Conference: Hydro Power Africa
Location: Johannesburg, South Africa
Presenter: Sandy S Tickodri-Togboa
Abstract: Presented by Sandy S Tickodri-Togboa at Hydro Power Africa

Increasingly, the lakes of East Africa have been recognized as important indicators of environmental and climatic change. These lakes register the pulse of rainfall variability in the equatorial tropics. Among these lakes Lake Victoria has probably been of the greatest interest and received the most attention.

Interest in Lake Victoria water balance can be traced back to the 1920s. While many of the works that evaluated the lake’s water balance were in the context of further understanding of the Hydrology of the Nile, some of the recent studies have focused on the lake’s water balance as a proxy for obtaining rainfall values from the record of the lake’s levels. The waters originating from the lake provide hydropower through its only outlet, Victoria Nile River, at Owen Falls in Uganda, and other power plants downstream. These waters also support extensive irrigated agriculture schemes in Egypt, ecological values in Sudan and other wetlands, an important tourism industry on Nile River, and navigation and transport over large distances.

For a long period the threats that faced the lake were perceived to be eutrophication, over-exploitation of fisheries, the introduced exotic species and climate change. Recently, however, an alleged over-abstraction of water by the hydropower stations at Owen Falls Dam in Jinja, Uganda, has been added to the lot, together with other human activities. Indeed, when the lake experienced a severe nose dive between 2003 and 2006, all accusations were directed at the operators of the two hydropower stations at Owen Falls Dam. This was in spite of the numerous instances of similar nose dives in the past that occurred well prior to the construction of the two hydropower stations and which are well documented in the literature on solar-terrestrial physics.

In this paper, we demonstrate and argue that recent sharp declines of water levels observed on Lake Victoria, in particular, and on the other East African lakes of tectonic origin, in general, can hardly be linked to the intensification of human activities in the form of over-abstraction of the waters of the lakes by the operators of the hydropower stations at Owen Falls Dam. Rather, these were manifestations of the responses of the lakes to turning points of solar cycles that we should have expected. These will re-occur in the future and our challenge is to devise mechanism for adaptation to the consequences.