River IJssel (), sometimes called Gelderse IJssel ("Gelderland IJssel") to avoid confusion with its Hollandse IJssel namesake in the west of the Netherlands, is a branch of the Rhine in the Dutch provinces of Gelderland and Overijssel. River IJssel flows from Westervoort, east of the city of Arnhem, until it discharges into the IJsselmeer ("Lake IJssel", until the 1932 completion of the Afsluitdijk known as the Zuiderzee, a North Sea inlet). River IJssel is one of the three major distributary branches into which the Rhine divides itself shortly after crossing the German-Dutch border, the other two being the rivers Nederrijn and Waal.

History

The name "IJssel" is thought to derive from the Germanic i sala, meaning "dark water". A branch near its mouth (between Zwolle and Kampen) is today called Zwarte Water, Dutch for "black water". In medieval times, the Zuiderzee had not yet formed from the complex of lakes known as Flevo; the IJssel flowed through these lakes with the last, tidal stretch being called Vlie. Now cut off from the IJssel by means of the Afsluitdijk, Vlie remains as the strait separating the islands of Vlieland (itself named after the Vlie strait) and Terschelling. It is hypothesised that the now-poldered tidal inlets of Medem (near Medemblik) and IJ (near Amsterdam) once were branches of river IJssel.

The IJssel as the lower part of the Oude IJssel

The IJssel once was the lower part of the Oude IJssel (lit. "Old IJssel", German Issel), a small river that rises in Germany and is now a 70 km long tributary of the IJssel. The connection between Rhine and IJssel was probably artificial, allegedly dug by men under the Roman general Nero Claudius Drusus as a defence against Germanic tribes and to let Roman ships carry troops along it. The current Oude IJssel is the second-largest contributor to the flow of the river until today, after river Rhine.

The source of the Oude IJssel is near Borken in North Rhine-Westphalia, Germany. First it flows south-west until it nearly reaches the Rhine near Wesel; then it turns north-west. After passing through Isselburg it crosses the border with the Netherlands. The river, called Oude IJssel from here, then flows through Doetinchem and joins the IJssel at Doesburg.

Characteristics

The average discharge of the IJssel can change significantly. The average discharge has been stated as 300 cubic meters per second. This can be as low as 140 and as high as 1800, depending on the Nederrijn locks west of Arnhem, which regulate the amount of water taken in by the Nederrijn and IJssel branches.

As a lowlands river, the IJssel has a lot of bends and naturally occurring dead branches (locally called "hank"); some bends have been cut off by man (most notably near Rheden and Doesburg), reducing the river's length from 146 km to 125 km, but not nearly as radically as with river Meuse. The naturally occurring phenomenon of sedimental island-forming in the outside of bends has been regulated to the point of non-occurrence since the late nineteenth century.

The IJssel as a Rhine distributary

From the moment the connection between the Rhine and IJssel was dug, the Rhine became the largest contributor to the flow of the IJssel, although only a relatively small amount of the total Rhine flow makes its way into the IJssel system. Various tributaries can sometimes add a considerable volume of water to the total flow of the IJssel, such as the Berkel and Schipbeek streams. The IJssel river is the only branch of the Rhine delta that takes up tributary rivers rather than giving rise to distributaries.

• river Oude IJssel (east) at the city of Doesburg
• the Berkel stream (east) at the city of Zutphen
• the Twentekanaal (east) between Zutphen and the village of Eefde (municipality of Gorssel)
• the Schipbeek stream (east) near the city of Deventer
• the Grift stream (west) at the town of Hattem; its lower reaches have been channelised to form the mouth of the Griftkanaal
• the Willemsvaart canal (east) at the city of Zwolle
• the Zwolle-IJsselkanaal (east) near Zwolle

River crossings

Road bridges

Road bridges across river IJssel (with nearest places on the left and right bank):

• Arnhem - Westervoort
• Arnhem - Duiven (A12 motorway)
• Ellecom - Doesburg (N317)
• Brummen - Zutphen (N314)
• Zutphen - Zutphen
• Wilp - Deventer (A1 motorway)
• Deventer - Deventer (N344)
• Hattem - Zwolle
• Hattemerbroek - Zwolle (A28 motorway)
• Kampen - Kampen (N764)
• Kampen - Kampen
• Kampen - Noordoostpolder (N50)

Ralroad bridges

Railroad bridges (with nearest train station on the left and right bank):

• Arnhem Velperpoort – Duiven
• Brummen/Klarenbeek – Zutphen
• Twello – Deventer
• Wezep – Zwolle

Cable ferries

Only those ferries capable of carrying motorised vehicles are included.

• Dieren – Olburgen
• Brummen – Bronkhorst
• Welsum – Olst
• Vorchten – Wijhe

References