The Rhine–Main–Danube Canal ( German: ''Rhein-Main-Donau-Kanal''; also called Main-Danube Canal, RMD Canal or Europa Canal), is a

canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface ...

Bavaria Bavaria, officially the Free State of Bavaria, is a States of Germany, state in the southeast of Germany. With an area of , it is the list of German states by area, largest German state by land area, comprising approximately 1/5 of the total l ...

, Germany. Connecting the Main and the

Danube The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...

rivers across the European Watershed, it runs from

Bamberg Bamberg (, , ; East Franconian German, East Franconian: ''Bambärch'') is a town in Upper Franconia district in Bavaria, Germany, on the river Regnitz close to its confluence with the river Main (river), Main. Bamberg had 79,000 inhabitants in ...

via

Nuremberg Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...

to Kelheim. The canal connects the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

and

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

Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...

, providing a navigable artery between the

Rhine The Rhine ( ) is one of the List of rivers of Europe, major rivers in Europe. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps. It forms part of the Swiss-Liechtenstein border, then part of the Austria–Swit ...

delta (at

Rotterdam Rotterdam ( , ; ; ) is the second-largest List of cities in the Netherlands by province, city in the Netherlands after the national capital of Amsterdam. It is in the Provinces of the Netherlands, province of South Holland, part of the North S ...

in the Netherlands), and the

Danube Delta The Danube Delta (, ; , ) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. Occurring where the Danube, Danube River empties into the Black Sea, most of the Danube Delta lies in Romania ...

in south-eastern

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

and south-western

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

(or

Constanța Constanța (, , ) is a city in the Dobruja Historical regions of Romania, historical region of Romania. A port city, it is the capital of Constanța County and the country's Cities in Romania, fourth largest city and principal port on the Black ...

, through the Danube–Black Sea Canal). The present canal was completed in 1992 and is long.

Early history

Projects for connecting the Danube and Rhine basins by canal have a long history. In 793, the Emperor

Charlemagne Charlemagne ( ; 2 April 748 – 28 January 814) was List of Frankish kings, King of the Franks from 768, List of kings of the Lombards, King of the Lombards from 774, and Holy Roman Emperor, Emperor of what is now known as the Carolingian ...

ordered the construction of a canal—the '' Fossa Carolina'' (German: ''Karlsgraben'')—connecting the Swabian Rezat, a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

of the Rednitz, to the Altmühl near

Treuchtlingen Treuchtlingen () is a town in the Weißenburg-Gunzenhausen district, in Bavaria, Germany. It has a population of around 12,000. History The spot where the town is situated was first settled by Celts, Roman Empire, Romans and Franks. The town prope ...

. Between 1836 and 1846 the

Ludwig Canal The Ludwig Canal (German: Ludwig-Donau-Main-Kanal or Ludwigskanal), is an abandoned canal in Southern Germany. History The canal linked the Danube, Danube River at Kelheim with the Main (river), Main River at Bamberg, connecting the Danube b ...

(German: Ludwigskanal), named for King Ludwig I of Bavaria, was built between Bamberg and Kelheim. This canal had a narrow channel, with many locks, and a shortage of water in the peak section, so the operation of the waterway soon became uneconomic—especially given the rapidly advancing construction of the

railway Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

network in the southern German countryside. The canal finally was abandoned in 1950, after a decision was made to not repair damage it had suffered from Allied bombing during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. In 1917, the Landtag of Bavaria passed a law calling for the development of a major shipping route "between Aschaffenburg and

Passau Passau (; ) is a city in Lower Bavaria, Germany. It is also known as the ("City of Three Rivers"), as the river Danube is joined by the Inn (river), Inn from the south and the Ilz from the north. Passau's population is about 50,000, of whom ...

", with the capacity to carry the 1,200-ton ships used on the

. On 13 June 1921, Bavaria and the German Reich concluded an agreement to build the "''Main-Donau-Wasserstraße''". Under this plan, in addition to the expansion of the Main and Danube, a completely new channel linking the rivers was to be created. The Rhein-Main-Donau AG (RMD-AG) was founded on 30 December 1921 to undertake the project. To finance the waterway, the RMD was given control of the water resources of the Main, Danube, Lech, Altmühl, and Regnitz.

Construction

The first concrete plans for the new waterway emerged in 1938, for the so-called Mindorfer Linie south of Nuremberg. As early as 1939 the first preparatory work began at Thalmässing in Landkreis Roth. However, after the war this route was dropped. By 1962, the Main's channel had been expanded as far upstream as Bamberg. In 1966, the Duisburger Vertrag, an agreement between Bavaria and the Federal Republic of Germany, was reached for financing the completion of the project. The contract was signed on 16 September of that year in

Duisburg Duisburg (; , ) is a city in the Ruhr metropolitan area of the western States of Germany, German state of North Rhine-Westphalia. Lying on the confluence of the Rhine (Lower Rhine) and the Ruhr (river), Ruhr rivers in the center of the Rhine-Ruh ...

by Federal Transport Minister Hans-Christoph Seebohm, Federal Finance Minister Rolf Dahlgrün, Bavarian Prime Minister Alfons Goppel and the Bavarian Finance Minister Konrad Pöhner. The last section to be built, between Nuremberg and Kelheim, became politically controversial in the 1970s and 1980s, mainly because of the long section through the Altmühl valley. On 25 September 1992, the canal was completed. The equivalent of some 2.3 billion

euro The euro (currency symbol, symbol: euro sign, €; ISO 4217, currency code: EUR) is the official currency of 20 of the Member state of the European Union, member states of the European Union. This group of states is officially known as the ...

s were invested in the construction from 1960 to 1992. Almost 20 percent of that went for environmental protection projects.

