XOCHIMILCO

delegacin (administrative subdivision), central Federal District, central Mexico. It lies at 7,461 feet (2,274 metres) above sea level in the Valley of Mexico, on Lake Xochimilco. The name Xochimilco is a combination of the Nahuatl words xochitl and milli and means where the flowers grow. Built on the site of a pre-Columbian town, Xochimilco is famous for its chinampas, or floating gardens. The local agriculturalists constructed branch and reed rafts on the lake, covered them with mud from the bottom of the lake, and cultivated fruits, vegetables, and flowers, which they shipped to Tenochtitlan (now Mexico City) via canal. In time the rafts took root and became islands. Xochimilco is a popular weekend outing for thousands of Mexicans and tourists, who visit the area in colourful flat-bottomed boats (trajineras). It is still an important market-gardening and flower-producing centre for the city, despite its being surrounded by urban sprawl in the latter part of the 20th century. Downtown Mexico City, 14 miles (23 km) to the north-northwest, can be reached via an expressway link or by several major avenues. A campus of the Autonomous Metropolitan University is located in Xochimilco. In 1987 Xochimilco was designated a World Heritage site. The growth of Mexico City has had serious detrimental effects on the canals and chinampas. In 1993 Mexico City initiated a program that improved treatment of municipal sewage in order to reverse the deterioration of the site. Pop. (1980) 217,481; (1990 prelim.) 271,020.