Chapter 16
Potential Transboundary Impacts
of the Grand Ethiopian Renaissance Dam
Under Climate Change and Variability
Khaled M. AbuZeid
Abstract The Blue Nile originates in Ethiopia and flows downstream through Sudan
where it joins the White Nile to form the Main Nile which flows downstream into
Egypt, the most downstream country on the Nile River. The Blue Nile represents
the largest tributary to the Main Nile, providing an average annual flow of about
50 billion cubic meters (BCM), equivalent to about 60% of the natural average
flow of the Main Nile at Aswan in Egypt. Egypt depends on Nile River waters as
its main source of renewable water, utilizing 55.5 BCM annually as per the 1959
agreement which entitles Sudan to 18.5 BCM per year, making Sudan also highly
dependent on the Nile waters. Ethiopia embarked on the construction of the Grand
Ethiopian Renaissance Dam (GERD) on the Blue Nile in 2011, with the announced
objective to generate hydropower. The GERD’s reservoir maximum storage capacity
is 74 BCM and is projected to start filling in 2020, with full operation planned for
2022. The combined effect of the GERD filling and operation, together with the
effect of climate change and variability on the flows of the Blue Nile, calls for
careful assessment of the transboundary implications on downstream. This chapter
presents an assessment of the transboundary impacts of GERD filling and operation
on downstream flows to Sudan and Egypt. Climate variability exacerbates the impacts
of the GERD, especially during years of drought. The analysis was based on 105
historical years of Blue Nile flows, simulation of five different initial water levels of
the High Aswan Dam (HAD) reservoir in Egypt at the start of first filling of the GERD
upstream the Blue Nile, and four different scenarios for annual operation. Modeling
shows that climate change effects, if they materialize with more precipitation, may
naturally mitigate the negative impacts of the GERD on downstream countries so that
they can meet their basic water needs during droughts. In contrast, if climate change
effects materialize with less precipitation this will result in the reduction of flows of
the Blue Nile, and the GERD’s transboundary negative impacts will be exacerbated.
Keywords GERD · Impacts · Nile river · Climate · Transboundary · Renaissance
dam · Blue Nile · Egypt · Sudan · Ethiopia · High Aswan Dam
K. M. AbuZeid (B)
Regional Water Resources Director, Centre for Environment & Development for the Arab Region
(CEDARE), CEDARE, 2 Elhegaz Street, Heliopolis, Cairo, Egypt
e-mail: kabuzeid@cedare.int
© Springer Nature Switzerland AG 2021
S. Diop et al. (eds.), Climate Change and Water Resources in Africa,
https://doi.org/10.1007/978-3-030-61225-2_16
359
Potential Transboundary Impacts
of the Grand Ethiopian Renaissance Dam
Under Climate Change and Variability
Khaled M. AbuZeid
Abstract The Blue Nile originates in Ethiopia and flows downstream through Sudan
where it joins the White Nile to form the Main Nile which flows downstream into
Egypt, the most downstream country on the Nile River. The Blue Nile represents
the largest tributary to the Main Nile, providing an average annual flow of about
50 billion cubic meters (BCM), equivalent to about 60% of the natural average
flow of the Main Nile at Aswan in Egypt. Egypt depends on Nile River waters as
its main source of renewable water, utilizing 55.5 BCM annually as per the 1959
agreement which entitles Sudan to 18.5 BCM per year, making Sudan also highly
dependent on the Nile waters. Ethiopia embarked on the construction of the Grand
Ethiopian Renaissance Dam (GERD) on the Blue Nile in 2011, with the announced
objective to generate hydropower. The GERD’s reservoir maximum storage capacity
is 74 BCM and is projected to start filling in 2020, with full operation planned for
2022. The combined effect of the GERD filling and operation, together with the
effect of climate change and variability on the flows of the Blue Nile, calls for
careful assessment of the transboundary implications on downstream. This chapter
presents an assessment of the transboundary impacts of GERD filling and operation
on downstream flows to Sudan and Egypt. Climate variability exacerbates the impacts
of the GERD, especially during years of drought. The analysis was based on 105
historical years of Blue Nile flows, simulation of five different initial water levels of
the High Aswan Dam (HAD) reservoir in Egypt at the start of first filling of the GERD
upstream the Blue Nile, and four different scenarios for annual operation. Modeling
shows that climate change effects, if they materialize with more precipitation, may
naturally mitigate the negative impacts of the GERD on downstream countries so that
they can meet their basic water needs during droughts. In contrast, if climate change
effects materialize with less precipitation this will result in the reduction of flows of
the Blue Nile, and the GERD’s transboundary negative impacts will be exacerbated.
Keywords GERD · Impacts · Nile river · Climate · Transboundary · Renaissance
dam · Blue Nile · Egypt · Sudan · Ethiopia · High Aswan Dam
K. M. AbuZeid (B)
Regional Water Resources Director, Centre for Environment & Development for the Arab Region
(CEDARE), CEDARE, 2 Elhegaz Street, Heliopolis, Cairo, Egypt
e-mail: kabuzeid@cedare.int
© Springer Nature Switzerland AG 2021
S. Diop et al. (eds.), Climate Change and Water Resources in Africa,
https://doi.org/10.1007/978-3-030-61225-2_16
359