(ˈɛi̯səl), sometimes called Gelderse IJssel
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
, 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
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
(itself named after the Vlie strait) and Terschelling
. It is hypothesised that the now-poldered
tidal inlets of Medem
) and IJ
) once were branches of river IJssel.
The IJssel as the lower part of the Oude IJssel
The IJssel was the lower part of the small river Oude IJssel (lit. "Old IJssel", German Issel), 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.
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
streams. The IJssel river is the only branch of the Rhine delta
that takes up tributary rivers rather than giving rise to distributaries.
Only in the last few miles of the river's run, near the city of Kampen, distributaries form, resulting in the relatively minor IJssel delta. Some of the branches have been dammed up to lower the risk of flooding; others have silted up. Several of the delta branches are, however, still connected without interruption. Most of the damming-up was done prior to 1932, when the Zuiderzee was turned into the freshwater IJsselmeer lake. The area had been prone to flooding in times of northwestern gales, pushing back the saline Zuiderzee water into the IJssel delta and preventing the water flowing from the mouths of the IJssel branches from discharging into the Zuiderzee.
The modern-day names of the delta branches are, west to east, Keteldiep, Kattendiep, Noorddiep, Ganzendiep and Goot. Of these, the Keteldiep and Kattendiep channels are the main navigational arteries; the Noorddiep has been closed off at both sides. Another branch, De Garste, had already completely silted up by the middle of the nineteenth century. Until the beginning of the twentieth century, the Ganzendiep branch up to the Goot fork was known as IJssel proper due to it being the historical main channel, with the present-day main channel being called Regtediep or Rechterdiep until well into the twentieth century.
The IJssel, although now technically "merely" a Rhine branch, has retained most of the character of a distinct river in its own right, in no small part due to the fact that it has its own tributaries and, in river Oude IJssel, even a former headstream.
Tributaries and connecting canals
The following canals
streams connect to the IJssel, in downstream order:
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)
Railroad bridges (with nearest train station on the left and right bank):
Only those ferries
capable of carrying motorised vehicles are included.
- Dieren – Olburgen
- Brummen – Bronkhorst
- Welsum – Olst
- Vorchten – Wijhe