Arusha — Lake Jipe has shrunk by 60 percent since 1970.
Three inland lakes and a water reservoir for hydro power generation in Arusha and Kilimanjaro regions are among the shrinking water bodies in Tanzania.
The minister of State in the Vice President's Office in charge of environment Prof. Mark Mwandosya says he is worried with the speed in which some inland lakes in the country were shrinking.
He told stakeholders in the environment sector from Arusha, Kilimanjaro and Manyara regions in Arusha recently that if measures are not taken urgently to save them, some lakes could disappear because of both natural and human-induced causes.
Prof. Mwandosya cited lakes Manyara, Jipe and Natron on the Tanzania/Kenya border and Nyumba ya Mungu dam in Kilimanjaro region as the most threatened water bodies in the country.
According to him, Lake Jipe used to support up to 10,000 fishermen until the 1960s but its size has shrunk by 60 per cent since 1970 due to siltation and growth of some weeds. The fresh water lake currently covers 28 square kilometres.
He did not mention the size of Lake Natron but revealed that the alkaline lake, famous for production of soda ash, had its size reduced by 65 per cent over the years due to a combination of factors including siltation and drought.
Prof. Mwandosya added that the weeds that had choked Lake Jipe have now spread to the adjacent Nyumba ya Mungu dam. The two water bodies are within the same drainage basin and are only 20 to 30 kilometres apart.
He warned that the shrinking of the dam could impact negatively on the country's energy supply. Nyumba ya Mungu is a reservoir for Hale and Pangani hydroelectric power stations downstream.
The two stations generate up to 20 per cent of the hydropower produced in Tanzania. Following the near collapse of fishing activities on Lake Jipe, many fishermen have shifted to Nyumba ya Mungu. The same weeds seen in the former are now encroaching the dam, the minister added.
He explained a national strategy for the conservation of lakes, rivers, sea environment, wetlands and other water bodies was in pipeline.
The lakes to be covered are both the fresh water and alkaline ones and those within the country's boundaries and lakes shared with neighbouring states.
He cautioned that conservation strategies of shared lakes may take time because neighbouring countries have to be consulted. Lake Jipe, Natron, Victoria, Tanganyika and Nyasa and rivers which cut through common boundaries of nations are the ones needing consultations of other countries.
The minister appealed to the stakeholders not to take protection of water sources and lakes for granted because if the problem is downplayed some water bodies can disappear after some years. He cited Lake Chad which has shrunk to only 1,500 square km from 26,000 square km in 1960.
However, prof. Mwandosya emphasized that conservation strategies for water bodies should be based on scientific research findings.
"We should use the expertise of our scientists in the academic and research institutions to arrive at solutions" he explained.