Interview

Why dams matter

Michael Abebe is the Regional Coordinator for Water Resources and Dam Safety at the Eastern Nile Technical Regional Office (ENTRO) and currently the Vice President of the International Commission on Large Dams (ICOLD). During the Nile Day celebrations in Sudan’s capital Khartoum on February 22, 2020, he spoke with Waakhe Simon Wudu about dams, why they matter and some pressing issues.

The Niles: What would you tell a South Sudanese person in Juba who does not know about dams in the region?

Michael Abebe: A dam is to regulate variability of flow in the river systems. If there is any variability in the Eastern Nile countries, there is a need to develop dams, because they regulate the flow during the rainy season.

Usually, in the Eastern Nile, the flow is mostly dominated by three or four months of rain starting from June or September, but the other months are very dry. There is a need for irrigation, energy, water supply and navigation. To ensure this water is available throughout the year, you need to develop a dam.

TN: Why do some countries in the Eastern Nile Basin region (South Sudan, Ethiopia, Sudan and Egypt) establish dams and others do not?

MA: To have a dam, you have to have the water resources, the topography and also demand for water. If there is a scarcity of water or the wrong topography in the area, you cannot build a dam. If the water is scarce and variable, you have to develop a dam to secure the water supply or to sustain irrigation or energy.

If you have a continuous flow of water in the river system, you don’t need to develop a dam. But when there are scarcity and variability of flow in the rivers, you need to provide a regulating mechanism, and that is often a dam.

TN: Do we have dams in the Eastern Nile Basin region, and if yes, where?

MA: We have more than 30 large dams in the Eastern Nile Basin region. Mostly these are located in Egypt, Sudan and Ethiopia. At the moment, South Sudan does not have a dam. But I know that there are dams in the pipeline for hydropower purposes in the future.

TN: What considerations need to be taken into account while constructing a dam?

MA: Proper planning and investigations have to take place before you begin construction. Luckily, we have a lot of experience around the world, and we can learn from that.

We have more than 30 large dams in the Eastern Nile Basin region.

First, you have to conduct proper studies, planning and even consultations. Unless you do this properly, you may repeat mistakes made by other countries. I suggest that South Sudan has to properly assess the possibility of constructing a dam in its river because there are other options rather than developing dams.

For instance, many dams are constructed in the region to provide energy. If there is the possibility of power trading with neighbouring countries, you don’t need to develop a power plant or a dam.

Or, if you have sufficient vegetation or rainfall in the region – for example, six months or nine months of rainfall per year – you may not need to develop your irrigation system. You have to make efficient use of the rain-fed system for agriculture.

TN: Are there basic other things to consider while planning to construct a dam besides environmental studies?

MA: Yes, when I say planning, it means the planning process in the study phase. This includes environmental and technical aspects, including whether the material is available to construct the dam itself and whether the foundation is strong enough for a dam.

Similarly, you have to explore the environmental and social aspects in that area. For example, you have to be careful if there is a high amount of displacement or resettlement.

TN: What advantages and disadvantages come with a dam?

MA: A dam has multiple benefits. It can be used for flood control, irrigation, recreation or navigation. However, it needs proper operation and maintenance. You need to monitor the safety or the health of the dam properly. If the structure is not maintained, you lose the benefits of energy or irrigation as well as maybe affecting the downstream communities.

So from the structural point of view and in terms of environmental and social aspects, you have to be very careful. However, dams also offer a wide range of benefits.