Rhine

The Rhine is a long river in Europe.

It starts as two little streams high in the snowy mountains of Switzerland. It flows past old castles, big cities and green vineyards. Big boats carry things up and down it. At the end, it reaches the sea.

The Rhine is one of Europe's great rivers. It starts high in the Alps of Switzerland, flows through Lake Constance and over the Rhine Falls, then runs north between France and Germany, through Germany, and out to the North Sea through the Netherlands. For a while it also forms the border between Switzerland and Liechtenstein and between Switzerland and Austria.

Its length was long given as 1,320 kilometers, but in 2010 a shorter figure of about 1,230 kilometers was proposed. The International Commission for the Protection of the Rhine says about 60 million people live in its basin, in nine countries. The name Rhine probably comes from an old Celtic word meaning great running water.

Britannica describes the Rhine as culturally and historically one of the great rivers of Europe and among the most important arteries of industrial transport in the world. It flows from two headstreams in east-central Switzerland north and west to the North Sea through the Netherlands. Its length was long given as 1,320 km; in 2010 a shorter figure of about 1,230 km was proposed. It is navigable for some 870 km, up to Rheinfelden on the Swiss-German border, and Britannica gives a catchment of more than 220,000 km² including the delta.

The International Commission for the Protection of the Rhine (ICPR) counts about 60 million people in the watershed, across nine states, and calls it the most important cultural and economic axis in Middle Europe. The ICPR also explains that the name is probably Celtic, meaning great running water, which the Romans kept as Rhenus. Below Basel the river forms the French-German border as far as the Lauter, then flows through Germany to Emmerich, below which its many-branched delta shapes the Dutch landscape.

The Rhine starts as two small streams in the mountains.

They join and flow into a big lake. Then the river crashes over a wide waterfall. It runs through a deep, rocky valley. At the end, it splits into many arms and reaches the sea.

The Rhine's two headstreams rise high in the Swiss Alps. The Vorderrhein flows out of Lake Toma, 2,344 meters above sea level, and joins the Hinterrhein near the city of Chur. The young river then flows into Lake Constance, where its current slows and it builds a small delta.

Leaving the lake, it pours over the Rhine Falls at Schaffhausen and runs west to Basel. There it turns north across a flat valley about 30 kilometers wide. Between Bingen and Bonn, the river has cut a deep, winding gorge between steep, slaty hills, the most famous stretch of the river. Below the German border town of Emmerich, in the Netherlands, it splits into wide branches such as the Lek and the Waal before reaching the sea.

The Vorderrhein emerges from Lake Toma at 2,344 m near the Oberalp Pass and is joined by the Hinterrhein at Reichenau above Chur. The Alpine Rhine, with a steep gradient and a typical Alpine regime of winter lows and spring and early-summer highs, builds a delta where it enters Lake Constance; that flat-floored stretch has been straightened and its banks reinforced. Below the lake, the High Rhine passes the Rhine Falls, entirely in Swiss territory, and receives the Aare, which on average carries more water than the Rhine itself. The ICPR notes the river kept the name Rhine because its course to the confluence is longer.

Below Basel the river crosses a flat-floored valley some 20 miles (about 30 km) wide between the Vosges and Black Forest; until straightening began in the early 19th century it looped across its floodplain in great meanders, whose cutoffs survive near Breisach and Karlsruhe. The middle Rhine has cut a deep, winding gorge 145 km long between the slate-covered Hunsrück and Taunus. Below Bonn the valley opens into a plain, and below Emmerich the delta branches into the Lek, Waal and Merwede. Since the Delta Project was completed in 1986, all main branches are closed off and water reaches the sea through sluices and side channels.

Long ago, salmon swam up the Rhine from the sea.

Then the river got dirty, and dams blocked the way. People worked hard to clean the water. Now some salmon are swimming back up the Rhine!

Salmon live most of their lives in the sea but swim back up rivers to lay their eggs, following the smell of their home water. Once, the Rhine had no obstacles from the North Sea all the way up to the Rhine Falls, so salmon could swim into streams in the Alps and the Black Forest.

Then weirs, dams and pollution cut the salmon off from their old spawning streams. In 1986 a fire at a chemical warehouse near Basel poured pesticides into the Rhine, turned it red and killed huge numbers of fish. After that, the countries along the river worked together to clean it. Since 1990, salmon have been swimming back up from the North Sea, and since 1994 they have laid eggs naturally in the Sieg, a tributary.

The ICPR explains the life cycles that make the Rhine a migratory-fish river. Salmon grow in the sea and return to spawn, guided by the smell of their home waters (homing); most make the exhausting journey only once. European eels do the reverse: they grow in rivers and return to spawn in the Sargasso Sea; their larvae reach Europe's coasts after about three years, and females mature after 12 to 15 years. Naturally, the Rhine was free of obstacles from the North Sea to the Rhine Falls.

River training, weirs and hydropower plants on the Upper Rhine and its tributaries, and the Haringvliet sluices in the delta, broke this continuity. On 1 November 1986 a fire at the Sandoz site in Schweizerhalle near Basel released some 20 to 30 tons of pesticides and other chemicals (Britannica's figure), causing mass fish deaths. The Rhine Action Programme and Salmon 2000 followed: salmon have migrated upstream since 1990 and reproduced naturally in the Sieg since 1994, the first large fish pass on an Upper Rhine barrage opened at Iffezheim in 2000, and the old Rhine's fish fauna was almost complete again at 63 species, only the sturgeon missing. In 2020 the Rhine ministers adopted Rhine 2040 and confirmed the aim of restoring continuity up to the Rhine Falls.