Overview

Canals have been used since ancient times to carry water where it is needed or allow transportation where natural waterways do not go. The canal lock was developed in China, and first used in Europe during the Middle Ages. Locks enable ships to go from one water level to another, thus making many more transportation routes possible.

Background

Canals are artificial inland waterways. They are built for water supply, sewage removal, crop irrigation, drainage, and transportation. The first known canals were dug in the Middle East thousands of years ago. King Sennacherib, who ruled Assyria in 704-681 B.C., had a 50-mile (80-km) long stone canal built to supply the city of Nineveh with fresh water. Several additional canals were built elsewhere in the Mesopotamian region, as well as in Egypt and Phoenicia. In about 510 B.C. the Persian...