Route

From Bamberg to Fürth the canal follows the valley of the Regnitz, a tributary of the Main. From Fürth to beyond Roth it follows the valley of the Rednitz, a tributary of the Regnitz. It crosses the Franconian Jura mountains and joins the river Altmühl near

Dietfurt Dietfurt an der Altmühl (officially Dietfurt a.d. Altmühl, , ), commonly known as Dietfurt, is a Town#Germany, town in the Neumarkt (district), district of Neumarkt in Bavaria, Germany. The town is situated on the river Altmühl, and is 38 ...

. From Dietfurt to Kelheim on the Danube the canal follows the Altmühl valley.

The remnants of the Ludwig Canal

Today, some 60 kilometers of the

still exists in good condition between

and Berching. Some of the locks still function, and part of the towpath has been converted to a cycle track. The old canal comes close to the new canal at Pollanten, and from there the two canals flow downstream in parallel, eventually meeting 5km south of Berching.

Dimensions

The cross-section of the waterway is normally trapezoidal, with width at the bottom, width at the water surface, of water depth, and a side grade of 1:3. The channel is a Waterway Class Vb; the largest authorised vessel is long and wide. The channel in the Kelheim-bound Bamberg lock has a depth of . In the few sections with a rectangular profile, the width is usually (i.e., the mean between top and bottom widths). The length of the canal is ; the summit elevation (between the Hilpoltstein and Bachhausen locks) is above

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

. This is the highest point on Earth that is currently reached by commercial watercraft from the sea. The height difference along the north ramp of the canal—from the Main at

to the crest elevation—is , with 11 locks. From the crest elevation down to the Altmühl at

is a drop of through three locks. The further difference in elevation of along the Altmühl, with two more locks, makes a total of for the south ramp. This means that the Danube end of the canal is above the level of the Main end.

Locks

Along the course of the canal there are 16 locks with lifting heights of up to 25 meters (). The 16 locks are managed from four remote control centres (Neuses since 2007, Kriegenbrunn, Hilpoltstein, and Dietfurt from the beginning of 2007). These centres are staffed with one worker on the night shift, and two on the day shift. The locks were modernized from 2001 to 2007, replacing the outdated relay technology with programmable logic controllers (PLC). The cost was approximately $1.3 million per lock. The summit pound is maintained by pumping water from the canal stretches below; and some water is drained into the summit pound from local natural sources. Finally a pumped storage artificial lake ''Dürrlohsee'' that sits even higher in elevation than the summit pound makes up the difference if the aforementioned sources of water are not sufficient. Thirteen locks are designed to conserve water, which they do by piping first the top third, and then the middle third of the lock water into side tanks during the down cycle. On the up cycle, these tanks replenish first the bottom third and then the middle third of the lock volume. The remaining top third is supplied by water from the upper level of the canal.

Commercial operation

There were different forecasts of freight transport volumes, from which benefit–cost ratio could be derived. In 1981, a Federal Minister for Transport cost–benefit account assumed an estimated traffic volume of only 2.7 million tonnes per year for the Main-Danube Canal, and a benefit–cost ratio of 0.52:1. This might have justified the termination of the project. One of the proponents commissioned a study by the Ifo-Institut München, predicting an estimated 5.5 million tonnes per year for the traffic volume on the Main-Danube Canal. In 2004, the freight volume in exchange traffic totalled 5.9 million tonnes and the total transport 6.9 million tonnes. The course of the planned extension of the Danube

waterway A waterway is any Navigability, navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other ways. A first distinction is ...

between

and Kelheim is still controversial. Proponents argue that the cost structure of inland navigation will require larger ship sizes, so that larger lock dimensions, deeper channels and secure minimum water depth will be required. Opponents argue the

environmental degradation Environment most often refers to: __NOTOC__ * Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism ...

is too great and that inland navigation is falling.

