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| Sunday, 18 May 2003 |
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Environmental problems - Foreign construction contractors to blame by Elmo Leonard Excessive sand mining of rivers flowing out of the western province where development is most concentrated has lead to a spate of environmental problems which would cost many millions of rupees to rectify, research studies carried out by the Chamber of Construction Industry of Sri Lanka (CCISL) reveal. The worst situation lies along the Kelani river which runs through Colombo. Foreign construction contractors were most to blame for this environmental carnage having over-dredged the Kelani river to fill up Baseline Road, Colombo, with sand, during construction work a few years ago. Sand from the Kelani has also been used extensively to cover telecommunication and other infrastructure networks in recent years. Over-mining of river sand has been known for many years, to cause sea erosion. Colombo's environs are now left with loss of river banks along the Kelani heavy rain; loss of land; flooding due to faster movement of water following threat to drinking water supply schemes due to salt water intrusion resulting from the lowering of the river bed; the penetration of the salt water from the sea further inland that affects drinking and agricultural water supplies; the lowering of water table near rivers which in turn lowers levels in wells; the drying up of irrigational channels particularly in the Deduru Oya basin; consequent health effects among other problems, CCSL president, Surath Wickremasinghe told a media conference. Similar problems due to over-mining of sand by foreign construction contractors and others are also experienced along the Maha Oya, near Negombo, Kalu Ganga near Kalutara and Deduru Oya in proximity of Chilaw. A bund will have to be constructed inside the Kelani river to prevent saline water moving up-river, engineer Jaya Wickremetratne said. The over-dredging of river sand by unscrupulous foreign contractors is due to an absence of a construction policy in Sri Lanka, members of CCISL charged. Sea sand mined in Sri Lanka in the recent past had been carried out too close to the shore, causing sea erosion, a case in point being Wennappuwa, Wickremeratne said. Sea sand must be harvested from over six miles off the shore. A sea sand dredger would cost over $35 million, and the ones used here, have been hired. Off shore sand has been used recently for major landfill and road construction projects, notably Muthurajawela (5 million cubic metres) Colombo Katunayake expressway (4.5 million c.m.) Jaya terminal (1 million c.m.) and South Asian Gataeway (half million c.m.). Sri Lanka needs 7.3 million cubic metres of sand per year, according to the Gerry Byrme and Anura Nanayakkara report, on alternatives for river sand. The Western province would need 40 percent of that amount of sand; Central province 12 percent; Southern province 15 percent, Eastern 4 percent, North Western 10 percent, North Central 7 percent, Uva 3 percent and Sabaragamuwa 7 percent. Sea sand when dredged should be left for period of time to be desalinated by rain, before use. For storing a million cubic metres of sea sand, it would need 20 hectares of land. The Crow Island in Colombo 15, has been recommended. This island is composed of peat, and if a large weight of sand is stored here, the newly constructed multi- million rupee Crow Island housing scheme would collapse, engineers said. |
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