Vicinity of Tsukuba and history of Tone river improvement

Kamoto10 Nov. 2014

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Kinu R.

Kokai R.

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The Kokai River is characterized by the large share of its paddy area in the basin. These paddy fields are supported by irrigation water from the Kinu River and water returned from the 10,000 ha of paddy fields. Over 300 water intakes for agriculture water supply are located on the main Kokai River and its tributaries. The area irrigated by these facilities totals some 24,000 ha. On the other hand, irrigation and drainage canals including Fukuoka, Oka and Toyota Weir known as the three major weirs in Kanto where constructed in the downstream reaches of the Kokai River. These three weirs are well known for using the pond method to pump river water to a high elevation and store a large amount of water in the channel as if it storing water in a pond.

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Tone River and Retarding Basin

Tokyo

Tone R.

Watarase R.

Kinu R.

Kasumigaura L.

Kokai R.

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16,840 km2

322 km

Tanaka

Sugao

InatoiTone Canal

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TX

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Area and Volume ○Inatoi:             4.48km2 95.53 million m3

○Tanaka:          11.75km2 30.80 million m3

○Sugao:              5.92km2 28.50 million m3

○Watarase:      33.00km2 170.68 million m3

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1/200 Basin average Precipitation:

319.0 mm/3‐days

Control by up stream dams: 5,500 m3/s

Peak DesignFlood :22,000 m3/sat Yattajima

The peak discharge from Kinuand Kokai are controlled by 

retarding basin

The peak discharge from Watarase River is controlled by 

retarding basin

Unit: m3/s  

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River System 

Name of dam

Year of Completion

Catch‐mentarea(km2)

Reservoir area(km2)

Dam height (m)

Dam length (m)

Effective Storage capacity(mil. 3)

Flood control volume (mil. m3)

Up‐stream  Tone

Yagisawa 1967 167.4 5.67 131.0 352 175.80 22.10

Naramata 1991 95.4 2.00 158.0 85.00 13.00

Fujiwara 1959 207.2 1.69 95.0 23.0 35.89 21.20

Aimata 1959 110.8 0.98 67.0 80 20.00 9.40

Sonohara 1966 492.2 0.91 76.5 128 14.14 14.14

Shimo‐kubo

1968 322.9 3.27 129.0 303 120.0 35.00

sum 1395.9 14.52 450.83 114.84

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River System 

Name of dam

Year of Completion

Catch‐mentarea(km2)

Reservoir area(km2)

Dam height (m)

Dam length (m)

Effective Storage capacity(mil. m3)

Flood control volume (mil. m3)

Watara‐se

Kusaki 1976 254.0 1.70 140.0 405 50.50 20.00

Kinu Ikari 1957 271.2 3.10 112.0 267 46.00 14.00

Kawa‐mata

1966 179.2 2.59 117.0 131 73.10 24.50

Kawaji 1984 503.0 2.20 140.0 321 76.00 36.00

Yunishi‐gawa

2012 102.0 1.98 119.0 320 70.00 30.00

Sum 1055.4 9.87 265.10 104.50

Total 766.43 239.34

Ikari Dam

Kawamata Dam

Kinugaw

a River

Tonegawa River

Locations of the Group of Dams on Kinugawa River

Yanba Dam(under construction)

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Yunishigawa Dam (flooded water test)

Kawaji Dam

Kinunuma (headwaters)

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1. Old bank2.   M33 (1900) 3.   S14  (1939)4.   S24  (1949)5.   S55  (1980)6.   Heisei (1989 ~)

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1783 Tenmei 3 Volcanic Eruption Mt. Asama

1786 Tenmei 6 Flood

1896 Meiji 29 Flood

1910 Meiji 43 Flood

1938 Showa 13 Flood in Kasumi‐ga‐uara

1947 Showa 22 Flood by typhoon Katharine 

1986 Showa 61 Flood in Kokai River 

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The Hakojima Retarding Basin 

Kokai RiverOya River

Source: The Shimodate Office of River, Kanto Regional Development Bureau, The Ministry of Land, Infrastructure, Transport and Tourism, 

The Hakojima Retarding Basin 

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“Mitsuka” (or “Mizuka”) refers to a foundation that is elevated in preparation for flooding, including structures on such foundations, if any. Many of them are still seen in low-lying areas in the Kanto region, where people used to suffer from frequent floods.

