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 average relative humidity of only 26%, with a maximum mean of 42% during winter and a minimum mean of 16% during summer. The weather of Aswan is extremely clear, bright and sunny year-round, in all seasons, with a low seasonal variation, with almost 4,000 hours of annual sunshine, very close to the maximum theoretical sunshine duration. Aswan is one of the sunniest places on Earth. The highest record temperature was on July 4, 1918, and the lowest record temperature was on January 6, 1989. In 1999, South Valley University was inaugurated and it has three branches; Aswan, Qena and Hurghada.