View source for Shinano River

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{{EngvarB|date=June 2019}}
{{Use dmy dates|date=June 2019}}
{{Infobox river
| name               = Shinano River
| name_native        = 信濃川
| name_native_lang   = 
| name_other         = Chikuma River (千曲川)
| name_etymology     = 
<!---------------------- IMAGE & MAP -->
| image              = Shinano river.JPG
| image_size         = 
| image_caption      = The Shinano River in Niigata just before it flows into the Sea of Japan
| map                = 
{{Maplink|zoom=7|frame=yes|plain=yes|frame-align=right|frame-width=280|frame-height=500|frame-latitude=36.93|frame-longitude=138.88
|type=shape|stroke-color=#0000ff|stroke-width=1|id=Q734455
|type2=shape|stroke-color2=#0000ff|stroke-width2=1|id2=Q61041464
|type3=line|stroke-color3=#0000ff|stroke-width3=2|id3=Q61041464
}}
| map_size           = 
| map_caption        = 
| pushpin_map        = 
| pushpin_map_size   = 
| pushpin_map_caption= 
<!---------------------- LOCATION -->
| subdivision_type1  = Country
| subdivision_name1  = [[Japan]]
| subdivision_type2  = Prefectures
| subdivision_name2  = [[Nagano Prefecture|Nagano]], [[Niigata Prefecture|Niigata]]
| subdivision_type3  = 
| subdivision_name3  = 
| subdivision_type4  = 
| subdivision_name4  = 
| subdivision_type5  = Cities
| subdivision_name5  = [[Niigata, Niigata|Niigata]], [[Nagaoka, Niigata|Nagaoka]], [[Nagano (city)|Nagano]], [[Matsumoto, Nagano|Matsumoto]]
<!---------------------- PHYSICAL CHARACTERISTICS -->
| length             = {{convert|367|km|mi|abbr=on}} 
| width_min          = 
| width_avg          = 
| width_max          = 
| depth_min          = 
| depth_avg          = 
| depth_max          = 
| discharge1_location= [[Ojiya, Niigata|Ojiya]]
| discharge1_min     = {{convert|91|m3/s|cuft/s|abbr=on}}
| discharge1_avg     = {{convert|503|m3/s|cuft/s|abbr=on}}
| discharge1_max     = {{convert|3776|m3/s|cuft/s|abbr=on}}
<!---------------------- BASIN FEATURES -->
| source1            = Mount Kobushigatake
| source1_location   = [[Japanese Alps]], [[Nagano Prefecture]]
| source1_coordinates= {{coord|35.913|138.7194}}
| source1_elevation  = {{convert|2475|m|abbr=on}}
| mouth              = [[Sea of Japan]]
| mouth_location     = [[Niigata Prefecture]]
| mouth_coordinates  = 
| mouth_elevation    = {{convert|0|m|abbr=on}}
| progression        = 
| river_system       = 
| basin_size         = {{convert|11900|km2|abbr=on}}
| tributaries_left   = Urano River, Sai River (Nagano)
| tributaries_right  = Yu River (Nagano), Hoshina River, Ayu River, Yagisawa River, Matsu River, [[Uono River]]
| custom_label       = 
| custom_data        = 
| extra              = <ref name="KyotoUni"/><ref name="MLIT-basin"/>
}}

The {{nihongo|'''Shinano River'''|信濃川|Shinano-gawa}}, known as the {{Nihongo|'''Chikuma River'''|千曲川|Chikuma-gawa}} in its upper reaches, is the longest and widest river in Japan and the third largest by basin area (behind the [[Tone River]] and [[Ishikari River]]). It is located in northeastern [[Honshu]], rising in the [[Japanese Alps]] and flowing generally northeast through [[Nagano Prefecture|Nagano]] and [[Niigata Prefecture|Niigata]] Prefectures before emptying into the [[Sea of Japan]].<ref name="MLIT-basin">{{cite web|author=Shinanogawa River Office|title=The Shinano River Basin|url=http://www.hrr.mlit.go.jp/shinano/english/basin/basin.html|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref><ref name="Nilsson">{{cite journal|last1=Nilsson|first1=Christer|last2=Reidy|first2=Catherine|last3=Dynesius|first3=Mats|last4=Revenga|first4=Carmen|title=Fragmentation and Flow Regulation of the World's Large River Systems|journal=Science|date=15 April 2005|volume=308|issue=5720|pages=405–408|doi=10.1126/science.1107887|url=http://science.sciencemag.org/content/308/5720/405|accessdate=3 July 2017|bibcode=2005Sci...308..405N}}</ref><ref name="WorldAtlas">{{cite web|last1=Sawe|first1=Benjamin Elisha|title=Longest Rivers in Japan|url=http://www.worldatlas.com/articles/the-longest-rivers-in-japan.html|website=WorldAtlas|accessdate=3 July 2017|language=en|date=17 March 2017}}</ref>