The Yoshida-ke Mituska has been confirmed to be the only one left in downtown Kuki. On June 26, 2008, KurihashiTown (former Kuki City) designated it as a municipal cultural asset, recognizing its historical importance for passing down local wisdom and the history of old inn town Kurihashi to the future generations.

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Nobusima‐Shinden along Kinu River 2014.11.2

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“Kasumi-tei,” or open levees, is built by placing multiple levees to overlap each other’s upstream and downstream tips so as to prevent floodwaters from overflowing. Kasumi-tei has been commonly applied particularly to rapid-current streams, such as ones running down through alluvial fans, since years before renovation in modern times.Each levee used for Kasumi-tei looks standing alone,

separate from each other, on a plan view. Functionally, however, they are not apart from one another, extending themselves upstream and downstream adequately enough to partially overlap each other. The key is that river water will not overflow because the river water level is lower towards downstream according to the river bed slope, or the slope of the alluvial fan in a broader sense.

from Nakao Tadahiko “河川工学の基礎と防災

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The following are some advantages of Kasumi-tei (1/2):

Kasumi-tei works like guide levees, which direct the stream towards the center of the river because each kasumi-tei levee, particularly its downstream part, is angled so as to lead the stream away from the residential and farming area to the center of the river.

Because of its unique design, it is the downstream part of each levee that is exposed to the dynamic flow of the rapid current. Thus, the upstream part can avoid the direct hit by floodwaters. This helps us focus more on the downstream part of the levee in terms of levee protection, instead of the entire length of the river.

Even if the downstream part of a kasumi-tei levee breaches, the residential and farming areas will still be protected from the direct hit by rapid floodwaters, because the upstream part of the adjacent, downstream levee works as a secondary levee.

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The following are some advantages of Kasumi-tei (2/2):

The gap between two kasumi-tei levees also works as a retarding basin. Traditionally, however, the gap has been considered as extra room or buffer zone rather than officially including it as part of design volume.

As the river water level continues rising, floodwaters will start overflowing slowly from the openings of kasumi-tei. However, damage is expected to be not so serious because the floodwaters are not the rapid current from the main stream but the ones with almost no velocity.

Kasumi-tei does not require large structures, such as water gates, to lead tributaries into the main stream. They can merge to the main stream through the openings of kasumi-tei. Reversely, floodwaters from the main stream can be led to tributaries through the openings.

Since early times, many communities have adopted kasumi-tei for rapid-current rivers because of these advantages. In recent years, however, kasumi-tei has been turned into continuous levees by connecting adjacent levees probably because its discontinuous design may not look safe enough.

利根川水系霞ヶ浦圏域河川整備計画茨城県より

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Sin‐tone R.

Ono R.

Sakura R.

Koise R.

Kita‐ura lake 

Kasumiga‐Uralake

Kasumiga‐Ura

Catchment area 1,915 km²

Surface area 220 km²

Average depth 4 m

Max. depth 7 m

Water volume 0.848 km³

Shore length1 252 km

Surface elevation 0.16 m

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Photos in 2013 Sep 10

Aoki Weir

Location Sakuragawa City, Ibaraki, JapanName of river SakuraBeneficial area 61 haHeight of the weir 5 mManager of Facility Yamato & Sakura Water Supply AssociationLength of the weir 19 mStyle of the weir Semi Fixed Weir (Steel Slide Gate)Construction year 1998

Hojo Weir

Location Tsukuba CityName of river SakuraBeneficial area 231.8 haHeight of the weir 3.1 mManager of Facility Tsukuba City Land Improvement

