Lessons learnt from dealing with climatic extreme events - A case of L. Victoria and the White Nile Cascade

Abstract

Lake Victoria storage and water levels are affected by changes in precipitation, evapotranspiration, tributary inflows and outflow in the single Nile River outlet at Owen Falls Dam. In May 1964, the lake reached its first highest recorded level of 13.46 m at the Jinja Pier that resulted into the Nile River outflow of 1910 m3/s. Consequently, the decision to construct Owen falls extension later in year 2000 was motivated by the risk assessment to mitigate the potential of regional hydrology reverting to the 1960s conditions. However, the catchment has consistently had above-normal precipitation coupled with accelerating land use changes that have resulted into higher inflows from the lake tributaries. In May 2020, the lake level surpassed the 1964 record, peaking at 13.47 m towards the end of May. These two occurrences (1964 and 2020) greatly affected hydropower generation, disrupted socio-economic activities around the lake and along the river and posed a threat on the safety of Nile Cascade dams. This paper therefore, presents the integrated multi-sectoral framework that was adopted to assess and mitigate the risks involved. The paper also identifies challenges, opportunities, interventions and lessons learnt from such risks and uncertainties.