Eritrea's Coastal Marine and Island Biodiversity Conservation Project

1.6. The Sea (Definition and Bathymetry)
The marine environment of Eritrea extends from the mean low water level, derived from the mean of lower tide in reference to the last 11 to 12 years
readings. Human activities start from the highest water level, but its position is expected to change over the years (sea level rise, exceptional natural
events).
Countries are usually setting a distance from the highest water level for coastal protection, infrastructure, military or customs activities. This zone is
named the setback. In Eritrea, following technical meetings for the preparation of the Coastal Policy, a horizontal distance of 100m from a datum
(geological or biological) is the accepted but not yet formally adopted standard.
According to the International Law of the Sea, Eritrea’s territorial waters extend to 12 nautical miles (about 22 km) from the mean low water line of
the coastline of the mainland and of the islands. The total area of the Eritrean territorial waters is therefore estimated to be 55,000 km².
The maximum extension of the Exclusive Economic Zone (EEZ) is 200 nautical miles but is reduced to the median line between two countries’
territorial waters. The area of the EEZ (including the territorial waters) is estimated to be 120,000 km².
1.7. Coastal Erosion, Climate Change, Sea Level Rise and Setback Datum
Natural coast is subject to changes due to sedimentation or erosion. The nature of the coast, rocky or sandy, is important in planning and implementing
development activities. Rocky coast is stable but sandy coasts changes with the movements of the sea and the input of sediment, reduced in Eritrea due
to the lack of permanent rivers.
Low lying and sandy areas are at risk from erosion, in particular from eventual sea level rise, specific events such as equinox tides, low barometric
pressure, strong wind and waves during storms or in relation with climatic changes over a longer period of time. For the impact of climate change,
scientific forecasts indicate a rise of about 50 cm in the coming century with the possibility of being higher in specific areas. The impact of such sea
level rise will be different on different coastal areas subject to the nature of the coast, rocky or sandy and elevation level.
A coastal setback is a horizontal distance along the coastline (mainland and islands) defined on the basis of coastal morphology, exposure, stability of
the coastline, nature of coastal resources, nature of the activity and other relevant criteria. In Eritrea, the setback distance meant to protect development
investments such as roads, industries or tourism facilities by absorbing the impact of severe storms, by allowing the shoreline movement, the global sea
level rise and the fluctuation of natural coastal processes.
State of the Coast Eritrea, 2006-2007 6