View source for Weser

{{short description|River in Germany}}
{{Other uses}}
{{More citations needed|date=March 2021}}
{{Infobox river
| name               = Weser
| name_other         = Werser ([[Low German]])
| name_etymology     = ''*waisōn'', [[Proto-Germanic language|Proto-Germanic]], meaning "flow" or "ooze"
| image              = Weser2.JPG
| image_size         = 300
| image_caption      = The Weser near Bad Oeynhausen
| map                = Weser Einzugsgebiet.png
| map_caption        = Watershed of the Weser
| pushpin_map        = Germany
| pushpin_map_size   = 
| pushpin_map_caption = European context: mouth within Germany.
| mapframe           = yes
| mapframe-zoom      = 5
| subdivision_type1  = Country
| subdivision_name1  = [[Germany]]
| subdivision_type2  = [[States of Germany|States]]
| subdivision_name2  = {{hlist|[[Bremen (state)|Bremen]]|[[Lower Saxony]]|[[North Rhine-Westphalia]]|[[Thuringia]]|[[Hesse]]}}
| subdivision_type5  = Cities
| subdivision_name5  = {{hlist|[[Bremerhaven]]|[[Bremen]]|[[Minden]]|[[Hamelin]]|[[Hann. Münden]]|[[Kassel]]|[[Fulda (river)|Fulda]]}}
| length             = {{convert|452|km|mi|abbr=on}} [{{convert|744|km|mi|abbr=on}} if combined with the Werra]
| width_min          = 
| width_avg          = 
| width_max          = 
| depth_min          = 
| depth_avg          = 
| depth_max          = 
| discharge1_location= 
| discharge1_min     = 
| discharge1_avg     = {{convert|327|m3/s|cuft/s|abbr=on}}
| discharge1_max     = 
| source1            = 
| source1_location   = Confluence of the [[Fulda (river)|Fulda]] and [[Werra]] Rivers in [[Hann. Münden]]
| source1_coordinates= {{coord|51|25|17|N|9|38|53|E|display=inline}}
| source1_elevation  = {{convert|116|m|abbr=on}}
| mouth              = [[Wadden Sea]] of the [[North Sea]]
| mouth_location     = Between [[Bremerhaven]] and [[Nordenham]]
| mouth_coordinates  = {{coord|53|32|8|N|8|33|56|E|display=inline,title}}
| mouth_elevation    = {{convert|0|m|abbr=on}}
| river_system       = Weser basin
| basin_size         = {{convert|46306|km2|abbr=on}}
| tributaries_left   = [[Diemel]], [[Emmer]], [[Werre]], [[Große Aue]], [[Hunte]]
| tributaries_right  = [[Aller (Germany)|Aller]], [[Lesum]]
| extra = 
}}
[[File:Orthographic projection centred over Bremen and the Weser watershed.png|thumb|50px]]

The '''Weser''' ({{IPA|de|ˈveːzɐ|pron|de-Weser.ogg}}) is the second longest river in [[Germany]]. Weser flows from the [[Thuringian Forest]] to the [[North Sea]], where it flows into the sea near [[Bremerhaven]].

The Weser begins at [[Hann. Münden|Hannoversch Münden]] through the [[confluence]] of the [[Werra]] and [[Fulda (river)|Fulda]]. It passes through the [[Hanseatic League|Hanseatic]] city of [[Bremen]]. Its mouth is {{convert|50|km|mi|abbr=on}} further north against the ports of [[Bremerhaven]] and [[Nordenham]]. The latter is on the [[Butjadingen|Butjadingen Peninsula]]. It then merges into the [[North Sea]] via two highly [[Saline water|saline]], [[Estuary|estuarine]] mouths.

It connects to the canal network running east–west across the [[North German Plain]].

The river, when combined with the '''Werra''' (a dialectal form of ''Weser''),<ref>Vgl. [[Hans Krahe]]: ''Unsere ältesten Flußnamen'', Wiesbaden 1964, Pages&nbsp;101 and 24.</ref> is {{convert|744|km|mi|abbr=on}} long and thus, the longest river entirely situated within Germany (the [[Main (river)|Main]], however, is the longest if the Weser-Werra are considered separate). The Weser itself is {{convert|452|km|mi|abbr=on}} long. The Werra rises in [[Thuringia]], the [[States of Germany|German state]] south of the main projection (tongue) of Lower Saxony.

==Etymology==
"Weser" and "Werra" are the same words in different dialects. The difference reflects the old [[isogloss|linguistic border]] between [[Central German|Central]] and [[Low German]], passing through Hannoversch Münden.

