After effects of the Mahaweli Development scheme (MDS) " Hyper Eutrophy"

After effects of the Mahaweli Development  scheme (MDS) " Hyper Eutrophy"

            The MDS commenced in 1969 and after 48 years of its existence, whatever merits the government claims from the MDS, the government is frantically fighting a single handed battle, especially in the North central province (NCP) against Chromic Kidney Disease (CKD) , with all sorts of Internationally assisted 'remedies' and payments of Rs. 5000/- per patient monthly, to about 20,000 patients the majority of whom are now incapacitated for life and uncertain of a prolonged existence.

            During  the times of the ancient Sinhala Kings,  Mahaweli Water was supplied  to the dry zone by diverting the waters of the Amban ganga by four anicut across it and its tributaries and of the Mahaweli by two anicuts across it. As the entire upper catchment of the Mahaweli Ganga, inclusive of the Amban Ganga  in the hills of the wet and intermediate zone, was in primeval forest, all the water diverted was without any contamination.

            In comparison, the water now diverted from the ' Mahaweli'  to the dry zone in highly polluted due to waste water from the Tea estate settlements, villages, towns and cities (example ' The Kandy City Drain' along Gopallawa Mawatha.) and the washed down pesticides, weedicides, fungicides and fertilizers from Tea estates, potato and vegetable cultivations in the wet and the intermediate zones.

            As the Mahaweli water diverted in ancient times was free of chemicals and the wastes of human settlements, it was not injurious to health and there was no growth of floating water weeds in tanks, channels and paddy fields as there were no chemicals in the water. This condition  of the quality of water in known as low eutrophy.

            At present, every poison imaginable except Radioactive wastes, is added to the                   ' Mahaweli' and its tributaries by the vast population within its catchment area

·         Households and hotels

·         Dispensaries and hospitals

·         Factories and sawmills

·         Service Stations and garages

·         Electronic repair shops and laundries

·         Markets And Farms

·         Slaughter houses and processing plants for chicken, mutton, pork and beef and fish stalls,  

·         Pirating toilet outlets and road  waters,

·         Vehicle emission gases dissolved in rain water

·         Printed colour notices pasted on roadside walls etc....

Once in the water, uncountable numbers of toxic chemicals get accumilated in a never ending process. The situation prevailed even when the Mahaweli Project plans were prepared from 1964 to 1968. Weedicides, pesticides and fungicides contribute poisonous organic compounds with residual activity. The inorganic chemicals in fertilizers added to Tea, Potato and Vegetables ionise in water to produce ' free' ions such as phosphates and Nitrates, which are attracted to metallic ions such as cadmium, lead etc...which come with the waste water from towns, cities, Therefore, the Mahaweli becomes a 'deadly cocktail' which proceeds into the dry zone.

            This deadly cocktail enters the dry zone via the Polgolla diversion, Elahera, Angamedilla, 'Vienna Ela' and Moragahakande, As the Mahaweli, water gets distributed all over  (for example from Polgolla diversion to Kalawewa, Kala wewa Nuwarawewa Yoda ela, Cascade systems of tanks and tracts of paddy fields), the chemical poison content in the smalls tanks and paddy fields rise, creating ' hyper eutrophy' which manifests itself by the luxuriant and uncontrollable growth of floating water plants throughout the dry zone. The Gregory's lake at Nuwara Eliya in a good example of hyper eutrophy created by the waste water of the Nuwara Eliya town settlements and the  leached  fertilizers, pesticide, etc... from cultivations in its catchment area. (The lake in continually cleaned to remove these) Cadmium ions, phosphate ions, and cadmium phosphate molecules get deposited in the tanks, tank beds, fields of the dry zone, even in the adjacent highlands through their movement in soil moisture and the water table. Some of the major tanks in the NCP are already hyper-eutrophic and are partly covered with floating water plants.

            Already many tracts of Paddy land and small tanks in system H, which has been served with the deadly 'Mahaweli cocktail' since 1989 from Polgolla, show  signs of ' hyper eutrophy' which would be indicative of higher levels cadimium phosphate in the soil environment of system H. Lotus rhizomes in these tanks are suspected to carry traces cadmium phosphate. Therefore, the 'deadly cocktailed Mahaweli waters' is today not a boom but the 'Frankenstein Monster' to the dry zone of Sri Lanka.

Yasantha the Silva

B.Sc (Agriculture)