Most of the first Dams were built in Mesopotamia up to 7,000 years ago. These were used to control the water level, for Mesopotamia's weather affected the Tigris and Euphrates rivers, and could be quite unpredictable. The earliest recorded dam is believed to have been on the Sadd Al-Kafara at Wadi Al-Garawi, which is located about 25 kilometers south of Cairo, and built around 2600 B.C. It was destroyed by heavy rain shortly afterwards. The oldest surviving and standing dam in the world is believed to be the Grand Anicut, also known as the Kallanai, an ancient dam built on the Kaveri River in the state of Tamil Nadu located in southern India. It was built by the Chola king Karikalan, and dates back to the 2nd century AD. Du Jiang Yan in China is the oldest surviving irrigation system included a dam that direct waterflow. It was finished in 251 B.C. The Kallanai is a massive dam of unhewn stone, over 300 meters long, 4.5 meters high and 20 meters (60 feet) wide, across the main stream of the Kaveri. The purpose of the dam was to divert the waters of the Cauvery across the fertile Delta region for irrigation via canals. The dam is still in excellent repair, and served as a model for later engineers, including the Sir Arthur Cotton's 19th-century dam across the Kollidam, the major tributary of the Cauvery. The land area irrigated by the ancient irrigation network, of which the dam was the centerpiece, was 69,000 acres (280 square kilometers). By the early 20th century the irrigated area had been increased to about 1,000,000 acres (4,000 square kilometers ). In ancient China, the Prime Minister of Chu (state), Sunshu Ao, is the first known hydraulic engineer of China. He served Duke Zhuang of Chu during the reign of King Ding of Zhou (606 BC-586 BC), ruler of the Eastern Zhou Dynasty. His large earthen dam flooded a valley in modern-day northern Anhui province that created an enormous irrigation reservoir (62 miles in circumference), a reservoir that is still present today. In the Netherlands, a low-lying country, dams were often applied to block rivers in order to regulate the water level and to prevent the sea from entering the marsh lands. Such dams often marked the beginning of a town or city because it was easy to cross the river at such a place, and often gave rise to the respective place's names in Dutch. For instance the Dutch capital Amsterdam (old name Amstelredam) started with a dam through the river Amstel in the late 12th century, and Rotterdam started with a dam through the river Rotte, a minor tributary of the Nieuwe Maas. The central square of Amsterdam, believed to be the original place of the 800 year old dam, still carries the name Dam Square or simply the Dam.
History of Dams
The word dam can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities.