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| Sunday, 27 November 2005 |
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Features |  |
| News Business Features Editorial
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Environment For construction ... Off-shore sand equally good as river sand by Shanika Sriyananda
Finding and popularising alternatives to river sand are the very crucial need of the hour to save the country's rivers while meeting the rapid increase in demand for sand mainly after the tsunami. The tsunami housing reconstruction and reclaiming that washed out coastal belt need huge quantities of sand. Supplying sand for these two major requirements and meeting the annual demand for sand, which is nearly eight million cubic metres, is a gigantic task which needs urgent solutions. Apart from this, the immense damage to rivers caused due to over extraction of river sand also need urgent attention. The rivers that are abused are Kelani, Kalu, Ginganga, Ma Oya and Deduru Oya. Among them, the Kelani Ganga and Ma Oya have been mined for river sand far beyond the capacity and Deduru Oya is now under a serious threat. Over 4 million cubic metres are being mined from these rivers annually. According to H.G.S. Ariyaratne, Scientists of the National Building Research Organisation (NBRO), the rate of sand mining far exceeded the rate of natural replenishment of sand in the rivers. "Though sand mining in these rivers is totally banned, it will take another 75-years to heal and to come back to their original status. Otherwise, there would be no sand in the rivers in the future, to mine", he says. Myth He says that of the four alternatives - sand deposits, sand dunes, off-shore sand and manufactured off-shore sand is the most viable and best alternative to river sand. " Sand deposits can be mainly found in paddy fields and these are suitable for plastering of walls but these very thin sand needs more cement in the mixture. Exploring sand dunes are not environmentally suitable because they act as a wind barrier", Ariyaratne adds. According to him, off-shore sand is better for construction industry and also to prevent the rivers being mined rapidly. " But, still people have a myth or a suspicion about off-shore sand, that, it is not good for construction due to its high chloride content. Really this is a myth", he claims. The major environmental impact of river mining is coastal erosion. Due to this, supply of sediments to the shore from the rivers are drastically reduced. Sand mining in a river also lowers its bottom. The restriction of sediment flow increases flooding from the sea and changes the water quality to the detriment of the aquatic fauna and habitats. Apart from land destruction due to coastal and river bank erosion, drinking water resources are also under severe threat. Impacts on irrigation water will cause losses to agriculture and also damage the infrastructure. The salination of Colombo's drinking water due to the intrusion of sea water into the rivers was a another major impact that reported last year and this resulted in banning sand mining in the Ma Oya and Kelani River. Now the river beds have been deepened and the limited sediment transport from its upper reaches has resulted in a heavy coastal erosion along the Northwest coast and the intrusion of saltwater to the main water intake at Ambatale. The annual sand requirement of the country is nearly eight million cubic metres and it is growing at an annual rate of 10 to 15 per cent. Of the total, over 77 per cent of sand is consumed by the four provinces - Western, Southern, Central and North Western. Being the major sand consumer -the Western province needs 2,930,000 cubic metres or 40% of sand of the total country usage. The second major sand demand comes from the Southern province, which needs 1,100,000 cubic metres and this amount has been increased after the tsunami. "According to our projections, the rate of sand consumed by these four provinces will increase considerably", Director Coast Conservation Department (CCD) Dr. R.A.D.B. Samaranayake says. Over-mining at Kelani According to Dr. Samaranayake, these losses have been estimated to be in excess of Rs. 600 for every cube of sand mined from the rivers. The Western province loses over Rs. 600 million annually from damages caused by coastal erosion. " Our studies have found that the quantities mined from these rivers - Kelani ganga, Kalu ganga, Deduru Oya, Ma oya, Gin ganga and Nilwala ganga- during the period 1984 to 1998 is around 4 million cubic metres. In early years, sand mining in the rivers was a manual operation and the main method used was underwater mining, using barges, buckets and baskets. Surface mining using tractors is another method used where sand is available at dry spots in the river beds, where the river banks are not steep", he points out. According to Dr. Samaranayake, the CCD scientific investigations predict the Western province will suffer a severe shortage of river sand due to over mining of sand in the Kelani River. Several studies and researches have shown that the off-shore sand, which is now in use world over, is the major substitute for river sand and the country's potent to harness it from the sea. The National Sand Study, which issued the report in 1992 gave a clear warning signal on the need to cut down the rate of river sand mining and the need to introduce alternatives to river sand. In another comprehensive study, in 1999 by the NBRO, which did research on alternative sand showed the potential of off-shore sand, dune sand and crushed rocks as viable alternatives. The study conducted by the Coast Conservation Department in 2000 with the assistance of the Moratuwa University had also come up with the similar solution to river sand. "The study identified off-shore sand as the only feasible alternative, which is used in many Western and Asian countries for construction purposes", he said adding that the study conducted by the University of Moratuwa, which did a series of tests on off-shore sand, proved that off-shore sand is upto the standards set for construction purposes. High quality However, after the tsunami a ray of hope is glittering in the horizon with the efforts of Land Reclamation and Development Authority (LRDA) to popularise off-shore sand. A stock pile of over 300,000 cubes of off-shore sand is stocked at Kerawelapitiya, Muthurajawela and the LRDA is now distributing lorry loads of off-shore sand at a reasonable price. "The chloride content is very low in this stock as it has been exposed to rain for several years and was pumped 10 kilometres away from the beach. This sand is now in high quality compared to river sand", Chairman LRDA Somaweera Chandrasiri says. According to him, normally the chloride content of off-shore sand is 0.075 per cent but it is 0.01 in sand at Muthurajawela. This sand was pumped out to construct the Colombo-Katunayake Express way. The LRDA provides transport free of charge for those who purchase off-shore sand stocked at Kirimandala Mawatha in Narahenpita and the cost of a cube will be Rs. 3680 with VAT. "A permit from the Geological Survey and Mines Bureau (GSMB) is needed to transport sand and the GSMB officers will issue permits at site", he says adding that sand could be transported through the railway for tsunami housing projects. According to Chandrasiri, strength of the concrete is much higher when using off-shore sand than river sand. An international company has now been awarded the contract to dredge off-shore sand in the West coast of the country and the dredging will commence in end November. Over two million cubic metre will be pumped from the sea during a period of four months. "The newly dredged sand and the present off-shore sand stock will be enough to cater to the demand of off-shore sand, which is growing slowly, for the next five years", he adds. However, abundant availability of off-shore sand at low price in future would definitely bring better days for the construction industry, while opening the doors for local companies for a new avenue. Bird sounds of Sri Lanka The Bird Sounds of Sri Lanka an audio tape which features over 100 species of birds in eight habitat types, was released recently.
