Aswan Dam in Egypt had to be dredged regularly to remove sediments. After construction of the dam, aquatic weeds grew much faster in the clearer water, helped by fertilizer residues. The total length of the infested waterways was about 27,000 km in the mid-1990s. Weeds have been gradually brought under control by manual, mechanical and biological methods. Mediterranean fishing and brackish water lake fishery declined after the dam was finished because nutrients that flowed down the Nile to the Mediterranean were trapped behind the dam. For example, the sardine catch off the Egyptian coast declined from 18,000 tons in 1962 to a
Grand Ethiopian Renaissance Dam govern the impacts during the reservoir filling phase include the initial reservoir elevation of the Aswan High Dam, the rainfall that occurs during the filling period and the negotiated arrangement between the three countries. These studies also show that only through close and continuous coordination, the risks of negative impacts can be minimized or eliminated. The reservoir volume (74 billion cubic meters) is about 1.5 times the average annual flow (49 billion cubic meters) of the Blue Nile at the Sudanese-Egyptian border. This loss to downstream countries could be spread over several years if the countries reach an agreement. Depending