Drinking water from Nuwara Eliya’s Gregory Lake could pose a serious risk to human life and could even be fatal, according to Central Environmental Authority findings cited by MP Manjula Suraweera Arachchi, Chairman of the Nuwara Eliya District Coordinating Committee.
He made the remarks on the basis of reports the Central Environmental Authority presented to a recent District Development Committee meeting.
The readings
Authority data put the lake’s phosphate level at 1.04 milligrams against a normal level of around 0.20 milligrams — roughly five times higher. Nitrogen stands at 3.70 milligrams against a normal figure of about 0.50 milligrams, more than seven times higher. Biochemical oxygen demand has risen to 9.72 milligrams.
Biochemical oxygen demand measures how much oxygen decomposing organic matter consumes; a high reading indicates heavy organic pollution and water that can no longer support normal aquatic life. Elevated phosphate and nitrogen are the classic signature of nutrient enrichment, which drives algal growth and further depletes oxygen.
Ada Derana’s report did not state the units for these figures or the sampling dates, and did not specify which parts of the lake were tested.
Silted feeder reservoirs
Gregory Lake was built during the British colonial period and was originally fed by several small reservoirs. Those feeder reservoirs have silted up over time, the MP said, allowing pesticides, fertilisers, other chemicals and waste from up-country agriculture to enter the lake directly and dangerously alter its water composition.
Nuwara Eliya District is the centre of Sri Lanka’s intensive upcountry vegetable cultivation, which uses heavy applications of synthetic fertiliser on steep terrain that drains rapidly into watercourses.
The MP said the Ministry of Environment, the Urban Development Authority and the Irrigation Department are working through a joint committee to plan further measures to address the situation.
No public health advisory against contact with the water has been reported, and Gregory Lake remains one of Nuwara Eliya’s principal visitor attractions, with boating and jet-ski operations on the water. The lake was the site of a jet-ski accident that prompted a naval rescue on August 17. It is unclear whether the readings will affect recreational use.