This unique work by Warakagoda covers the birds found in rainforests marshes, lagoons, town gardens, hills, dry forests, grasslands and scrublands and the dry zone. "I firmly believe that the sounds of these innocent birds will make a difference in the listener's attitude and will inspire them to respect and conserve the places where these sounds are coming from" says Warakagoda. All the sounds in this compilation were recorded in the wilds and in the relevant habitat types, by Deepal Warakagoda from 1999 through 2004. The Locations were: Sinharaja, Kitulgala Forest Reserve, Ratnapura, Bellanvila-Attidiya Sanctuary, Kalametiya, Tissamaharama, Bundala, Yala Blocks I, III and IV, Udawalawa, Sigiriya, Nilgala, Nuwara Eliya, Horton Plains and Udahamulla near Nugegoda. The compilation presents 105 species of birds including 19 endemic to Sri Lanka. They are classified as residents, endemic and migrant birds. Preventing floods: a crying need It was non-stop rain. The unusual gloomy weather brought some warning signs to many residents in the Western, Sabaragamuwa and the North and East except for villagers in some areas in Sabaragamuwa Province, who were frequently marooned by floods, but did they realise their hard earned money invested in properties would be 'drowned' in this rain water. Sharp at 3 am last Tuesday my phone rang and my mother was on line. "Please do not try to come here, we are under water", the line got cut off due to the heavy thunder that struck the north of the sky. No way of contacting her and unable to go beyond Delkanda junction my husband and myself waited anxiously till 7 in the morning. With no policemen on the road, the people have placed a few barricades using broken chairs covered with red cloth to block the road giving warning signals about the floods. Without heeding to their warnings, we drove our vehicle a few metres. People, some carrying the sick and infants, were walking to safer places drenched in the heavy rain. Some vehicles were stalled midway as the flood water had seeped into the silencer. No way of driving further we decided to walk. The umbrella was of no help. People warned us not to go ahead as the water level was increasing and the rain turning severe. But, our 'mission' was to take some food to my parents who were marooned. The flood water was, more than three to four feet and the whole area was a large pool. The famous canal, which was used as a short cut to Kotte during the Portuguese era and which flows along the Old Kesbewa Road, Rattanapitiya via Delkanda had disappeared. This canal which was so much wide and retained flood water has been narrowed and encroached by the residents today. With no seasonal 'excavation' to clean the canal which was clogged with all kinds of waste thrown by the residents. From a small hut to a mansion, the flood waters had given them equal treatment. With no difference they were all under water to an equal height. Chairs and small tables belong to the roadside montessori were floating and the swings were wrapped up with sili sili bags showing the gravity of the polythene menace. The massive garbage dump with all kinds of toxic materials had equally distributed its garbage and they were floating as well as melting in flood water. The stench was unbearable but people did not care as long as they wanted to save their lives. A part of the marshy land, I do not know whether it is a private land or state land, which was filled with 'dirty' soil mixed with all sort of waste including polythene was under water. The area is now loosing another land which sucked flood water for years. The plastic bottles, sili sili bags, polythene sheets, all kinds of non biodegradable materials and some waste materials which are not ethical to throw into an open garbage dump were floating around us. Nowhere to go, most people, except those who climbed upstairs carrying what ever their valuables they could carry, were inside their houses filled with flood water. Every one who spoke to us blamed the politicians and said that they would never give their votes unless they come up with some solutions. After a one and half hour journey (usually it is just a 20 minutes walk) we handed over the 'precious bag' to my parents who too had climbed upstairs for their lives. The whole house was under water. Anyway the water level had receded the next day. The authorities can say that it is a natural phenomena due to low pressure development in the Bay of Bengal or a seasonal occurrence. And some were happy that the damages have been low and nearly 49,000 were affected. The government will provide some relief packages and also pay compensation. Leave aside the natural occurrences. Even with a heavy shower of few minutes, most parts of the cities including the country's capital, go under water. The country needs a systematic solution, not short term patches but long term solutions to control floods and the proper disposal of garbage. It also needs some strong policies to prevent illegal filling of marshy lands and paddy fields. The new Cabinet has some new portfolios. Then why not we have separate Ministries to manage flood and garbage control. |
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| Produced by Lake House |
The excessive river sand mining to meet the demands from the growing
construction industry during the past two decades has created a serious
shortage of sand in the country. River sand is now fast disappearing due to
extraction of millions of cubic metres annually. The present sky rocketing
sand prices range from Rs. 5,000 to 7,000 a cube have hindered the growth of
the construction industry as well as the poor man's dream of building a
house of his own. 
Deepal Warakagoda who recorded these birds' sounds gives the listener a
chance to feel the real sense as being inside a nature reserve filled with
chirping sounds of our feathered friends. 
