Nairobi — Two rivers, Nzoia in Kenya and Kagera in Tanzania, contribute 47 per cent of all the surface water that flows into Lake Victoria, but this has fallen sharply in the past five years
Focusing on water discharges by the Kiira and Nalubaale power stations as the principal cause of Lake Victoria's falling water levels, is diverting the debate from issues more critical to the long term health of the lake, say senior Uganda Water and Energy officials.
Regional environmental and global climatic issues pose a far greater threat to the lake as inflows from tributaries have fallen significantly in recent years, while the mean temperature has risen by 0.48 degrees centigrade over the past two years.
Coupled with the large surface of Lake Victoria (96,000km square), losses to evaporation have shot up, leading to the sharp drop in water levels, says Fred Kyosingira, the principal hydrologist in Uganda's Ministry of Water and Lands.
"We have been having very little rain and the forecast for this season remains bleak. We have seen widespread destruction of forest cover across the region. These factors are more pertinent to the current crisis over Lake Victoria than the discharges out of the Owen Falls Dam," Mr Kyosingira told The EastAfrican.
The debate comes on the back of seasonal climate forecasts by meteorological authorities in Kenya, Uganda and Tanzania that show that the region is likely to receive below-average rains during the long rains season expected to commence in a few weeks' time.
According to Mr Kyosin-gira, total inflows from the lake's tributaries have dropped by 40 per cent as a result of prolonged drought in the region while global warming associated with emission of greenhouse gases by Western countries is also a contributing factor.
There is a big environmen-tal problem that we are not talking about.
The environmentalists blaming Kiira power station have not quantified the impact of the drought because if the rivers were bringing in normal quantities, the level of the lake would not have gone down so much," argues Paul Mubiru, Commissioner for Energy in the Ministry of Energy and Mineral Development.
Two rivers - Nzoia in Kenya and Kagera in Tanzania - contribute 47 per cent of all the surface water that flows into the lake, but this has fallen sharply in the past five years.
While defending the Jinja power stations, Mr Mubiru showed The EastAfrican records of water levels from the Jinja flow meter for the 15 years between 1990 and 2005 which show that the lake level had hit low points even before the Kiira extension to the Owen Falls power station was commissioned.
According to the data, the water level fell to 11.27 metres in September 1997 before the unusually heavy rains pushed it close to 13m in May 1998.
Low points of 11.50m were registered in September 2000, two months after the first two units at Kiira had been switched on, but this was accompanied by a recovery two years later when the level rose above 12m.
The introduction of unit 3 at Kiira around the same time came in the wake of a fall in levels that was followed by a slight recovery that lasted until July 2003.
Mr Kyosingira said that since last month, the ministry had capped water discharges at the Owen Falls complex, where Uganda runs two power stations, to 850 cubic metres per second. This is the regime that will operate until a review, due in May, advises on whether further cutbacks should be implemented.
Power production at the complex, which has an installed capacity of 300 Megawatts has been scaled down to 135MW in the face of dwindling water volumes.The Ugandan officials' explanations come against the backdrop of reports depicting an unfolding catastrophe in several countries in the Great Lakes region.
An October 2005 IRIN report cited problems at Bujumbura Port resulting from a 5-foot drop in the level of Lake Tanganyika.
On March 3, news agencies quoted Tanzanian President Jakaya Kikwete telling the country that hydropower generation, with an installed capacity of 561MW, had fallen to just 167.5MW at the end of January before sinking to an all-time low of 50.5MW at the end of February.
"This is not just bad, it is scary," President Kikwete is reported to have said.