The name likely derives from the Old Germanic {{lang|gem-x-proto|*waisōn}} "flow, ooze".<ref>{{Cite book |last=Orel |first=Vladimir |url=https://archive.org/stream/Orel-AHandbookOfGermanicEtymology/2003OrelV.-AHandbookOfGermanicEtymology#page/n479/mode/1up |title=A Handbook of Germanic Etymology |publisher=Koninklijke Brill NV |year=2003 |isbn=9789004128750 |location=Netherlands |pages=441 |language=en |author-link=Vladimir Orel}}</ref>{{failed verification|date=December 2024|reason=Orel doesn't mention the Weser in his entry for *waisōn}} It is cognate with the [[River Wear|Wear]] in England and [[Vistula]] (Polish Wisła, German Weichsel) in Poland, all of which are derived from the [[Proto-Indo-European language|Proto-Indo-European]] root {{wikt-lang|ine-x-proto|*weys-}} "to flow", which also gives rise to Old English/Old Frisian {{lang|ang|wāse}} "mud, ooze", Old Norse {{lang|non|veisa}} "slime, stagnant pool", Dutch {{lang|nl|waas}} "haze; soggy land" (see [[Waasland]]), Old Saxon {{lang|osx|waso}} "wet ground, mire", Old High German {{lang|goh|wasal}} "rain", and French {{lang|fr|vase}} "mud, sludge".

==Course==
The Weser starts at the confluence of the Fulda and the Werra. It then runs down to the [[Porta Westfalica (gorge)|Porta Westfalica]] between two high hill ranges, the [[Wiehengebirge|⁣⁣Wiehengebirge⁣⁣]] in the west and the [[Weserbergland]] in the east.

Between [[Minden]] and the North Sea, humans have [[river engineering|largely canalised the river]] up to a limit of 1,200-ton ships. Eight hydroelectric dams stand at the ends of adjacent weir weirstreams that make up the river. The navigation is linked west to the [[Dortmund–Ems Canal]] via the [[Coastal Canal]]. It is linked east at [[Bremerhaven]] to the [[Elbe River|Elbe]].

A large reservoir, the [[Edersee]], on the [[Eder (Fulda)|Eder]], the main tributary of the Fulda, is used to allow enough water depth for shipping year-round. The dam, built in 1914, was [[Operation Chastise|bombed and severely damaged by British aircraft]] in May 1943, causing great destruction and about 70 deaths downstream. It was rebuilt within four months. The reservoir is a major summer resort area. Turbines driven by its [[hydroelectricity|sluices provide electricity]].
[[File:AlteWeser 1964.jpg|thumb|upright|[[Alte Weser Lighthouse]]]]
<gallery widths="180" heights="135">
Weserradweg b Oedelsheim.jpg|"Upper" Weser, in reality the central section between the upper courses Werra and Fulda, and the lowland section
Minden Weser-Mittelland Kanal Lock 01.jpg|[[Mittelland Canal]]/River Weser Lock in Minden taken in 1977
MI-16 River Weser (Minden) North (RLH).jpg|View north of the River Weser and the road bridge at Minden
River Weser (Minden) South To Porta West Falica (RLH).jpg|Southern view of the River Weser from the road bridge at Minden in 1977
</gallery>

The Weser enters the North Sea in the southernmost part of the [[German Bight]]. In the sea it splits into two arms &ndash;the riverbed at the end of the [[Quaternary glaciation|last ice age]]. These sea arms are called ''Alte Weser'' (old Weser) and ''Neue Weser'' (new Weser). They are the waterways for ships heading for the ports of [[Bremerhaven]], [[Nordenham]], and [[Bremen (city)|Bremen]]. The [[Alte Weser Lighthouse]] marks the northernmost point of the Weser. This replaced the [[Roter Sand Lighthouse]] in 1964.

== Weser deepening ==
Since the 19th century, the Weser has been deepened twelve times by humans. This caused severe ecological damage to the river.

With each deepening, the tides were altered by the faster inflow of North Sea tides. This increases the risk of flooding along the river.<ref>{{Cite web |title=Login - DVZ |url=https://www.dvz.de/login.html?redirect_url=https%3A%2F%2Fwww.dvz.de%2Funternehmen%2Fsee%2Fdetail%2Fnews%2Fumweltverbaende-kein-bedarf-fuer-vertiefung-der-aussenweser.html |access-date=2025-07-01 |website=www.dvz.de}}</ref>

==Tributaries==
The largest tributary of the Weser is the [[Aller (Germany)|Aller]], which joins south of Bremen. Tributaries of the Weser and the Werra (from source to mouth) are:

