A boat cannot go forward if each rows his own way

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8 TNDam safety:Coordinated operationof transboundarycascade damsInfographic: Nile BasinInitiative (NBI) / GunnarBauerRISKSClimateextremesDamfailuresUncoordinatedoperation+ Extreme floods+ Prolonged droughts+ Loss of lives, properties& services+ Regional insecurity+ Environmental damage+ Energy underproduction+ High & low releases+ Inefficiency of irrigation water use+ Evaporation lossACTION BENEFITSAdaptionstrategies+ Strengthen forecasting system+ Drought & flood managementplansFlood & droughtcontrol+ Reliable water supply+ Resilient economiesDam safetystandards+ Institutional & legal framework+ Setting construction, operation& safety standardsFunctionalsafety+ Safety of downstream lives,property & environment+ Regional security+ Sustained economic servicesRegionalcooperation+ Regional optimised planning+ Setting up basin organisation+ Standardise toolsMaximisedreturns+ Energy uplift+ Irrigation expansion+ Improved navigation+ Sustained environmental flowTN15_20210310.indd 8 2021/03/10 18:29
Do damsMiCT The NilesBerlin, GermanyTN 9causemoreproblemsthantheysolve?All across the Nile Basin, damsgenerate power, store drinkingand irrigation water, as well asprevent flooding and create spacesto relax. On the downside, dams,especially poorly maintained structures,can endanger local people,especially in the context of a rapidlychanging climate.Adam is a barrier or structure which blocks astream, river, water-way to confine and controlthe flow of water.Dams are classified according tothe materials from which they are built.Embankment dams, for example, caneither be earth-filled or rock-filled. The damcontains more than 50 percent of either soiland gravel-sized or smaller rocks (earth-filled)or cobble-sized or larger rocks (rock-filled).This type of dams represents about75 percent of all of the dams in the world.Concrete dams, on the other hand, are mainlyconstructed from cast-in-place or roller-compactedconcrete. Composite dams are composedof both, with concrete gravity or buttresssection in combination with earth-filled orrock-filled embankment sections.Earth filled dams were constructed asfar back as 2000 BC. Built from 276 to 303AD, and restored in 1901, the Minneriyadam in Sri Lanka is the oldest still in use.Today there are over 60,000 largedams in operation. A large dam, accordingto the International Commission on LargeDams (ICOLD), has a height of over 15 metresor is both between 10 and 15 metres high andhas a storage capacity of over 3 million cubicmetres (MCM).A typical swimming pool (25 m x 10 mwith an average depth of 1.5 m) would havea volume of 375 cubic metres. For context,3 MCM is equivalent to 8,000 of such swimmingpools.In comparison, the Grand EthiopianRenaissance Dam (GERD) is planned to havea reservoir with a volume of more than 74billion cubic metres, or more than 197 milliontypical swimming pools.The Eastern Nile damsThe Eastern Nile Sub-basin is hometo several large and complex dams, withother dams under construction and in theplanning phase.At present, the Eastern Nile countrieshost more than 30 large dams with a combinedtotal storage capacity of more than 200billion cubic metres (BCM) (>25 percent ofexisting African dams’ storage capacity). It isalso estimated that more than 300 small damsexist in the Eastern Nile countries.These dams hold several risks, but, ifthese are overcome, the structures can benefitall eastern Nile Basin countries.Climate variability“More than 90 percent of the world’srivers will be fragmented by at least one damwithin the next 15 years” according to a studyby researchers at the University of Waterlooand the Université libre de Bruxelles.The same study investigates the impactsof dams and reservoirs on the earth’s climate,as they “trap nearly one-fifth of the organiccarbon moving from land to ocean via theworld’s rivers”.“In similar recent studies, the groupof researchers also found that ongoing damconstruction impedes the transport of nutrientssuch as phosphorus, nitrogen andsilicon through river networks. The changesin nutrient flow have global impacts onthe quality of water delivered to wetlands,lakes, floodplains and coastal marine areasdownstream.”The impact of dams on climate hasalso been documented, but it is essentialto remember that humans can also decidehow much they want to influence the environmentthrough building dams. Dams arebuilt to be used for irrigation, water supply,energy, or flood control.Dams can also be multipurpose and beused for two or more of the above purposes.They can also mitigate the effect of floods“90 percentof the world’srivers willbe fragmentedby at leastone dam.”or droughts, thus contributing towards localcommunities becoming more resilient.Within the Nile Basin, the High AswanDam is an excellent example that demonstratesboth positive and negative impacts.On the one hand, its consequences include“an explosion of water hyacinth, outbreaksof bilharzia [an infection caused by a parasiticworm that lives in fresh water], pollutedirrigation channels and a build-up of sedimentinland that would otherwise compensatefor coastal erosion from Egypt to Lebanon,”TN15_20210310.indd 9 2021/03/10 18:29
Page 1 and 2: “A boatcannotgo forwardif eachrow
Page 3 and 4: The damTN 3conundrum:To buildor not
Page 5 and 6: The cascade effect:TN 5sharing info
Page 7: TN 7A photojournalist fromEgypt at
Page 11 and 12: EL-QANATER EL-KHAYREYA DAM, EgyptEx
Page 13 and 14: Can South Sudan relaunchTN 13its Fu
Page 15 and 16: TN 15THE KHASHM EL-GIRBA DAMTHE ROS
Page 17 and 18: TN 17obviously have a major effect
Page 19 and 20: TN 19resettlement, saying that that
Page 21 and 22: TN 21kilometres in length, with a s
Page 23 and 24: Dagim TerefeAddis Ababa, EthiopiaCh
Page 25 and 26: Farming is not the only source of i
Page 27 and 28: The Grand EthiopianRenaissance Dam

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