==History==
The Shinano River has a long history in Honshu, and along with other rivers in the region, has a significant effect on the geography and ecology of the area. Originally the Shinano River would have drained straight into an estuary-like Fukushima lagoon<ref name="Goldsmith2008"/>{{rp|41}} before making its way into the Sea of Japan after flowing down from the Japanese Alps. Over centuries of sediments being brought downstream, a marshy plain formed in the lagoon into what is currently the Echigo Plain.<ref name="MLIT-history">{{cite web|author=Shinanogawa River Office|title=History|url=http://www.hrr.mlit.go.jp/shinano/english/weir/history.html|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref><ref name="Cambridge">{{cite web|title=Shinano River Project|url=http://www.arch.cam.ac.uk/research/projects/shinano-river|website=Division of Archaeology|publisher=[[University of Cambridge]]|accessdate=3 July 2017|language=en}}</ref> Estimates presented in 1993 place the amount of loose sediment in the river system at {{convert|400|-|500|m3/km}}.<ref name="Cheng2014">{{cite book|last1=Cheng|first1=Liang|last2=Draper|first2=Scott|last3=An|first3=Hongwei|title=Scour and Erosion: Proceedings of the 7th International Conference on Scour and Erosion, Perth, Australia, 2–4 December 2014|date=2014|publisher=CRC Press|isbn=9781315723594|pages=170–172|url=https://books.google.com.au/books?id=lVDvBQAAQBAJ|accessdate=6 July 2017|language=en}}</ref> The construction of diversion channels have limited the upkeep required to keep a navigable passage between the Niigata port and the open ocean;<ref name="Shibayama2009">{{cite book|last1=Shibayama|first1=Tomoya|title=Coastal Processes: Concepts in Coastal Engineering and Their Applications to Multifarious Environments|date=2009|publisher=World Scientific|isbn=9789812813954|page=766|url=https://books.google.com.au/books?id=Xlem_qwlSfwC|accessdate=6 July 2017|language=en}}</ref> however, a consequence of diverting sediment has been that the northern coast of Niigata Prefecture (which includes [[Niigata, Niigata|Niigata]] and its port) is receding by an average {{convert|9|m3/m}} per year (measured from 1947 to 1975) due to sediment being released well-south of the river's original mouth in Niigata.<ref name="Goda2010">{{cite book|last1=Goda|first1=Yoshimi|title=Random Seas and Design of Maritime Structures|date=2010|publisher=World Scientific|isbn=9789814282390|page=612|url=https://books.google.com.au/books?id=v_unn4FtFXsC|accessdate=6 July 2017|language=en}}</ref>

[[File:Jomon Vessel with Flame-like Ornamentation, attributed provenance Umataka, Nagaoka-shi, Niigata, Jomon period, 3000-2000 BC - Tokyo National Museum - DSC05620.JPG|thumb|150px|left|Flame-style pottery from the Nagaoka site]]
The Shinano River Project, funded by the [[British Academy]], investigates the development of the Shinano—Chikuma River system. It has uncovered some of the earliest examples of Flame-style pottery (kaen doki), dating from the [[Jōmon period#Middle Jōmon (2500–1500 BCE)|Middle Jōmon period]] (3500–2500 [[BCE]]), have been found at Sanka excavation site in [[Nagaoka City|Nagaoka, Niigata]], near the confluence of the Sai and Shinano Rivers.<ref name="Cambridge"/><ref name="Sainsbury">{{cite web|title=Shinano-Chikuma River Project|url=http://sainsbury-institute.org/research/archaeology-and-heritage/shinano-chikuma-river-project-2/|website=[[Sainsbury Institute for Art|Sainsbury Institute for the Study of Japanese Arts and Cultures]]|publisher=[[University of East Anglia]]|accessdate=8 July 2017}}</ref>

