A summit-level canal, sometimes called a "watershed canal" or just "summit Canal", is an artificial waterway connecting two separate river valleys. The term refers to a canal that rises to cross a summit then falls down the other side. Typically, summit-level canals include a summit pound, a level stretch of water at the highest part of the canal, usually contained by locks that prevent the water from flowing downstream in either direction. Since water flows out when locks open to admit boats, the summit pound must have a water supply. By contrast, a ''lateral canal'' has a continuous fall only.

History

The first canal to connect rivers across a watershed was the

Lingqu Canal The Lingqu () is a canal in Xing'an County, near Guilin, in the northwestern corner of Guangxi, China. It connects the Xiang River (which flows north into the Yangtze) with the Li River (Guangxi), Li River (which flows south into the Gui ...

("Magic Canal") in China which connected the Xiang and Li rivers for military transport. Construction began in 223 BCE and the canal was in use by 214 BCE. [Needham, Joseph and Wang Ling ''Science and Civilisation in China'', Part 3 “Civil Engineering and Nautics” of Volume IV “Physics and Physical Technology” (Cambridge University Press, Cambridge, 1971) Library of Congress Card Number 54-4723 pp 299 & ff ] The Lingqu carried boats and barges over a 30-meter high summit at an elevation of 210 meters, connecting the Yangtze River watershed with the Pearl River watershed. The Lingqu facilitated the unification and creation of China under its first emperor Qin Shi Huangdi. A second Chinese summit-level canal was the Grand Canal of China.The International Canals Monuments List
This was started in the 4th century BCE with major extensions in 329 CE, But it was the rerouting of the canal in the 1280s to shorten the connection to the new capital

Beijing Beijing, Chinese postal romanization, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's List of national capitals by population, most populous national capital city as well as ...

at the start of the

Yuan dynasty The Yuan dynasty ( ; zh, c=元朝, p=Yuáncháo), officially the Great Yuan (; Mongolian language, Mongolian: , , literally 'Great Yuan State'), was a Mongol-led imperial dynasty of China and a successor state to the Mongol Empire after Div ...

, crossing the Yangtze and

Yellow River The Yellow River, also known as Huanghe, is the second-longest river in China and the List of rivers by length, sixth-longest river system on Earth, with an estimated length of and a Drainage basin, watershed of . Beginning in the Bayan H ...

s, that established it as a summit-level canal. It remained into the modern era as the longest canal in the world at . In Europe, the first summit-level canal was the Stecknitz Canal (1390–1398) in Germany which connected the Stecknitz river to the Delvenau, a tributary of the Elbe, as part of the Old Salt Route. It used fifteen staunches and had a summit level; the millers only opened the flash locks on alternate days. The first summit canal to use pound locks was the Briare Canal in France which was completed in 1642. This canal connected the

Loire The Loire ( , , ; ; ; ; ) is the longest river in France and the 171st longest in the world. With a length of , it drains , more than a fifth of France's land, while its average discharge is only half that of the Rhône. It rises in the so ...

valley to that of the

Seine The Seine ( , ) is a river in northern France. Its drainage basin is in the Paris Basin (a geological relative lowland) covering most of northern France. It rises at Source-Seine, northwest of Dijon in northeastern France in the Langres plat ...

to carry the agricultural produce of the Loire to Paris. In many ways it is the ancestor of all modern summit-level canals being fed from its reservoir, Étang de la Gazonne. One of the greatest engineering feat of the 17th century was the Canal du Midi in Southern France opened in 1684, joining the Garonne, which drains into the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

to the Étang de Thau which leads to the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

. Its length rises at the western end and falls to the east via 103 locks, one tunnel and three major aqueducts. To solve the water supply problem, the engineer Pierre-Paul Riquet constructed a major dam in the Black Mountains and constructed a feeder canal approximately long. A large network of 18th- and 19th-cantury summit-level canals in England, France, and other European countries facilitated the Industrial revolution.

List of major summit-level canals by continent

Asia

;China * Grand Canal *

Europe

France * Canal de Briare * Canal du Midi * Canal du Rhône au Rhin * Canal du Centre * Canal de l'Oise à l'Aisne Germany * Rhine-Main-Danube Canal * Kiel Canal England * Trent and Mersey Canal * Leeds and Liverpool Canal * Grand Union Canal * Kennet and Avon Canal * Rochdale Canal * Huddersfield Narrow Canal *

Oxford Canal The Oxford Canal is a narrowboat canal in southern central England linking the City of Oxford with the Coventry Canal at Hawkesbury (just north of Coventry and south of Bedworth) via Banbury and Rugby. Completed in 1790, it connects to th ...

Northern Ireland * Newry Canal Scotland * Caledonian Canal * Crinan Canal * Forth and Clyde Canal Poland * Augustów Canal Russia * White Sea – Baltic Canal * Volga–Baltic Waterway Sweden * Göta Canal

North America

United States * Chesapeake and Delaware Canal *

Erie Canal The Erie Canal is a historic canal in upstate New York that runs east–west between the Hudson River and Lake Erie. Completed in 1825, the canal was the first navigability, navigable waterway connecting the Atlantic Ocean to the Great Lakes, ...

* Morris Canal Canada * Rideau Canal Panama *

Panama Canal The Panama Canal () is an artificial waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a Channel (geography), conduit for maritime trade between th ...

References