'''Modes of the list:'''
* Listed upstream, but sides seen with the flow
* Distances ("km …") from the hydrographical limit towards the sea
** "II", "III"and "IV" mark distances of secondary/tertiary tributaries from the confluence with the Weser etc.
* After the names, lengths and basin sizes are given.
* Lengths with longer affluents are given behind the slash lengths including an upper course with another name with "or"
[[File:Weser basin topo.png|thumb|509px|Weser and its tributaries in blue, other rivers in grey]]
'''List:'''
* km 19, right: [[Geeste (river)|Geeste]] (in Bremerhaven), 42.5&nbsp;km, 338&nbsp;km<sup>2</sup>
* km 33, right: [[Lune (Weser)|Lune]], 43&nbsp;km, 383&nbsp;km<sup>2</sup>
* km 35.9, right: [[Drepte]], 37.6&nbsp;km, 101&nbsp;km<sup>2</sup>
* km 52.8, left: [[Hunte]], 189&nbsp;km, 2.785&nbsp;km<sup>2</sup>
** II: km 125.7: Lake [[Dümmer]]
* km 67.6, right: [[Lesum]], 9.9 or 131.5, 2,188&nbsp;km<sup>2</sup>
** II: km 9.9, right [[Hamme (river)|Hamme]], 48.5&nbsp;km, 549&nbsp;km<sup>2</sup>
**↑ main stream: [[Wümme]], 118 / 120, 1,585&nbsp;km<sup>2</sup>
* km 72.5, left: [[Ochtum]], 25.6 or 45&nbsp;km, 917&nbsp;km<sup>2</sup>
** II: km 25.6: left [[Hache (Ochtum)|Hache]], 33&nbsp;km, 118&nbsp;km<sup>2</sup>
* km 125.6, right: [[Aller (Germany)|Aller]], 260&nbsp;km, 15,744&nbsp;km<sup>2</sup>
** II: km 63.6, left: [[Leine]], 278&nbsp;km, 5,617&nbsp;km<sup>2</sup>, stronger than river Aller above
*** III: km 112.7, right: [[Innerste]], 99.7&nbsp;km, 1,264&nbsp;km<sup>2</sup>
*** III: km 192.8, right: [[Rhume]], 44&nbsp;km, 1,193&nbsp;km<sup>2</sup>, stronger than river Leine above
*** IV: km 15.6, right: [[Oder (Harz)|Oder]], 56&nbsp;km, 385&nbsp;km<sup>2</sup>, headwater of the strongest waterway of Aller system
** II: km 97.3, right: [[Örtze]], 62 / 70&nbsp;km, 760&nbsp;km<sup>2</sup>
** II: km 140.7, left: [[Oker]], 218&nbsp;km, 1822&nbsp;km<sup>2</sup>, stronger than river Aller above
* km 184.6, right: Steinhuder Meerbach
** ↑ km II: 29 lake [[Steinhuder Meer]]
* km 188.7, left: [[Große Aue]], 84.5&nbsp;km, 1,522&nbsp;km<sup>2</sup>
* km 261.3, left: [[Werre]], 71.9&nbsp;km, 1485&nbsp;km<sup>2</sup>
** II: km 12.7, left: [[Else (Werre)|Else]], 34.6&nbsp;km, 416&nbsp;km<sup>2</sup>, branch of the [[Hase]], an affluent of [[Ems (river)|Ems]]
* km 287.7, left: [[Exter (Weser)|Exter]], 26.1&nbsp;km, 109&nbsp;km<sup>2</sup>
* km 323.3, left: [[Emmer (Weser)|Emmer]], 61.8&nbsp;km, 535&nbsp;km<sup>2</sup>
* km 387.5, left: [[Nethe]], 50.4&nbsp;km, 460&nbsp;km<sup>2</sup>
* km 406.5, left: [[Diemel]], 110.5&nbsp;km, 1,762&nbsp;km<sup>2</sup>
* km 451.5, left: [[Fulda (river)|Fulda]], 220.4&nbsp;km, 6.947&nbsp;km<sup>2</sup>
:: II: km 45.3, left: [[Eder (Fulda)|Eder]], 176.1&nbsp;km, 3,361 km<sup>2</sup>, headwater of the strongest waterway of Weser system
::: III: km 17.1, left: [[Schwalm (Eder)|Schwalm]], 97.1&nbsp;km, 1.299 km<sup>2</sup>
::: ↑ III: km 49.4–70.5: [[Edersee]] reservoir
:: II: 120.1, right: [[Haune]], 66.5&nbsp;km, 500 km<sup>2</sup>
* ↑ main stream above km 451.5: [[Werra]], 299.6&nbsp;km, 5.497&nbsp;km<sup>2</sup>
* km 566.5, right: [[Hörsel]], 55.2 or 64.3, 784&nbsp;km<sup>2</sup>
** km 9.8, right: [[Nesse (Hörsel)|Nesse]], 54.5&nbsp;km, 426&nbsp;km<sup>2</sup>
* km 513.1, left: [[Ulster River|Ulster]], 57.2&nbsp;km, 421&nbsp;km<sup>2</sup>
* km 604.4, right: [[Schleuse (river)|Schleuse]], 34.2&nbsp;km, 283&nbsp;km<sup>2</sup>