As with rivers across the world, the Shinano provided a valuable means of transport. The system also provided a method of transport for goods to be moved downstream to one of three ports, Nutaru, Niigata and the provincial port of Kambara. Little evidence remains which details the importance or role of these ports; however, large amounts of Medieval Chinese artefacts have been found in the region and it is the setting of the [[Muromachi period]] play, ''Miuri'', was set in Kambara indicating its regional significance.<ref name="Goldsmith2008"/>{{rp|37–38}} There is limited evidence which has caused some historians (such as Shishi Tokamachi) to suggest that the Shinano system was not widely used for boat travel until the eighteenth century.<ref name="Goldsmith2008"/>{{rp|41}} Brian Goldsmith, however, contends that the Shinano was, in fact, used for waterborne trade based on archaeological finds, including coin hoards and imported pottery, found in the headwaters of the Shinano.<ref name="Goldsmith2008"/>{{rp|41–43}} One of the main inland roads in Honshu followed the Shinano valley inland <!-- inland through Nagano and onto the Tosan highway in --> to the Japanese Alps. The location of the road indicates that the river played a vital role in local trade. The Chikuma valley also provided a link across the island of Honshu.<ref name="Goldsmith2008">{{cite book|last1=Goldsmith|first1=Brian|title=Amassing economies: The medieval origins of early modern Japan, 1450–1700|date=2008|publisher=Stanford University|url=http://pqdtopen.proquest.com/doc/304469078.html?FMT=ABS|accessdate=4 July 2017}}</ref>{{rp|32,50}}

The confluence of the Chikuma and Sai rivers, called the Kawanakajima Plain, was the location a [[Battles of Kawanakajima|series of battles]] in the sixteenth century as part of the [[Sengoku period]]. The most significant of the battles was fought on 18 October 1561 between the [[Takeda clan]] and [[Uesugi clan]], and resulted in severe casualties to both sides.<ref name="Turnbull2000">{{cite book|last1=Turnbull|first1=Stephen|title=The samurai sourcebook|date=2000|publisher=Cassell|location=London|isbn=1854095234|edition=Reprinted}}</ref> The battles have become well known in Japanese military history, mentioned in literature, [[woodblock printing]] and movies.<ref name="Turnbull2003">{{cite book|last1=Turnbull|first1=Stephan|title=Kawanakajima 1553-64 Samurai power struggle|date=2003|publisher=Osprey|location=Oxford|isbn=9781472800220|edition=Unabridged.}}</ref>

The Shinano River system has a long history of hydroelectric power generation, with the first hydroelectric power plant in Japan being located in the system.<ref name="JPTimes2015"/> During the construction of a plant on the Shinano River in the Niigata Prefecture in July 1922, it was reported at the time that Korean workers were being mistreated and murdered.<ref name="Na2005">{{cite book|last1=Na|first1=Hanmee|title=The Fallacy of the Assimilation Rhetoric: The Roles of the Shinano River Incident of 1922 and the Great Kantō Earthquake of 1923 in Its Displacement|date=2005|url=https://books.google.com.au/books?id=pbF-NwAACAAJ|publisher=University of California, Berkeley|location=Berkeley|page=32|accessdate=8 July 2017}}</ref> The [[Shinano River incident]] involved 1,200 workers, approximately 600 of whom were Korean, who were subjected to regular mistreatment by their Japanese [[Construction foreman|foremen]]. The mistreatment included malnutrition, forced labour up to sixteen hours a day and severe beatings for those who tried to escape. News articles at the time alleged that up to 100 Koreans were killed during construction and that local farmers had reported seeing bodies floating down river.<ref name="Weiner1989">{{cite book|last1=Weiner|first1=Michael|title=The Origins of the Korean Community in Japan, 1910–1923|date=1989|publisher=Manchester University Press|isbn=9780719029875|pages=104–105|url=https://books.google.com.au/books?id=LcpRAQAAIAAJ|language=en}}</ref> This incident occurred following the [[Japan–Korea Treaty of 1910|annexation of Korea by Japan]] and was partially responsible for the development of trade unions for Korean workers in Japan.<ref name="Weiner2013">{{cite book|last1=Weiner|first1=Michael|title=Race and Migration in Imperial Japan|date=2013|publisher=Routledge|isbn=9781136121326|url=https://books.google.com.au/books?id=-e4DAQAAQBAJ|accessdate=8 July 2017|pages=75–77|language=en}}</ref>

Two Japanese [[Cruiser|naval cruisers]], one launched in [[Japanese cruiser Chikuma (1911)|1911]] and the second in [[Japanese cruiser Chikuma (1938)|1938]], were named after the Chikuma River.<ref>{{cite book|last1=Góralski|first1=Waldemar|title=The Japanese Cruiser Chikuma (Super Drawings in 3D)|date=2015|publisher=Kagero|isbn=9788364596629|url=https://www.abebooks.com/9788364596629/Japanese-Cruiser-Chikuma-Goralski-Waldemar-8364596624/plp|accessdate=5 July 2017}}</ref> A 1940s aircraft carrier was named after the old Shinano Province.<ref>{{cite book|last=Silverstone|first=Paul H.|title=Directory of the World's Capital Ships|year=1984|publisher=Hippocrene Books|location=New York|page=336|isbn=0-88254-979-0}}</ref>

