Who is to blame for falling Lake Victoria water level?
UGANDA has disputed a report pinning it on the mismanagement of the Lake Victoria water. The accusation has raised a pertinent question as to who is responsible for the dropping level in Africa’s largest fresh water lake.
By Gerald Tenywa
UGANDA has disputed a report pinning it on the mismanagement of the Lake Victoria water. The accusation has raised a pertinent question as to who is responsible for the dropping level in Africa’s largest fresh water lake.
Uganda has demanded a comprehensive study on water use by Kenya and Tanzania, the other two East African countries sharing the 69,480-square kilometre lake.
Between 2004 and 2006, the lake’s water level dropped by 1.5 metres, while its 3,200-kilometre shoreline receded by up to 200 metres in some areas over the same period, studies have shown.
While Uganda attributes the dropping level to several factors including climate change, Kenya and Tanzania blame the decline on the over-draining of the water for hydro-electric power production by Uganda.
To reduce the growing tension, the three neighbouring countries commissioned a consultancy firm two years ago to study the Agreed Water Curve (AWC) of the lake. The study would come up with a new AWC.
The study, jointly done by the UK Institute of Hydrology and the Tanzanian University of Dar-Es-Salaam, reportedly attributes the reducing water level — the lowest in 80 years — to the opening of the Kiira Dam, that more than doubled the amount of water released.
But Uganda pointed out several loopholes in the report and wants the study to cover the use of water by particularly Tanzania for irrigation.
“Uganda was not happy with the preliminary report of consultants because they concentrated on the release of water for production of hydroelectric power only,†an expert in Uganda’s Ministry of Water and Environment said.
“The other countries are also withdrawing water from the lake for irrigation, but the consultants had left them out.â€
Water and environment minister Maria Mutagamba said: “We need to know how much they are taking out and the implications. It is something we need to know before we consent to a new water release policy for hydro-electric power generation.
“It (study) should have been concluded, but because of this anomaly, the consultants have been given more time.â€
Prof. Tickodri Togboa of Makerere University Faculty of Technology says the water level was declining mainly because the inflow into the lake reduced by 40% between 2004 and 2006. He says this is a cyclical occurrence every 12 or 13 years and is likely to happen again between 2016 and 2018. “It is something, which Egyptian engineers predicted earlier.â€
He also says the loss of 10mm of the water level observed on a certain day in 2005 is equivalent to the release of over 4,000 cubic meters of water per second.
“This is four times the amount that was being used to generate hydro-electric power,†he says.
“The lake level should have dropped by only 3mm per day when both Nalubaale and Kiira are fully open. Kiira and Nalubaale combined have a capacity of 2,150 cubic metres per second. So the release of 4,000 cubic metres per second would have had an overflow and damaged the infrastructure, which was not the case. So other factors, mainly evaporation, were responsible for the water loss.â€
Kiira power station is an extension of Owen Falls Dam. At the commissioning ceremony in 2002, President Yoweri Museveni renamed Owen Falls Dam as Nalubaale power station.
At a rate of 10mm per day, Lake Victoria, on which up to 30 million people rely, would take just about 20 years to dry if the water was not being replenished. The average depth of Lake Victoria is 40 metres, while the deepest spot is 83 metres.
Togboa disclosed that since October 22, 2006, the lake level has gained by about one metre from 10.43m to now 11.4m and that the rise is expected to continue for the next four to five years.
Togboa said the other lakes within Eastern Africa (Rukwa, Tanganyika in Tanzania and Turkana and Nakuru in Kenya) also suffered dropping levels yet they are not used to produce hydro-power.
“This means the factors responsible for their water loss is also affecting Lake Victoria,†said an expert in the water ministry.
The only outlet for Lake Victoria, which is ringed by mountains, is at Jinja. Until 1954, the lake emptied into the Nile over a natural rock weir (barrier), but that year, British colonial engineers blasted out the weir and replaced it with the Owen Falls Dam, which effectively transformed the lake into a giant hydroelectric reservoir.
“At the time, engineers agreed that the amount of water flowing through the dam’s turbines should mimic the old natural flow over the weir. The formula, known as the “agreed curve†set a maximum flow of between 300 and 1,700 cubic meters per second, depending on the water level in the lake. The agreed curve remains in force today under a treaty with Egypt, the ultimate user of most of the Nile’s water,†says a recent report.
However, soon after building Kiira hydropower complex close to the first dam, the water level started falling sharply, to an 80-year low.
“There is a study, which we are working on and once it is done the new release policy will be developed,†Togboa said.
So far a draft has been prepared, but "it is not agreed on by all the countries." Asked when the new release policy will be in place, the expert says, “in about a year.â€
On accusations that Uganda was not sharing information on the water releases, Mutagamba said the Lake Victoria Commission was responsible for releasing the information, not Uganda’s Ministry of Energy or the World Bank.
