The FAO-ESCAP pilot project on national water visions. From vision ...

<strong>The</strong> increased demand for the limited and diminishing supply of clean water available has led to
competition among the various water users, a competition the continued economic growth exacerbates
increasingly. In addition, as the readily available portion of water resources has already been
developed for use in practically all regions of major water demand, future water resources
development will require the construction of more storage dams. <strong>The</strong>se are not only costly to build:
there’s a high price to pay in environmental terms as well. Furthermore, the practicable limit of
surface water resources development has been reached in some regions of high demand, and it has
become necessary to consider inter-basin and interstate surface water transfer schemes.
c) Increased flooding problems
Ironically, at times of water shortages, parts of Malaysia face significant flood problems. Although
floods are natural phenomena arising from excessive rainfall overwhelming existing waterways for a
while, uncontrolled development activities in watershed areas and along river corridors can increase
the severity of floods. <strong>The</strong> high rate of sedimentation in the rivers has adversely affected their
drainage capacity, leading to more frequent floods in downstream areas and to more intense flooding.
Incidences of flash floods in urban areas are on the rise due to the runoff characteristics of built-up
areas.
<strong>The</strong> high rainfall during the monsoon results in large areas being subjected to flooding. It has been
estimated that altogether about 29 000 km 2 or nine percent of the total land area of Malaysia are floodprone,
affecting some 12 percent of the population. <strong>The</strong> average annual flood damage was estimated
at RM100 million in 1980, but this has increased due to urban expansion and the escalation of land
and property prices.
Absolute control over floods is rarely feasible either physically or economically. However, flood
mitigation measures are undertaken to reduce flood damage to a minimum, consistent with the cost
involved. Besides the construction of dams and reservoirs and the improvement of river systems,
measures to increase infiltration and to store the excess water in small ponds and retention basins are
being promoted. <strong>The</strong> Department of Irrigation and Drainage produces a storm water management
manual to address the incidence of flash floods in urban areas.
d) Environmental degradation
<strong>The</strong> development of public utilities such as water supply, sewerage, and urban drainage and flood
mitigation programmes helps to promote economic growth and improve the quality of life. However,
this economic development and the resulting rapid urbanization and industrialization have given rise
to problems of increased water pollution.
<strong>The</strong> main sources of organic water pollution are domestic and industrial sewage, effluent from palm
oil mills, rubber factories and animal husbandry. Mining operations, housing and road development,
logging and clearing of forest are major causes of high concentration of suspended sediments in the
rivers. In several urban and industrial areas, organic pollution of water has resulted in environmental
problems and adversely affected aquatic life. In addition to organic wastes, rivers remain a convenient
means of solid waste disposal. A major portion of household refuse which is not collected, burnt or
buried finds its way into drains and rivers. In the Klang Valley, an estimated 80 tons of waste ends up
National water visions in Southeast Asia 33