==Course==
[[File:Chikuma River Yashima Bridge Nagano.jpg|thumb|Chikuma River, from Yashima Bridge, looking downstream toward Murayama Bridge, [[Nagano (city)]]]]
The Chikuma River rises in the northeastern foothills of Mount Kobushigatake in the Japanese Alps on the border of [[Saitama Prefecture|Saitama]], [[Yamanashi Prefecture|Yamanashi]] and Nagano Prefectures, partially in the [[Chichibu Tama Kai National Park]]<ref name="MLIT-river">{{cite web|author=Shinanogawa River Office|title=The Shinano River|url=http://www.hrr.mlit.go.jp/shinano/english/|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref><ref>{{cite web|title=National Parks of Japan – Encyclopedia of Japan|url=https://doyouknowjapan.com/nationalpark/index4.html|website=Encyclopedia of Japan|accessdate=5 July 2017|language=en}}</ref>

It joins with the Yochi River and flows roughly north to join the Yu River ({{coord|36.26|138.42|region:JP_type:river|name=Yu River}}) then turns northwest into an [[intermontane basin]] at [[Nagano (city)|Nagano City]] where it is joined by the Sai River from [[Matsumoto, Nagano|Matsumoto]] and the Hoshina River ({{coord|36.625|138.25|region:JP_type:river|name=Sai River}}). The Chikuma then changes direction and flows northeast from Nagano into Niigata Prefecture where it changes its name to the Shinano River.<ref name="Britannica">{{Britannica|540743|Shinano River}}</ref> The Shinano continues northeast to a [[confluence]] with Uono River between [[Ojiya, Niigata|Ojiya]] and [[Uonuma]] ({{coord|37.275|138.85|region:JP_type:river|name=Uono River}}).

After its confluence with Uono River, the Shinano is crossed by [[Koshiji Bridge]] and the [[Shinetsu Main Line|Shinetsu train line]] before emerging onto [[Echigo Province|Echigo Plains]] of the Niigata Prefecture at [[Sanjō, Niigata|Sanjō]]. After entering the Echigo Plains the river becomes [[deltaic]] and swampy due to its very small gradient (an average of 1 in 4000).<ref name="MLIT-river"/><ref name="Britannica"/><ref name="KyotoUni"/><ref name="Cheng2014"/>

The {{nihongo|Ōkōzu Channel|大河津分水路|Ōkōzu Bunsuiro}}, completed in the 1920s, diverts flood water northwest into the Sea of Japan while the river splits into a number of branches and continuing northeast. Approximately {{convert|25|km}} south of its mouth, the river turns north and flows towards Niigata.<ref name="MLIT-history"/>

[[File:NiigataCity AerialPhoto.jpg|thumb|left|River mouths in Niigata City – from the top: [[Agano River]]; Shinano River; Sekiya diversion channel]]
The Sekiya Diversion Channel was completed in the 1960s in response to flooding in Niigata continuing after construction of the Ōkōzu Channel. It is designed to mitigate flooding by diverting flood waters away from the city and straight into the Sea of Japan. The river turns northeast and flows through Niigata City for approximately {{convert|6|km}} before finally emptying into the Sea of Japan.<ref name="KyotoUni"/><ref name="MLIT-river"/><ref name="Britannica"/>

The river is crossed multiple times as it meanders its way through Niigata, including by the [[Bandai Bridge]] which was, when it was originally built in 1886, the longest bridge in Japan at {{convert|782|m}}. The current Bandai Bridge, built in 1929 and designated as a nationally [[Important Cultural Property (Japan)|important cultural property]], is only {{convert|306.9|m}} long. This is also in stark contrast with the river's {{convert|720|m|adj=mid}} width at the Ohkouzu Diversion Channel.<ref name="MLIT-history"/><ref name="Bandai-Bridge">{{cite web|title=Bandai Bridge: An Iconic Landmark of Niigata City – Japan Info|url=http://jpninfo.com/71933|website=Japan Info|accessdate=4 July 2017}}</ref>

{{clear}}

===Ōkōzu Diversion Channel===
Due to seasonal high rainfall in the Shinano's watershed the fertile farmlands on the Niigata plain were subjected to flooding every three to four years which destroyed crops, particularly rice, and villages.<ref name="Sassa2008">{{cite book|last1=Sassa|first1=Kyoji|last2=Canuti|first2=Paolo|title=Landslides – Disaster Risk Reduction|date=2008|publisher=Springer Science & Business Media|isbn=9783540699668|url=https://books.google.com.au/books?id=Ed5giaYxYcIC|accessdate=3 July 2017|language=en}}</ref> Attempts from local residents to secure funding to build a diversion channel began in the mid-early eighteenth century, during the [[Kyōhō]] era.<ref name="KyotoUni"/> Government support was not secured until the early twentieth century following severe flooding and inundation in 1896.<ref name="MLIT-history"/><ref name="Cheng2014"/>

