The Gibe III Dam
The Gibe III dam, now under construction in the middle basin of the Omo-Gibe, will be the tallest in Africa and will double Ethiopia’s electricity generating capacity. But although it will have relatively little impact on the population of the reservoir area, it will have a potentially devastating impact on the 90,000 or so mainly agro-pastoral population of the flood plain downstream. This is because, by regulating the flow of the river, it will eliminate the annual flood and make possible large-scale commercial irrigation schemes in the lower basin.
All the residents of the lower Omo depend on flood-retreat or recession agriculture. Those who live in the more arid southern part of the lower basin also depend on the flood for the annual rejuvenation of their dry-season pastures. These facts were ignored by the original environmental impact assessment (EIA), which was completed in 2006, the year dam construction began. Two years later, a revised ‘Economic and Social Impact Assessment’ (ESIA) was produced, together with an ‘Additional study’ devoted to downstream impacts.
It was now proposed to release an annual ‘controlled flood’ from the dam reservoir which, it was claimed, would fully compensate for the loss of the natural flood and be the centre-piece of a new ‘downstream mitigation plan’. The likely effectiveness of the controlled flood, however, was quickly and comprehensively demolished in an independent review of the Gibe III project commissioned by the European Investment Bank (EIB) from the French consulting firm, SOGREAH. This concluded that the controlled flood had been planned without a proper study of the problem it was intended to solve, that information needed to design an effective downstream mitigation plan was ‘still dramatically missing’ and that a number of further studies were needed to fill the gaps. Following the decision of the Industrial and Commercial Bank of China, in July 2010, to make a loan of 450,000 USD to the project, the EIB decided against making a loan itself and the recommended further studies were not carried out.
In the same month that the SOGREAH review was completed (March 2010), it was revealed in a press release issued by the construction company, Salini Costruttori, that the controlled flood would not in fact be a permanent measure but would be withdrawn ‘when deemed appropriate’. The dam builders, therefore, had a very different understanding of the role of the controlled flood from that of the authors of the ESIA. For the latter, it was to be the central component of the ‘downstream mitigation plan’. For the former, it would operate only for a limited period, after which flood-retreat cultivation would stop altogether, dry season grazing areas would no longer be sustained by the annual flood and the local population would take up ‘more modern’ (presumably irrigated) agriculture.
It was another 10 months before it became clear what was actually planned. In a speech given in Jinka, the capital of South Omo Zone on 25 January 2011, the then Prime Minister, Meles Zenawi, announced that the Ethiopian Sugar Corporation would soon begin work on a 150,000 ha irrigation scheme in the Lower Omo. This would be made possible by the elimination of the Omo's annual flood and the 'uplifting' of it's dry season flows by the dam.