16 January 2021
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SNAS Statement on the 2020 Floods in Sudan

SNAS Statement on the 2020 Floods in Sudan


Most of the Sudanese Communities neighboring the Nile and its branches have suffered huge loss of properties and lives due to the catastrophic floods that occurred within August and September 2020. According to the National Council of Civil Defense of Sudan and UN sources as of 21 September, 730,000 persons were affected including more than 130 deaths, more than 100,000 houses and 150 schools damaged. This in addition to the health threatening sanitary situation created as a result of the flood water mixing with the destroyed poor toilet systems as well as health threatening conditions due to increased potential for spread of vector-borne disease near most of the houses in these poor communities. The disaster arrived on the wake of a heavy pressure from COVID-19 demands on a highly stressed economy forcing the Transitional Government of Sudan to immediately declare a state of emergency.

 The floods were mostly due to heavy rains in the Ethiopian plateau. To the hydrologist, the water levels recorded in Khartoum are comparable or even more than the levels corresponding to the record floods of 1946 and 1988. On the other side, the experts in climate blame these high rainfalls within the Ethiopian plateaue ( source for Blue Nile, Sobat, and Atbara) to the La Nina (phenomenon in the equatorial Pacific Ocean characterized by a negative sea- surface temperature departure from normal in the region 5°N to 5°S, 120°W to 170°W) effect within the tropical Pacific Ocean which is associated with greater rainfall in the Ethiopian plateau. Conditions on both, Pacific and Indian oceans were conducive to excessive rainfall over Ethiopia. Satellites observations confirm occurrence of above average rainfall conditions over Ethiopia during the last week of August. Although levels of Lake Victoria and Lake Kyoga are currently higher than average, the relative role of these White Nile sources in contributing to the flooding event in Sudan, if any, is unknown and would require further confirmation. Building national capacity for seasonal forecasting of floods/droughts in Sudan using teleconnections to the tropical oceans should be a priority for water resources management in Sudan.

 Though a natural phenomenon (La Nina) was the main cause of these current floods and associated hazard, yet the modest to weak preparedness, through earlier warning facilities and soft and hard protection facilities by these communities to such extreme natural events increased vulnerability significantly resulting the high level of damages. The level of disaster has been increased in some localities due to man-made land-use interventions within the normal courses of these water streams and their flood plains. Empowerment of the Sudanese National Council of Civil Defense to prevent such interventions in the future is a top priority and recommendation.

Seasonal flooding and rainfall is often associated with outbreaks of vector-borne diseases, mainly malaria. The water  pools created by rainstorms act as breeding sites for Anopheles mosquitoes which spread malaria. Proper source control measures are recommended for enhancing public health strategies all over Sudan especially following the rainy season. Extreme rainfall events and excessive flooding, however, are often associated with outbreaks of Rift Valley Fever (RVF) in Sudan. RVF is a viral disease transmitted by Aedes mosquitoes that are capable of vertical transmission resulting in infected eggs that may remain dormant in the environment for years until hatching occurs triggered by excessive rainfall events, resulting in infected mosquitoes that start a cycle of transmission among animals, with the help of the large populations of Culex mosquitoes. Humans in direct contact with animals or their meat get infected too. In response to any RVF outbreak, it is advisable to identify spots of small early outbreaks; isolate affected animal population taking strict action; educate the public in surrounding areas; and adopt a high level of transparency informing the local and international markets.”

One of the most recent relevant studies to this situation is in the 2020 Word Water Development Report (WWDR) publication from UN-WATER and UNESCO entitled “Water and Climate Change”. Quoting from this report “Climate Projections indicate with high confidence that extreme precipitation events will become more intense and frequent in many regions, but also that heat-waves will occur more often and last longer. The former will increase global flood risk, while the latter is expected to make droughts more intense”

 This report included a chapter on “Regional Perspectives” and Sudan was included within West Asia and North Africa. It described areas with highest vulnerability to climate change” are in the Horn of Africa, the Sahel and the Southwestern part of the Arabian Peninsula”. Based on projected change in water availability and adaptive capacity, Upper Nile Valley, part of Arab Peninsula and Northern part of the Horn of Africa are the most vulnerable. The following are some of the priorities issued within Arab Regional Consultation on Climate Change for the 2019 Arab Forum for Sustainable Development :

  • Development of flood risk
  • Sustainable urban
  • Enhancing data, research, and
  • Establishment of an early warning system so that communities are warned in
  • Increasing the resilience of vulnerable communities exposed to floods and droughts.