==Notable towns==
Main towns along the Weser are (from the head of the river to its mouth): [[Hann. Münden]], [[Beverungen]], [[Hoexter|Höxter]], [[Holzminden]], [[Bodenwerder]], [[Hamelin]], [[Hessisch Oldendorf]], [[Rinteln]], [[Vlotho]], [[Bad Oeynhausen]], [[Porta Westfalica]], [[Minden]], [[Petershagen]], [[Nienburg, Lower Saxony|Nienburg]], [[Achim]], [[Bremen]], [[Brake (Unterweser)|Brake]], [[Nordenham]], and [[Bremerhaven]].

==Popular culture==
The river features in the legend and folk tale the [[Pied Piper of Hamelin]].

== References ==
{{Reflist}}

===Etymology===
* Dieter Berger: ''Geographische Namen in Deutschland''. Duden-Verlag, Mannheim 1999.
* Hans Krahe: ''Sprache und Vorzeit''. Quelle & Meyer, Heidelberg 1954. (''Zur alteuropäischen Hydronomie''.)
* Julius Pokorny: ''Indogermanisches etymologisches Wörterbuch''. Francke, Bern 1959.

=== Geology ===
* Karsten Meinke: ''Die Entwicklung der Weser im Nordwestdeutschen Flachland während des jüngeren Pleistozäns''. Diss., Göttingen 1992. Mit Bodenprofilen der Weserstädte.
* Ludger Feldmann und Klaus-Dieter Meyer (Hrsg.): ''Quartär in Niedersachsen. Exkursionsführer zur Jubiläums-Hauptversammlung der Deutschen Quartärvereinigung in Hannover''. DEUQUA-Exkursionsführer, Hannover 1998, page 89ff.
* Hans Heinrich Seedorf und Hans-Heinrich Meyer: ''Landeskunde Niedersachsen. Natur und Kulturgeschichte eines Bundeslandes''. Volume 1: ''Historische Grundlagen und naturräumliche Ausstattung''. Wachtholz, Neumünster 1992, page 105ff.
* Ludger Feldmann: ''Das Quartär zwischen Harz und Allertal mit einem Beitrag zur Landschaftsgeschichte im Tertiär''. Papierflieger, Clausthal-Zellerfeld 2002, page 133ff and others.

=== Archaeology ===
* Bremer Archäologische Blätter, Beiheft 2/2000 zur gleichnamigen Ausstellung im Focke-Museum: ''Siedler, Söldner und Piraten, Chauken und Sachsen im Bremer Raum'',  Der Landesarchäologe Bremen, {{ISSN|0068-0907}}.
* Bremer Archäologische Blätter, Beiheft 3/2004 zur gleichnamigen Ausstellung im Focke-Museum: ''Gefundene Vergangenheit'', Archäologie des Mittelalters in Bremen,  Der Landesarchäologe Bremen, {{ISBN|3-7749-3233-6}}. (wg.Geschichte des [[Balge (Arm der Weser)|Weserarms Balge]])

=== History ===
* Georg Bessell: ''Geschichte Bremerhavens''. Morisse, Bremerhaven 1927, 1989.
* Heinz Conradis: ''Der Kampf um die Weservertiefung in alter Zeit''. In: ''Bremisches Jahrbuch''. Bremen 41.1944.
* J. W. A. Hunichs: ''Practische Anleitung zum Deich-, Siel- und Schlengenbau''. Erster Theil, von den Sielen. Bremen 1770.
* ''Die Kanalisierung der Mittelweser''. Published by the Mittelweser AG, Carl Schünemann Verlag, Bremen 1960.
* Kuratorium für Forschung im Küsteningenieurswesen: ''Die Küste''. In: ''Archiv für Forschung und Technik an der Nord- und Ostsee''. Boyens, Heide 51.1991. {{ISSN|0452-7739}}

=== Description ===
{{NIE Poster}}
* Karl Löbe: ''Das Weserbuch''. Niemeyer, Hameln 1968.
* Nils Aschenbeck, Wolf Dietmar Stock: ''Eine Flussfahrt von der Aller bis zur Nordsee''. Atelier im Bauernhaus, Fischerhude 1998. {{ISBN|3-88132-350-3}}.

{{Rivers of Germany}}

{{Authority control}}

[[Category:Weser| ]]
[[Category:Weser basin| ]]
[[Category:Rivers of Lower Saxony]]
[[Category:Rivers of Bremen (state)]]
[[Category:Bodies of water of the North Sea]]
[[Category:Federal waterways in Germany]]
[[Category:Rivers of Germany]]
[[Category:Pied Piper of Hamelin]]