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
Aswan Dam High Dam has resulted in protection from floods and droughts, an increase in agricultural production and employment, electricity production, and improved navigation that also benefits tourism. Conversely, the dam flooded a large area, causing the relocation of over 100,000 people. Many archaeological sites were submerged while others were relocated. The dam is blamed for coastline erosion, soil salinity, and health problems. The assessment of the costs and benefits of the dam remains controversial decades after its completion. According to one estimate, the annual economic benefit of the High Dam immediately after its completion was E£255 million, $587 million using the