[[File:Okozu Canal under construction.JPG|thumb|alt=Image showing an excavation being cut into hills with crisscrossed railway tracks.|Construction of the Ōkōzu Channel.]]
Construction work on the {{convert|10|km|mi|adj=mid|-long}} {{nihongo|Ōkōzu Channel|大河津分水路|Ōkōzu Bunsuiro}} began in 1909 and concluded in 1922. The success of the channel was short-lived, however, as the floodgate collapsed in 1927 due to erosion of the channel bed and was not fully repaired until 1931.<ref name="MLIT-history"/><ref name="JapanDams">{{cite book|author1=Japan Commission on Large Dams|title=Dams in Japan: Past, Present and Future|date=2009|publisher=CRC Press|isbn=9780415494328|url=https://books.google.com.au/books?id=If54C_G7otYC|accessdate=3 July 2017|language=en}}</ref>{{rp|52}}<ref name="Cheng2014"/><ref name="JSCE">{{cite web|title=Subcommittee on Research of the Old Movable Weir in the Ohkouzu Diversion Channel|url=http://www.jsce.or.jp/committee/concrete/e/newsletter/newsletter33/Newsletter33_files/committee272.html|publisher=[[Japan Society of Civil Engineers]]|accessdate=3 July 2017|language=ja}}</ref>

The construction of the diversion channel has resulted in marsh fields drying on the Niigata plain which allows for greater production. Likewise, drier land has also allowed for the construction of infrastructure such as expressways and the [[Shinkansen]] express-train network, to support a greater population in the area.<ref name="MLIT-history"/>

A new weir wall was constructed between 1992 and 2000 due to safety concerns with the original wall. Construction was planned to limit negative affects on scenery and wildlife. To this end, natural stones were used for the exterior and fishways were included in the design.<ref name="MLIT-weirs">{{cite web|author=Shinanogawa River Office|title=Weirs|url=http://www.hrr.mlit.go.jp/shinano/english/weir/weirs.html|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref>

===Sekiya Diversion Channel===
[[File:新潟大堰.jpg|150px|thumb|Sekiya ocean gate.]]
Flooding in the Niigata area continued following the construction of the Ōkōzu Channel. As a result, another channel, which was originally planned in the [[Edo period]] (1700s–1800s), was built on the western outskirts of Niigata City to further mitigate the risk of flooding and to help prevent saltwater intrusion into the Shinano estuary. The Sekiya Diversion Channel was originally to be funded by the Niigata Prefecture; however the [[1964 Niigata earthquake]] resulted in the funds no longer being available so it was adopted as a national project.<ref name="MLIT-Sekiyaru">{{cite web|author=Shinano River Downstream River Office|title=Sekiyaru branch|url=http://www.hrr.mlit.go.jp/shinage/shisetsu/sekibun/sekibun.html|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref>

[[File:信濃川水門.jpg|150px|thumb|Shinano River gate.]]
Construction of the Sekiya Diversion Channel commenced in 1968 and concluded in 1973 with a channel {{convert|1.8|km}} long and {{convert|240|-|280|m}} wide. The channel provides another alternate path for sediment to be directed straight out to sea and away from the Niigata port. The channel is crossed by the [[Echigo Line]] and the [[Japan National Route 402|National Route 402]] (excavated materials from the channel were used in the construction of Route 402).<ref name="KyotoUni">{{cite book|author1=Hydrology and Water Resources Research Laboratory|editor1-last=Ibbitt|editor1-first=Richard|editor2-last=Takara|editor2-first=Kaoru|editor3-last=Pawitan|editor3-first=Hidayat|title=Shinano-gawa|date=2002|publisher=Kyoto University|url=http://hywr.kuciv.kyoto-u.ac.jp/ihp/riverCatalogue/Vol_04/03_Japan-10.pdf|accessdate=3 July 2017|format=PDF|chapter=3. Japan|volume=4}}</ref><ref name="Liu2000">{{cite book|editor1-last=Liu|editor1-first=Phillip|title=Advances in Coastal and Ocean Engineering|date=2000|publisher=World Scientific|isbn=9789814493970|url=https://books.google.com.au/books?id=jGbVCgAAQBAJ|accessdate=4 July 2017|language=en}}</ref>

