A river monitoring station functioned in Wadi Halfa between 1911 and 1931, to monitor changes associated with the Aswan reservoir, but from 1931 to 1962 it was moved to Kajnarty, 47 kilometres to the north of the town. A railroad hotel was built in the town during the 20th century, and during World War II, Wadi Halfa was a communications post for Allied forces in Africa. By 1956, the town had grown to a population of 11,000. On 8 November 1959, the signing of the Sudanese-UAR Nile Water Agreement brought the area into much debate, given that the agreement to flood the area upon the creation of the Aswan Dam would directly affect some 52,000 people in the area who would have to be resettled over a four-year period from 1960. Worst affected were the Nubians who demonstrated in Wadi Halfa on 23–24 October 1960 against being resettled, and on 26 October demonstrations took place in the Sudanese capital, Khartoum, which had to be dispersed by police using tear gas. The government was quick to suppress the agitation, placing Wadi Halfa under martial law and terminating communications with the rest of the country. Protests in Khartoum, mainly by students, led to the temporary closure of the Khartoum campus of Cairo University and about 50 arrests. The old town was completely destroyed after the construction of the Aswan High Dam due to flooding in 1964. Most of the town was relocated, and by 1965 the population of New Halfa was just 3,200. During the 1970s, the area was under intense scrutiny by archaeologists working to protect ancient Nubian monuments.