INGENIEUR JAN-MAR 2017 Vol 69 2017 | Page 44

INGENIEUR
INGENIEUR
Period
No. of Dams Built
Period
No. of Dams Built
≤ 1900
3
1901 – 1910
1
1961 – 1970
10
1911 – 1920
0
1971 – 1980
6
1921 – 1930
2
1981 – 1990
28
1931 – 1940
9
1991 – 2000
12
1941 – 1950
2
2001 – 2010
18
1951 – 1960
3
2011 – 2016
12
Table 2: Dams Built In Various Periods
Distribution Of Dams According To Function, Age, Dam Type and Hazard Rating
Table 1 shows the distribution of 106 dams built by various Government agencies and private developers for various purposes throughout the country. The owners of most dams are federal ministries and state statutory bodies. Private developers and mining companies are also involved in dam development.
Besides the 106 dams listed in Table 1, there are around 10 dams built by private companies for various purposes, such as storage of mining waste( tailing dams) and water supply in agriculture plantations. There are also dams built for storage of sludge from water treatment plants and storage bunds built for water supply and storm water detention.
Distribution of Dams According to Function Over 60 % of the dams in the country were built for water supply purposes. There are 65 water supply dams out of a total 106 dams in the country. There are 15( 14.1 %) irrigation dams, and 16( 15.1 %) hydropower dams. There are four( 3.8 %) dams built for flood mitigation purpose, four for silt retention and two for recreational purposes.
Distribution According to Hazard Ratings of Dams There are 48 dams which fall under the category of significant and higher hazard rating based on the current guidelines. At least 20 dams are located close to urban centres mostly due to downstream development.
Distribution of Dams According to Age There are four dams over 100 years in age, which is generally taken as the design life span of dams. There are 20 dams over 50 years old. There are a few dams that have been decommissioned, e. g. Asahan Dam in Melaka and Berapit Dam in Penang. There are also dams where their functions have changed, for example Ayer Keroh Dam in Melaka, changed from water supply to recreational purposes. The distribution of dams built in various periods is shown in Table 2.
Distribution of Dams According to Dam Type Table 3 shows the distribution of dams according to the type of design. Seventy( 66 %) of the dams built in the country are of the earth fill type. In recent years there is an increasing number of Roller Compacted Concrete Dams being built.
Item
Dam Type
No.
Percentage
%
1
Earth fill
70
66
2
Rock fill
14
13.2
3
Concrete gravity
18
17
4
Others
4
3.8
Table 3: Distribution of Dams According to Dam Type
42 VOL 69 JANUARY-MARCH 2017