===Major dams===
There are a number of major dams in the Shinano River system, but not on the main river itself, rather its tributaries are extensively dammed and used for electricity generation as well as water for irrigation. The major dams in the system are listed below:<ref name="KyotoUni"/>
* The [[Shin-Takasegawa Pumped Storage Station|Takase Dam]], on the Takase River, a tributary of the Sai River, holds {{convert|76.2e6|m3}} and is the tallest of its size in Japan.<ref name="ASCE">{{cite book|author1=Task Committee on Pumped Storage of the Committee on Hydropower of the Energy Division of the American Society of Civil Engineers|title=Hydroelectric pumped storage technology : international experience|date=1996|publisher=[[American Society of Civil Engineers]]|location=New York, NY|isbn=0784401446}}</ref> It is also the second tallest dam in Japan, after the [[Kurobe Dam]].<ref>{{cite web|title=Takase Dam|url=http://damnet.or.jp/cgi-bin/binranA/All.cgi?db4=1027|publisher=Japan Dam Handbook|language=Japanese|accessdate=8 August 2011}}</ref>
* The Nanakura Dam, which is part of the Takase Dam system, holds {{convert|32.5e6|m3}}.<ref name="ASCE"/>
* The [[Ōmachi Dam]] is further downstream from the Nanakura Dam and holds {{convert|33.9e6|m3}}.<ref name="Damnet-Omachi">{{cite web|title=Omachi Dam|url=http://damnet.or.jp/cgi-bin/binranA/All.cgi?db4=1032|publisher=Japan Dam Handbook|accessdate=4 July 2017|language=japanese}}</ref>
* The [[Nagawado Dam]] is on the Azusa River, another tributary of the Sai, holds {{convert|123e6|m3}} and is followed downstream by a number of smaller dams including the [[Midono Dam]] and [[Inekoki Dam]].<ref name="Damnet-Nagawado">{{cite web|title=Nagawado Dam|url=http://damnet.or.jp/cgi-bin/binranA/enAll.cgi?db4=1018|publisher=Japan Dam Handbook|accessdate=4 July 2017|language=japanese}}</ref><ref name="Damnet-Midono">{{cite web|title=Midono Dam|url=http://damnet.or.jp/cgi-bin/binranA/enAll.cgi?db4=1022|publisher=Japan Dam Handbook|accessdate=4 July 2017|language=japanese}}</ref><ref name="Damnet-Inekoki">{{cite web|title=Inekoki Dam|url=http://damnet.or.jp/cgi-bin/binranA/enAll.cgi?db4=1019|publisher=Japan Dam Handbook|accessdate=4 July 2017|language=japanese}}</ref>
* The [[Sagurigawa Dam]] sits on the Sankuni River which is a tributary of the Uono River. It holds {{convert|27.5e6|m3}} and is used for a range of purposes including storage for power generation, flood control and water for irrigation.<ref name="Damnet-Sagurigawa">{{cite web|title=Sagurigawa Dam|url=http://damnet.or.jp/cgi-bin/binranA/enAll.cgi?db4=0787|publisher=Japan Dam Handbook|accessdate=4 July 2017|language=japanese}}</ref>

==Watershed==
[[File:SaiRiverJoinsChikumaRiver.jpg|thumb|alt=Aerial image showing two rivers meandering towards confluence near the bottom of the image.|Looking southwest, with the Sai River on the right and the Chikuma on the left ({{coord|36.625|138.25|region:JP_type:river|name=Sai River}})]]
The {{convert|11900|km2}} basin of the Shinano-Chikuma River system is the third largest in Japan and at {{convert|367|km}}, is the longest river in the country. The river system supports a population of around 3&nbsp;million ({{as of|2009|lc=y}}) but supports significant agriculture and electricity generation.<ref name="KyotoUni"/><ref name="JapanDams"/>{{rp|182}} The river has 880 branches which is the second highest in Japan after the [[Yodo River]].<ref name="MLIT-basin"/>

The discharge of the river averages {{convert|503|m3}}, with a mean maximum of {{convert|3776|m3}} to mean minimum of {{convert|91|m3}}. In addition to this discharge, {{convert|30.4|m3}} of water is used for municipal and industrial supply across the basin.<ref name="KyotoUni"/>

The Chikuma River originates in the Japanese Alps at altitudes of above {{convert|2000|m}} and has a basin in its own right of {{convert|7163|km2}}. The Chikuma continues generally north-northeast joining with the Sai and changing name to the Shinano, after {{convert|214|km}}. The Chikuma, therefore, includes around sixty percent of the whole river system's basin and around 58 percent of the river's length.<ref name="KyotoUni"/>

In the upper reaches of the river, where it is known as the Chikuma, only around ten percent of the land is flat, agricultural land and around {{convert|49600|ha}} of it is irrigated. By the time the river flows onto the Echigo Plain, however, much more land is devoted to agriculture and there is huge potential for irrigation, especially due to influence of the Ohkouz Channel and weir. The abundance of water and fertile soils has led to this area being the one of the best rice producing areas in Japan.<ref name="KyotoUni"/><ref name="Wanderer">{{cite web|title=Longest Rivers in Japan|url=http://www.japanesewanderer.com/longest-rivers-in-japan/|website=Japan Travel Guides|accessdate=3 July 2017}}</ref>