The report includes a chapter focusing on linkages between climate change adaptation and disaster risk reduction, highlighting opportunities to build more resilient systems through a combination of “hard” and “soft” measures.

The above short review indicates that Sudan is going to see more of such extreme events of floods and droughts. Therefore, any national preparedness should be focused on mitigating or adapting to floods and droughts which are expected to be more frequent with the progressing climate change. Flood disasters usually attain more attention due to their instantaneous damages. However, to many sources in the literature, droughts are more killers than floods in the long run.

The recommendations mentioned above from the Arab Forum could form a base to build on to establish an effective network of stakeholder to prepare a national strategy based on scientific data and research to deal with these challenges minimizing the risks and increasing the benefits through innovative initiatives including water harvesting and management of artificial groundwater recharge.

While the Grand Ethiopian Renaissance Dam (GERD) will significantly reduce the risks of flooding in the Blue Nile system and to some extent the main Nile, catastrophic flood risks will continue to occur within other rivers, tributaries, low lands in almost all parts of Sudan, including the Dinder and Rahad as well as related Wadis.

Addressing flood mitigation plans from regional perspectives offer an opportunity for win-win interventions and collaborative effort in data sharing, joint operation of current and future reservoirs such as GERD and Roseries Dam. The Eastern Nile Flood Preparedness and Early Warning Project, as one the Subsidiary Action projects completed in 2011, contributed significantly as an attempt to produce pilot interventions for flood mitigations in the eastern Nile. Among these are:

  • The production of flood risk maps for the Blue Nile river system in Sudan,
  • Upgrade of the flood forecasting and early warning capability in Sudan (Sudan-FEWS)
  • Establishment of a regional flood seasonal monitoring program and issuance of seasonal forecast (normally 3 months prior to the flood season) and daily forecast during the period July 1stto 21st of each year).
  • Procurements, supply, and delivery of flood surveillance equipment’s targeting pilot flood prone communities such as Singa, Tutti among other
  • Conducted several special studies focusing on the socio-economic and institutional aspects such as Voluntary resettlement studies and the need for institution reforms to enhance the resilience and adaptive capacities in managing flood at regional, national and state

Despite such successful intervention, its sustainability is a major issue and as soon as the project went into closure (2011), its impact at a national level started to recede year by year. Hence there is a need to address the element of sustainability and address the issue of climate change from regional dimension. This could be through strategic shift from projects to continuous program with broaden scope such as disaster management program at a regional level that aimed to address the issue of flood as well as drought. The Disaster Management Program could be hosted by ENTRO and could form the basis for a joint operation and data sharing mechanism of GERD and other dams in the eastern Nile including Roseries, Sennar, Jabel Aulia and High Aswan Dam.

The level of disaster could have been worse if the Nile floods coincided with flash floods due to heavy rainfall, as had happened in 1988 when more than 200 mm of rain occurred within 24 hours. The key attributes to localized flooding problems are the lack of adequate planning with stormwater management and drainage issues completely considered low priority in the design of road network as well as new townships. There is a need for the country to adopt a regulatory framework that honor the natural drainage pattern, prohibit any structures within the natural drainage way and illegalize or prohibit any development or fill within the regulatory floodplain. Also, there is a need at a national level to adopt stormwater management laws and Ordinance that regulate planning and development. This could be supplemented with a drainage manual that guide the development plans and best management practices that could be implemented at the local level to mitigate the impact of localized flooding. This would include green water infrastructures, wetland management, role of detention facilities such as wet and dry ponds and artificial recharge systems. One of the good management practices that could potentially protect people from flooding and safeguard the environment is adoption of zoning ordinance whereby the level of environmental safeguard practices could be thought in a form of Zoning. Areas that are adjacent to floodplains or drainage paths could be mapped as environmental corridor with more restrictions on them.

 Abdin Salih1, Gamal Abdo1, Elfatih Eltahir2, Modathir Zaroug3 and Yosif Ibrahim4

 1 Water Research Centre, Faculty of Engineering, University of Khartoum, Sudan

2 Department of Civil and Environmental Engineering, MIT,  USA.

  • Nile Basin Initiative Secretariat, Entebbe,.
  • Senior Stormwater Engineer, Fairfax Country, Virginia, USA