrigation facilities for double cropping are mainly focused on the eight main granary schemes and the 74 mini-granary schemes, with an average cropping intensity of 150 percent. The current irrigation efficiency is around 35-45 percent with a water productivity index for rice of about 0.2 kilograms per cubic meter (kg/m3). The average yield for irrigated rice was 4 tons per hectare (t/ha) in 1995.
In the major irrigation schemes, flooding irrigation is practised on paddy fields, and the water depth is controlled individually by the farmers. Major irrigation schemes are designed with proper farm roads to cater for farm mechanization especially for plowing and harvesting. Most of the irrigation schemes are provided with separate drainage facilities. The issues of salinity, waterlogging, and water-borne diseases are not reported as being significant.
Farmers pay nominal irrigation charges which vary from US$3 to $15/ha/year. It is estimated that fees collected from farmers cover only 10-12 percent of the actual operational cost. The Government does not seek full cost recovery because the farming community is considered a low income group. A total of US$917 million have been spent on irrigation development by the Government since 1970.
The long-term objectives of irrigation development are:
- to provide infrastructure for 74 secondary granary areas in order to raise the cropping intensity from 120 to 170 percent by 2010;
- to provide infrastructure for the main granary areas in order to raise the cropping intensity from 160 to 180 percent by 2010;
- to convert 120 small paddy schemes to other crops by 2010;
- to develop 20 small reservoirs, 100 groundwater tube-wells, and 4 dams by 2010 in order to provide reliable irrigation by introducing new technologies and modern management to increase crop production.
In 1994, the total drained areas was 940,633 ha. About 600,000 ha were drained for oil palm cultivation, using public funding for smallholders.
The responsibility for water resources planning and development is shared by various government agencies. Malaysia has no single water resources authority for an overall coordinated planning and integrated river management approach.
The Department of Irrigation and Drainage (DID), under the Ministry of Agriculture, is responsible for the planning, implementing and operation of irrigation, drainage, and flood control projects throughout the country.
The Department of Agriculture (DOA) is responsible for providing advice and extension services to the farmers.
In the water supply sector, the Public Works Department (PWD), under the Ministry of Public Works, is responsible for the planning, implementation and operation of urban water supply projects. However, in line with the Government's privatization policy, many water supply projects have already been taken over by water supply companies or privatized.
The Ministry of Health (MOH) provides untreated but drinkable water to rural communities not served by the local water authorities. The MOH also monitors water quality at water treatment plant intakes as well as the quality of water within the distribution system for compliance with national drinking water standards.
The control of water pollution is the responsibility of the Department of Environment (DOE), which is empowered to enforce compliance with effluent standards for point sources of pollution. The Ministry of Housing and Local Government is responsible for compliance with regulations and standards on sewerage works which have been privatized to a national sewerage company.
Although either directly or indirectly much legislation touches on water resources, most of the existing laws are considered outdated. The Water Act of 1920 is inadequate for dealing with the current complex issues related to water abstraction, pollution, and river basin management.
Trends in Water Resources Management
Agriculture will remain the main user of water in the future. However, its importance will decline from the present 76 percent to about 70 percent of total water consumption by 2000. In the irrigation sector, future efforts will focus on demand management through improved water management rather than on supply management.
Future trends in paddy cultivation will focus on group farming as practiced in the Trans Perak Area Integrated Agriculture Development Scheme. In the long term, sustainable paddy cultivation will depend on the setting up of effective farmers' organizations. A more business-oriented paddy farming is seen as a way to reduce government subsidies to small farmers. Owing to the high cost of paddy production, the National Agriculture Policy (1992-2010) aims to reduce gradually the country's self-sufficiency in rice from the current 80 to 65 percent.
In the water resources sector, there is a need to review the planning and development of dams. Most of the existing dams were generally designed for one single purpose by various government agencies and privatized utility companies. Future dams will be designed with consideration for multipurpose usage through improved coordination and the optimization of resources. There is also an urgent need to address the issue of water pollution, which could have a serious economic impact if left unchecked. The Government is studying the feasibility of setting up a national body to manage the rivers as well as the creation of a national water council to improve federal-state government cooperation in water resources management.
- Malaysia Geography Collection on the Encyclopedia of Earth
- Department of Agriculture. 1994. Paddy statistics of Malaysia: Peninsular Malaysia, p. 124.
- Department of Environment. 1994. Environmental quality report. Malaysia.
- Department of Forestry, Peninsular Malaysia. 1994. Annual report. Malaysia.
- Department of Irrigation and Drainage. 1982. National water resources study, p. 7-14. Main Report, Vol. 1. Master Action Plan. Malaysia.
- Department of Statistics. 1997. Statistics handbook, p. 74. Malaysia.
- Economic Planing Unit, Prime Minister's Department. 1996. Seventh Malaysia plan. Malaysia.
- Neo, T.L. 1996. Proceedings of the regional seminar on integrated river basin management. Melaka. Malaysia, Vol.1.
- Water Profile of Malaysia, Food and Agriculture Organization.
- World Factbook: Malaysia, Central Intelligence Agency.
- Ministry of Agriculture & Agro-based Industry, Malaysia, Government of Malaysia
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