Rainfall varies considerably in the Shinano basin. In the middle part of the Chikuma River, near its confluence with the Sai River, rainfall is some of the lowest in Japan, generally staying below {{convert|1000|mm}}. The low precipitation is primarily due to its encirclement by the three ranges which make up the Japanese Alps and by the [[Jōshin'etsu-kōgen National Park]]. However, the upper reaches of the Chikuma and Sai Rivers and the lower part of the Chikuma River (where it changes name to the Shinano River) receive {{convert|1200|-|2300|mm}} annually. In the central areas of the Shinano River, especially in the Uono Basin, precipitation increases to around {{convert|2200|-|3000|mm}}; this area receives some of the highest winter snow falls in Japan with 40–50% of this precipitation falling as snow. The heavy snow melt is responsible for much of flooding to affect the Echigo, but also allows for the hydroelectricity generation and regular irrigation.<ref name="KyotoUni"/><ref name="MLIT-climate">{{cite web|author=Shinanogawa River Office|title=Climate|url=http://www.hrr.mlit.go.jp/shinano/english/basin/climate.html|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref>

==Ecology==
[[File:Chikuma River from Komoroohashi Bridge.jpg|thumb|left|alt=River moving left to right in the mid ground surrounded by green grass and trees and mountains in the background.|Chikuma River near [[Komoro, Nagano|Komoro]].]]
The Shinano basin supports a large range of plant life, including over 1,100 species of plant which grow on the river bank, in the river bed or more broadly. The basin also supports a large range of animal life both in and around the river. However, the development of the river has threatened the continuing existence of a number of different species. Across the country, thirty to fifty (or higher) percent of endangered species are from freshwater river systems and the impact on the Shinano river system is also clear. Primarily this affects fish and amphibians due to their reliance on the river. The construction of weirs and dams to support agriculture and industry as well as the introduction of invasive species and pollution have been the main causes of ecosystem degradation. The Shinano basin provides a habitat for around twenty-five percent of Japan's fish species (around fifty-five of the 200 fish species living in Japan) including both [[endemic]] freshwater fish as well as [[diadromous fish]].<ref name="MLIT-living">{{cite web|author=Shinanogawa River Office|title=Living things|url=http://www.hrr.mlit.go.jp/shinano/english/basin/living.html|website=Hokuriku Regional Development Bureau|publisher=[[Ministry of Land, Infrastructure, Transport and Tourism]]|accessdate=3 July 2017|language=en}}</ref><ref name="Nakano2012">{{cite book|last1=Nakano|first1=Shin-ichi|last2=Yahara|first2=Tetsukazu|last3=Nakashizuka|first3=Tohru|title=The Biodiversity Observation Network in the Asia-Pacific Region: Toward Further Development of Monitoring|date=2012|publisher=Springer Science & Business Media|isbn=9784431540328|pages=230–232|url=https://books.google.com.au/books?id=iI7BbU9kjvQC|accessdate=5 July 2017|language=en}}</ref>

The construction of large dams, especially in the mid and upper reaches of the system have significantly affected the ability of fish to migrate up and down the river, and into the Sea of Japan. There has also been a significant increase in the amount of fishing which takes place in the system which is associated with the introduction of invasive fish species and waterbirds into the system. The development of the river, and human settlement, has also resulted in the environmental degradation of key fish habitat. Changes in the system have affected its ability to support and maintain fish species which are endemic to the river. Some actions have been taken to overcome these issues, including prohibitions on fishing salmon during breeding and stocking certain areas for fishing, especially in areas where Tsukeba fish shacks (popup stores along the riverbank) are regularly set up.<ref name="Craig2016">{{cite book|last1=Craig|first1=John F.|title=Freshwater Fisheries Ecology|date=2016|publisher=John Wiley & Sons|isbn=9781118394403|url=https://books.google.com.au/books?id=ppdmCwAAQBAJ|accessdate=3 July 2017|language=en}}</ref><ref>{{cite web|title=Chikuma River Fish Cuisine|url=http://machiaruki.net/unique_nagano/detail.php?id=17|publisher=Unique Nagano|accessdate=5 July 2017|language=ja}}</ref>

The river system has also long been home to bird life. The negative effects of human development have not as significantly affected birds as fish due to the more limited changes to bird habitat (which includes the forests which still remain on surrounding mountains). There are more than 130 species of birds which frequent the river system, these include starlings and ducks as well as migratory birds such as cranes and ibis.<ref name="MLIT-living"/><ref name="Nakano2012"/>