OrganizationLength of the weir 36.3 mStyle of the weir Inflatable Rubber WeirConstruction year 1999

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Photo in 2013 Sep 10  2013 Oct. 19

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Flexible water usage at the 

drought in 2001From industry to 

irrigation 

＜Town development along TX in Ibaraki＞8 locations    about 1,700 ha 

(Town redemarcation project)Planned population:  about 100,000Planned housing land: about 1,000 ha     

Shimana &

Fukudatsubo

Municipality Tsukubamirai Tsukuba Tsukuba

Primarycontractor

Ibaraki Pref . Ibaraki Pref . Ibaraki Pref .

Dev elopmentarea

275ha 243ha 168ha

Plannedpopulation

16,000 15,000 11,000

Kamikawarazaki& Nakanishi

LocationIna &

Yawaraky uury ou

Moriy a Sta. Nakane &

Area Kondadai

Municipality Moriy a Moriy a Tsukuba Tsukuba Tsukuba

Primarycontractor

Moriy a association UR UR UR

Dev elopmentarea

39 ha 40 ha 293 ha 485 ha 190 ha

Plannedpopulation

3,800 2,400 21,000 25,000 8,000

Location Kay amaru KatsuragiMoriy ahigashi

Ina & Yawarakyuryobu（Miraidaira）

Kayamaru（Midorino）

Shimana & Fukudatsubo（Banpakukinenkoen）

Kamikawarazaki& Nakanishi

Katsuragi（Kenkyugakuen） Nakane & Kondadai

Moriyahigashi

Moriya（Moriya）

Chiba Pref.

Outline of 8 locationsTsukuba Sta.

Midorino Sta.

Kenkyugakuen Sta.

Moriya Sta.

Miraidaira Sta.

Banpakukinen Sta.

Development along the TX line

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１ Town development along the TX line (Katsuragi Area)

Aerial view of Katsuragi Area after project

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１ Town development along the TX line (Katsuragi Area)

River improvement with town development along TX

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２ Rainwater drainage measures

Yata River(Yata‐gawa)

Hasunuma River (Hasunuma-gawa)

Nishiyata River(Nishiyata‐gawa)

Takaoka River(Takaoka‐gawa)

Current

Current

Current

Current

After improvement

After improvement

After improvement

After improvement

つくばエクスプレス

東光台研究団地

Rainwater drainage measures within the project area

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Hasunuma‐gawa regulating pond No.1

Hasunuma‐gawa regulating pond No.2 

Katsuragi‐gawa regulating pond

Regulating pond

Regulating pond

２ Rainwater drainage measures

Rainfall detention/infiltration measures

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Private houses

Roads

Large parks

Small parks

Schools

Commercial/industrial facilities

２ Rainwater drainage measures

Tone Canal

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The construction of the Tone Canal by private initiative began in 1889 to shorten the route of water transport connecting the Tone and Edo rivers when waterborne traffic was bustling. The inland canal stretching about 9 kilometerswas completed in 1890. The canal was designed by Dutch engineer AnthonieThomas Lubertus Rouwenhorst Mulderand, unlike many other canals in Japan, it is curved to create beautiful scenery. The canal shortened the shipping route by some 40 kilometers, thereby increasing the speed of shipment from rice‐producing areas along the Tone River to Tokyo, a major consumption center. 1 outer ring steamboat and Takase ship, during the height, about 100 boats a day had been operated. The canal saw busy traffic through the first half of the 20th century . Over time, it has become the era of the automobile and railway.In 1941, Its embankments were destroyed by a typhoon and it was acquired by the country in 1942, thus ending a half century of its history in waterway shipping.Then, it had become the interim water channel to compensate for the water shortage in Tokyo temporary.  It showed a quiet appearance after finishing also the role now, and it is also referred to as “Toneunga eco‐museum”. 

Noda city is famous for Shoyu (soy source) production. Kikoman Company originates here.     

Thank for your attention

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