“Giving information directly is like opening the doors to our bedroom.The issues of water are issues of security. There are standing agreements on how the information is supposed to be handled,†she explained.
UGANDA has disputed a report pinning it on the mismanagement of the Lake Victoria water. The accusation has raised a pertinent question as to who is responsible for the dropping level in Africa’s largest fresh water lake.
Uganda has demanded a comprehensive study on water use by Kenya and Tanzania, the other two East African countries sharing the 69,480-square kilometre lake.
Between 2004 and 2006, the lake’s water level dropped by 1.5 metres, while its 3,200-kilometre shoreline receded by up to 200 metres in some areas over the same period, studies have shown.
While Uganda attributes the dropping level to several factors including climate change, Kenya and Tanzania blame the decline on the over-draining of the water for hydro-electric power production by Uganda.
To reduce the growing tension, the three neighbouring countries commissioned a consultancy firm two years ago to study the Agreed Water Curve (AWC) of the lake. The study would come up with a new AWC.
The study, jointly done by the UK Institute of Hydrology and the Tanzanian University of Dar-Es-Salaam, reportedly attributes the reducing water level — the lowest in 80 years — to the opening of the Kiira Dam, that more than doubled the amount of water released.
But Uganda pointed out several loopholes in the report and wants the study to cover the use of water by particularly Tanzania for irrigation.
“Uganda was not happy with the preliminary report of consultants because they concentrated on the release of water for production of hydroelectric power only,†an expert in Uganda’s Ministry of Water and Environment said.
“The other countries are also withdrawing water from the lake for irrigation, but the consultants had left them out.â€
Water and environment minister Maria Mutagamba said: “We need to know how much they are taking out and the implications. It is something we need to know before we consent to a new water release policy for hydro-electric power generation.
“It (study) should have been concluded, but because of this anomaly, the consultants have been given more time.â€
Prof. Tickodri Togboa of Makerere University Faculty of Technology says the water level was declining mainly because the inflow into the lake reduced by 40% between 2004 and 2006. He says this is a cyclical occurrence every 12 or 13 years and is likely to happen again between 2016 and 2018. “It is something, which Egyptian engineers predicted earlier.â€
He also says the loss of 10mm of the water level observed on a certain day in 2005 is equivalent to the release of over 4,000 cubic meters of water per second.
“This is four times the amount that was being used to generate hydro-electric power,†he says.
“The lake level should have dropped by only 3mm per day when both Nalubaale and Kiira are fully open. Kiira and Nalubaale combined have a capacity of 2,150 cubic metres per second. So the release of 4,000 cubic metres per second would have had an overflow and damaged the infrastructure, which was not the case. So other factors, mainly evaporation, were responsible for the water loss.â€
Kiira power station is an extension of Owen Falls Dam. At the commissioning ceremony in 2002, President Yoweri Museveni renamed Owen Falls Dam as Nalubaale power station.
At a rate of 10mm per day, Lake Victoria, on which up to 30 million people rely, would take just about 20 years to dry if the water was not being replenished. The average depth of Lake Victoria is 40 metres, while the deepest spot is 83 metres.
Togboa disclosed that since October 22, 2006, the lake level has gained by about one metre from 10.43m to now 11.4m and that the rise is expected to continue for the next four to five years.
Togboa said the other lakes within Eastern Africa (Rukwa, Tanganyika in Tanzania and Turkana and Nakuru in Kenya) also suffered dropping levels yet they are not used to produce hydro-power.
“This means the factors responsible for their water loss is also affecting Lake Victoria,†said an expert in the water ministry.
The only outlet for Lake Victoria, which is ringed by mountains, is at Jinja. Until 1954, the lake emptied into the Nile over a natural rock weir (barrier), but that year, British colonial engineers blasted out the weir and replaced it with the Owen Falls Dam, which effectively transformed the lake into a giant hydroelectric reservoir.
“At the time, engineers agreed that the amount of water flowing through the dam’s turbines should mimic the old natural flow over the weir. The formula, known as the “agreed curve†set a maximum flow of between 300 and 1,700 cubic meters per second, depending on the water level in the lake. The agreed curve remains in force today under a treaty with Egypt, the ultimate user of most of the Nile’s water,†says a recent report.
However, soon after building Kiira hydropower complex close to the first dam, the water level started falling sharply, to an 80-year low.
“There is a study, which we are working on and once it is done the new release policy will be developed,†Togboa said.
So far a draft has been prepared, but "it is not agreed on by all the countries." Asked when the new release policy will be in place, the expert says, “in about a year.â€
On accusations that Uganda was not sharing information on the water releases, Mutagamba said the Lake Victoria Commission was responsible for releasing the information, not Uganda’s Ministry of Energy or the World Bank.
“Giving information directly is like opening the doors to our bedroom.The issues of water are issues of security. There are standing agreements on how the information is supposed to be handled,†she explained.