==Economy==
===Electricity production===
The Shinano River system, particularly in its upper reaches (Chikuma River) and in the Sai basin, is used for hydroelectric power generation due to the steep gradient in its upper reaches and its high discharge producing, as a whole, 2,618 megawatts. While the construction of hydroelectric power stations began before World War II, it significantly increased following the war. These power plants, such as the Shimofanato Power Station and the 450,000 kilowatt [[JR East]] Shinano River Hydropower Station near Ojiya, supply Tokyo.<ref name="JREast">{{cite web|title=Measures to Prevent Global Warming|url=https://www.jreast.co.jp/e/environment/pdf_2005/report2005e_30_33.pdf|website=JR East Group|accessdate=5 July 2017|pages=30–33|format=PDF|year=2005}}</ref>

There are several hydroelectric power plants operated by [[Tokyo Electric Power Company]] in the river system. The [[Shin-Takasegawa Pumped Storage Station]] is a significant power plant located on the Takase River near [[Ōmachi, Nagano|Ōmachi]], it boasts the second tallest dam (and the tallest rock-filled embankment) in Japan, and an output of 1280 megawatts.<ref name="KyotoUni"/><ref name="Infoplease">{{cite web|title=World's Highest Dams|url=http://www.infoplease.com/ipa/A0113468.html|publisher=Infoplease|accessdate=4 July 2017}}</ref>

Additionally, Japan's oldest hydroelectric power plant is located in the Shinano River system. The Miyashiro Power Plant No. 1 was opened by the Azumi Electric Power Company in 1904 and has, since then, been in continual operation, currently operated by [[Chubu Electric Power Company]].<ref name="JPTimes2015">{{cite news|last1=Shimbun|first1=Chunichi|title=Tours provide renewed interest in Japan's oldest hydro power plant|url=http://www.japantimes.co.jp/news/2015/11/16/national/tours-provide-renewed-interest-japans-oldest-hydro-power-plant/|accessdate=4 July 2017|work=Japan Times|date=16 November 2015}}</ref><ref name="Ishihara2016">{{cite journal|last1=Ishihara|first1=Shinsuke|title=Japanese Facility Joins Hydro Hall of Fame|journal=HRW-Hydro Review Worldwide|date=12 January 2016|volume=24|issue=6|url=http://www.hydroworld.com/articles/print/volume-24/issue-6/features/japanese-facility-joins-hydro-hall-of-fame.html|accessdate=4 July 2017}}</ref>

===Tourism===
Tourism is a major industry in the Shinano River basin as there are a number of attractions in the area. The Shinano River system attracts a number of tourists from across the country for [[angling]] and to experience Tsukeba fish shacks which are set up along the river bank and bed to cook fish as they are caught.<ref name="KyotoUni"/><ref name="Craig2016"/>

The hot springs along the Chikuma River for example from tourists into the upper reaches of the river. The high rate of snow in the mountains surrounding both the Chikuma and Shinano Rivers make them attractive places for snow sports with a number of ski resorts scattered throughout the mountains.<ref name="KyotoUni"/> The [[1998 Winter Olympics]], which were held in Nagano, indicate the large number of locations for snow sports in the area.<ref name=Olympics>{{cite web|title=The Olympic Winter Games Factsheet|url=http://www.olympic.org/Documents/Reference_documents_Factsheets/The_Olympic_Winter_Games.pdf|publisher=International Olympic Committee|accessdate=5 August 2012}}</ref>

In addition to these natural attractions, human involvement in the area is also responsible for making tourism a large part of the regional economy. Every year, around 6.5–7&nbsp;million people visit the [[Zenkō-ji]] Buddhist template in Nagano.<ref name="KyotoUni"/> It is believed that visiting the template will grant salvation. This has resulted in the head temple of the [[Tendai]] sect being a significant attraction for tourists throughout its 1,400-year history.<ref name="Goldsmith2008"/>{{rp|33}}<ref>{{cite web|last1=Association|first1=Central Japan Tourism Promotion|title=Zenkoji Buddhist Temple|url=http://en.go-centraljapan.jp/place/detail_131.html|website=GO! Central Japan|publisher=Central Japan Tourism Association|accessdate=5 July 2017}}</ref>

==See also==
* [[Shinano Province]]
* [[Shinano, Nagano]]
* [[List of rivers of Japan]]

==References==
{{reflist|30em}}

{{coord|37|23|17|N|138|48|39|E|region:JP_type:river|display=title}}
{{Rivers of Japan}}
{{Authority control}}

[[Category:Rivers of Nagano Prefecture]]
[[Category:Rivers of Niigata Prefecture]]
[[Category:Water transport in Japan]]