Construction on the Grand Ethiopian Renaissance Dam (GERD)
– Africa’s biggest hydropower dam – began based on piecemeal
preliminary studies and design documents, with only a very basic
analysis of how the project would affect downstream neighbors, according
to the 2013 final report by an international panel of experts
established to evaluate the scheme. The megadam is being built on the
Blue Nile in Ethiopia, near the Sudan border, and has created conflict
with Egypt over its downstream impacts; the experts' study confirms
Egypt’s concerns that the project’s impacts could be significant and are
not well understood.
The Ethiopian government reported last year
that the panel’s report “showed that the Dam offers high benefit for
all the three countries and would not cause significant harm on both the
lower riparian countries”, while Egypt has repeatedly said the report calls for more analysis of downstream impacts.
Because the report was not made public, neither side could be vetted.
Egypt has called for mediation if further studies are not allowed; at
this writing, Ethiopia had refused, and was continuing with dam
construction.In March 2014, International Rivers received a leaked copy of the report. The report documents numerous problems with existing analysis and a lack of analysis on a number of critical issues. The panel recommends further investigation into the dam’s hydrological impacts, including on downstream countries’ water supplies and power generation; risks from climate change, and geotechnical issues. The panel recommends “a full transboundary environmental and social impact assessment … conducted jointly by the three countries.”
The 10-member panel included two members from each of the three riparians (Egypt, Ethiopia and Sudan), plus four international experts agreed upon by the governments. A geotechnical expert group was added later. The main panel met for about a year, and had four field visits to the dam site. While the panel's members were granted access to many key project documents (all of which remain confidential at this time), some key reports were not shared with them, including the critical geotechnical assessments for the main and saddle dams, and project cost-benefit analyses.
One international dam expert who has seen the report states that it shows that construction on the project is proceeding on “an aggressively accelerated schedule” with little room for adjusting key elements of dam design to reduce harm or prevent problems. A number of key studies for the project are described by the panel as being outdated or in process. While references are made to some specific international standards being adhered to, overall, the process described seems chaotic and incomplete. It is also clear that there is precious little oversight on Africa’s largest dam project to date. While the international panel has brought a type of oversight, it may be too little, too late – and with too little teeth; it seems the panel does not have a continuing role in ensuring best practices as construction proceeds.
The panel’s report is almost a year old at this writing, yet its members have been mostly silent since their report was completed (as far as we know, none of the panelists have made public statements about the project). The Egyptian and Ethiopian governments continue the war of words, while at the same time construction on the megadam proceeds, and questions raised by the panel remain unanswered.
Going forward, International Rivers recommends construction on the project be halted
until all necessary studies recommended by the panel are completed, and
a process is in place for ensuring public accountability on the
project. Given the panel's findings, Egypt’s call for mediation in the
process is reasonable, and donor governments and international bodies
should support such a process.
The following summarizes some of the panel’s key findings and recommendations: - Quality of project documents: The present design criteria are “quite general, and do not include project- and site-specific conditions … The most essential geotechnical, seismological, hydro-geological, hydrological, hydraulic and structural design data should be compiled into a consolidated report and not scattered in numerous design reports.” The project’s main design report is outdated and does not reflect numerous and significant design changes to the project.
- Safety: “The stability of the main dam and other main structures should be verified under consideration of additional geological and geotechnical findings.” The panel believes more analysis may be necessary, but without having access to all information on this aspect of the project, cannot be sure. Nonetheless, they do question some assumptions on the project’s “shear strength” and raise concerns about sliding, seepage and other safety issues. “In view of the on-going construction works . . . highest priority shall be given to clarify [dam safety issues] as soon as possible. Structural measures might be needed to stabilize the foundation to achieve the required safety against sliding.” The panel also suggests design modifications for the saddle dam and further studies on the spillway dimensions. The panel recommends that the discharge of the “Probable Maximum Flood” used in the dam design be increased.
- Downstream changes to water flow: First and foremost, “The (hydrological study) is very basic, and not yet at a level of detail, sophistication and reliability that would befit a development of this magnitude, importance and with such regional impact as GERD.” Project studies looked only at the GERD site. “No upstream developments are taken into account, and no downstream flow records … are given as would be needed to assess downstream impacts.” The panel notes that, “given the proposed upstream cascade development of similar magnitude than the GERD, the upstream flow records could be of significant importance.” The panel notes that the hydrological report uses questionable estimates of evaporation from the reservoir (a key issue in how much water the dam will “use”), and recommends further assessments of evaporation. It also notes that the project did not quantify water losses through deep percolation during reservoir filling. Regarding GERD's impact on Egypt's water supply, the panel found that “mass balances represented in the report of water between the GERD and the High Aswan Dam could not be reconciled given the information presented.” The GERD also allows for greater expansion of irrigated cropping in Sudan, which could further reduce flows to Egypt; the panel recommends a detailed study on this issue.
- Environmental impacts: Surprisingly little information is included on impacts on local people, ecosystems, fisheries or biodiversity. The official Environmental and Social Impact Assessment Report was “strictly limited to the impact zones located upstream of the dam site in Ethiopia.” Downstream environmental impacts were not considered as being significant, and therefore several related socio-economic impacts are not addressed. Dam height was chosen without consideration of downstream environmental and socio-economic impacts. The panel recommends a full transboundary impact assessment be done.
- Climate risks: The panel notes that the project did not assess the project’s sensitivity to climate change. A project of this scale and with such heavy reliance on rainfall patterns requires a better understanding of future hydrologic conditions to ensure the highest degree of flexibility and resiliency in its design and operation. The panel recommends a study that looks at the potential influence of climate change on the flow regime at GERD and further downstream.
- Sediment and water quality issues: The project did not include an analysis of sediment deposition in the reservoir (a troublesome issue for dams on the muddy Nile). The panel notes that sediment flows downstream of the dam will be substantially reduced, with implications for floodplain farming productivity, navigation, Sudan’s brick industry, riverbank erosion, and biodiversity. The panel also recommends additional studies on water quality changes from the project, particularly on methane gas production and the depletion of dissolved oxygen levels in water releases that could harm fisheries and biodiversity downstream.
- Dam operations: Very little information on how the dam will be operated was given. At a basic level, both present and future needs for “peaking power versus base power needs to be assessed in more detail,” and “needs to be taken into account in (project) planning and sizing.” The report requests verification of the 6,000MW installed capacity. Furthermore, the Panel does not indicate if the dam was designed in a way to accommodate “environmental flows” (which can be used to mitigate impacts of a dam on a river). In all likelihood this was not considered as the panel writes that "it is not clear whether the present design considers (capacity, functionality) the minimum mean flows of the dry months release to the downstream countries” without use of power generation facilities or the spillway. It is also clear that consideration of operation of the GERD in coordination with water systems in Egypt and Sudan was at a very preliminary stage during the writing of this report. The report strongly recommends additional studies of the GERD “in the context of the Eastern Nile System” in order to “quantify the downstream impacts in detail with confidence.”
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