Tokyo Dam

0692-Ogouchi Dam

Tokyo Dam
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Location: Okutama-cho, Nishitama-gun, Tokyo
Date of interview: July 18, 2004

View of the embankment from the left bank

View of the embankment from the left bank

First time on this site! A dam in Tokyo. Well, when you think about it, we have come a long way. But it is almost on the border of Yamanashi Prefecture (lol).
Previously.Kuzunogawa DamFrom there, we passed through Matsuhime Pass and ran along the left bank of Lake Okutama. There was very little traffic around the Matsuhime Pass, but as soon as we reached the lakeshore road, we were surprised by the sheer volume of traffic.Yahagi DamThe atmosphere is totally different from that of the previous day. When I arrived at the dam site, there were a huge number of people. As expected of the imperial capital, it is different.
Lake Okutama was an artificial lake created by the Ogouchi Dam.

Flood discharge gate

Flood discharge gate

The water from the dam lake was not reaching the gate, as if it had hardly ever been used. I always seemed to hear the name of this dam on the news of droughts, and I felt sure of it.

Electric bulletin board showing water level, etc.

It seems to be displayed in real time. A little bit of water is being discharged for water utilization....


I found what looks like an incline. It looks like we can go near it, but we have not checked yet due to lack of time.

View of the embankment from the left bank

It is 149 meters high, but I did not feel it was as high as I thought it would be.

View downstream from the top

Hinged to the dike is the No. 1 intake facility. The white building on the left is the Tama River No. 1 Power Plant. This power station is under the jurisdiction of the Tokyo Metropolitan Transportation Bureau. Is the electricity for the subway provided here? If so, it can be said that this dam is truly for the people of Tokyo.

No. 2 Water Intake Facility

At first I thought it was just a heliport, but it seems to be an intake gate. Can you see the shutter-like thing on the dam lake side?
Incidentally, the first intake facility is used when the water level drops below 470 m above sea level, and the second facility is used not only for emergency discharge during drought, but also for the discharge of warm surface water.

View of the top edge from the left bank

It is a wide and long skyline. Due to time constraints, we did not go to the other side of the river, but it seems quite far away.

View of flood discharge gate

The flood discharge has five 12.1m wide by 7.2m high roller gates.

Caracalla conduit

The flow once flows through here, and then falls down on the other side. There is also a reduction structure on the other side of the channel. Incidentally, there is no sign of recent use. It is empty.

Gate from downstream

It is a strange sight.

Okutama Water and Greenery Fureai Kan

We took a quick tour of this place at the end of the day and had our meals here. I think I had soba or udon, but I don't remember.
The inside of the building is an interesting spiral structure, but I didn't have much time to look at the exhibits and other details (sweat).

dam characteristics

Modelnon-overflow type straight linegravity-fed concrete dam
ObjectiveWater for water supply/power generation
Bank height149m
Bank length353m
Summit width12.6m
Dam volume1,675,680m3
water (esp. cool, fresh water, e.g. drinking water)
Watershed Area262.88 km2
Reservoir area425ha
Total storage capacity189,100,000m3
Effective water storage capacity185,400,000m3
Name of Dam LakeLake Okutama
River NameTama River System Tama River
Year of launch1936.
Year Completed1957
Access to D@MFrom Otsuki IC of Chuo Expressway
Get off at Otsuki IC and turn left on Route 20→go east on National Road→turn left on Route 139→turn left on Route 139
On the way, we saw the Fukashiro Dam and the Kuzunogawa Dam, and continued northward.
Crossing the bridge over Lake Okutama (Fukayama Bridge)
If you follow Route 411 (Ome Kaido) eastward, you will naturally arrive at the dam.

Other facilities/observations

Parking lotIt is an all-around dam. And there are a lot of people.
Are people in Tokyo still seeking healing in nature, away from the hustle and bustle of the city?
Or is it a cheap and easy way to go?
Ha! Or are we all hidden dam maniacs!
PR Exhibition Hall

Accommodations that may be close to Ogawachi Dam

This article was written by.
Shin Jinma

Dam enthusiast who loves Momosuke Fukuzawa / Dampedia and Dam News administrator / Certified Dammeister (01-018) by the Japan Dam Foundation / Started selling discharge caution goods.

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  1. ぴろ says:

    The residual water discharge, we used it in both the recent typhoon No. 12 and No. 15... ♪

  2. [...] A documentary film screening of the Tokyo Metropolitan Government's water reservoir, the Ogawachi Dam, will be held at the Tokyo Metropolitan Waterworks History Museum from June 20 (Sat) to 21 (Sun). The Tokyo Metropolitan Waterworks History Museum will present a large number of video materials planned and produced by the Bureau of Waterworks of the Tokyo Metropolitan [...]

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