Transport volumes

Transport volumes for 2006

The transport volume through the RMD Canal in 2006 was down almost 20% compared to the previous year. * Total 6.24 million

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...

s (2005: 7.598 million tonnes) * Number of vessels 5,280 (6,467), of which 2,823 travelled in the direction of the Danube and 2,457 toward the Rhine * The channel was closed due to ice at Nuremberg for 25 days for traffic in the direction of the Main, and for 37 days in the direction of the Danube. The most important goods, which were transported on the canal toward the Danube: * Food and feed: 836,186 tonnes * Ores and scrap: 795,259 tonnes *

Iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

, non-ferrous metals: 103,547 tonnes * Stones, soil, building rubble: 510,187 tonnes * Fertilizers: 296,340 tonnes Goods transported toward the Rhine * Food and feed: 476,422 tonnes * Iron, steel, non-ferrous metals: 419,459 tonnes * Fertilizers: 295,701 tonnes. The container traffic declined from 3,986 to 2,539 TEUs. Of these 85% were in the direction of Danube. Meanwhile,

tourism Tourism is travel for pleasure, and the Commerce, commercial activity of providing and supporting such travel. World Tourism Organization, UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as ...

along the canal is economically important. This has contributed to the extensive creation of habitats to compensate for the canal.

Transport volumes 2010

The transport volume in traffic between Main-Danube Canal and Danube (Kelheim lock) in 2010 consisted of the following items (in tons):Wasser- und Schifffahrtsdirektion Süd
Verkehrsbericht 2010
raffic report August 2011. Freight volume by country between Main-Donau-Kanal and Donau (Kelheim Lock) in 2010:

Impact on ecology

The construction of canals involves ecological dangers. The Main-Danube Canal makes it possible for

aquatic animal An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in a body of water for all or most of its lifetime. Aquatic animals generally conduct gas exchange in water by extracting dissolved oxygen via specialised respirato ...

s to spread from Western to

Eastern Europe Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural and socio-economic connotations. Its eastern boundary is marked by the Ural Mountain ...

and ''vice versa''.

Invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

often cause adverse impacts in the

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

of new habitats:

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

with

native species In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...

, lack of natural predators, introduction of diseases and

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s, etc. However, there is also the possibility that they will naturalize into the new ecosystem and their introduction lead to an enrichment of the resident

wildlife Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introdu ...

. In order to maintain navigable water levels for the waterway in the Main, Regnitz and Rednitz valleys, water must be diverted via the Altmühlüberleiter canal & tunnel from the upper Altmühl to the Brombachsee reservoirs, across the European Watershed between the

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

s of the Danube and Rhine. On the other hand, the canal carries

cargo In transportation, cargo refers to goods transported by land, water or air, while freight refers to its conveyance. In economics, freight refers to goods transported at a freight rate for commercial gain. The term cargo is also used in cas ...

traffic that would otherwise require 250,000 truck trips annually, or as an alternative, 3,000 freight trains on the Deutsche Bahn rail network.

Invasive animal species, east to west

So far about 20 species of

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s and a number of

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

have spread from the Danube to the Main, and on to the Rhine and Lake Constance. The following list shows some examples:
Aquatische Neozoen im Bodensee
'' auf: ''neozoen-bodensee.de'', Stand 29. November 2011. * Fish ** Topmouth gudgeon (''Pseudorasbora parva'') ** Zarte (''Vimba vimba'') ** White-eye bream ('' Abramis sapa'') ** Western tubenose goby (''Proterorhinus semilunaris'') ** Asp (''Aspius aspius'') * Amphipods ** '' Dikerogammarus villosus'' ** '' Corophium curvispinum''

Invasive animal species, west to east

This exchange also works in the opposite direction. Examples include: * Asian clam (''Corbicula fluminea'') * the freshwater shrimp ('' Atyaephyra desmaresti''). * the Chinese mitten crab (''Eriocheir sinensis'') (was found in the Austrian Danube in November 2002 for the first time).

1979 damburst at Katzwang

The construction work was interrupted on 26 March 1979 by a serious accident in the Nuremberg district of Katzwang. A dam broke on the Eibach– Schwanstetten section, which was still under construction but already flooded. About of waterZeittafel
imeline Wasserstraßen- und Schifffahrtsamt Nürnberg poured through the wide hole and flooded large parts of old Katzwang. The force of the water was so great that it dug a wide crater and swept away cars, people and houses. During the rescue operations, a 12-year-old girl died. The damage was around DM 24 million (converted c. 12 million

s). After the disaster, the entire canal line was checked for weaknesses and retrofitted at critical points.

Triathlon

The long-distance Challenge Roth

triathlon A triathlon is an endurance multisport race consisting of Swimming (sport), swimming, Cycle sport, cycling, and running over various distances. Triathletes compete for fastest overall completion time, racing each segment sequentially with the ...

, which is held annually in July, includes a swim in the Main-Danube Canal at Hilpoltstein. The canal is closed to vessel traffic during the race. An approximately -long section of the marathon route runs along the canal from the Hilpoltstein lock to the Leerstetten lock.

Notes

External links

Structurae: Main-Danube Canal

hips travel over the mountains
Der Neue Kanal: Main-Donau-Kanal

istory of the Main-Danube Canalby Wilhelm Doni
RMD Wasserstraßen GmbH

Wasserstraßen- und Schifffahrtsamt Nürnberg

Bibliography on Water Resources and International Law
Peace Palace Library {{DEFAULTSORT:Rhine-Main-Danube Canal International canals Ship canals Canals in Germany Danube Federal waterways in Germany Canals opened in 1992 CRhineMainDanube CRhineMainDanube