0947-Managawa Dam

Date of interview: Saturday, July 27, 2013

On this day, I came to Managawa Dam to attend a talk by a fellow dam enthusiast, Mr. Yajaku, and a tour of the embankment as part of a seasonal event to familiarize myself with the forest and lake.

View of the upstream face of the embankment from the left bank

It is midsummer, but the heat is gone when you see the dam. As you can see, the Managawa Dam is an arch dam.

Acceptance of tours inside the levee is complete.

Since the tour inside the embankment of the Managawa River Dam requires prior registration, you will receive a pass after a quick check-in. The mascot character of the Managawa Dam, Princess Mana, is depicted on the pass.

Yajaku's talk venue

Mr. Yajaku's talks are always the most interesting presentations on flood control and other topics. It is not easy for the public to see Mr. Yajaku's talk unless it is an opportunity like this, but it was impressive that Mr. Yajaku gave his presentation at the Managawa Dam every year during this period. (By the way, the picture was taken during the waiting time, so the number of participants was still very small.)

Managawa River Dam Management Branch Office, Kuzuryu River Dam Integrated Management Office, Kinki Regional Development Bureau

Why are the names of the buildings of dams under direct control so cool?

elevator in an embankment

After a briefing in the control center, visitors will take the elevator located inside the control center to the dike.

corridor connecting an annex to a pond-side building (in traditional palatial-style architecture)

This location is a long audit corridor, although it is not yet within the dike, but within the bedrock.

Downstream side of the left bank, looking downstream from the middle of the embankment

This is a valuable sight since it is usually inaccessible. The Managawa Dam is an arch dam with a central overflow type asymmetrical parabolic arch unequal-thickness concrete dam, the same type as the Seirenji Dam in Mie Prefecture. Compared to parabolic arch dams such as the Yahagi Dam, the Managawa Dam has less overhang.

Commentary by staff

This is an explanation by an employee of the Managawa Dam. The explanation was easy to understand for children.

Managawa Dam Operation Method

The explanation by the staff is easy to understand, but this sign is also easy to understand. Incidentally, the Ashiba River next to the ridge on the other side of the river suffered severe damage from the 2004 heavy rainfall in Fukui, after the dam construction plan was abandoned. However, the Managawa River, which receives the same amount of heavy rainfall as the Ashiba River, was not damaged by the Managawa Dam, and this led to an interesting episode in which the Ashiba River dam construction plan was put into action again.

View of the left bank side of the downstream face of the dike

階段で移動することはありませんでしたが、もし階段だったら…💦

leakage meter

This device is used to measure the amount of leakage. A pole is erected to prevent accidental kicking.

Conduit gate operation room interior

This is the inside of the conduit gate operation room, where the upper part of the hydraulic cylinder (the red part) is visible. It is composed of red, yellow, and blue, as if it were a recreational facility.

View from the catwalk toward the right bank

A tiger fence has been installed for safety reasons, as children also visit the site.

View downstream from the catwalk

The Managawa Dam has a fountain downstream. It is common to see fountains in dam lakes for aeration, but downstream fountains are rare.

The water taken from the Managawa Dam is delivered to the Managawa and Gojokata power plants located several kilometers downstream, causing a section of the Managawa Gorge in front of the dam to have almost no water flow.

This fountain was constructed by the Managawa Dam Water Environment Improvement Project to solve this problem. In other words, it is a water fountain for river maintenance.

This fountain not only improves the environment, but also makes it look cool with rainbows.

Looking up at the crest gate from the center of the downstream face

You will never see an angle like this, so if you go to the tour, be sure to look up at the center of the dam. But be careful not to get dizzy and fall backwards.

Staircase in the audit corridor

We are back in the dike again.

corridor connecting an annex to a pond-side building (in traditional palatial-style architecture)

I have a very hazy memory, but I think it was the deepest place.

Photo panel exhibition by dam enthusiasts

監査廊内にはぼくらダム愛好家が撮影したダムの写真パネルが展示されています。ぼくのパネルもあるはずなのですが、なぜか写真に撮ってなくて本当にあったのかは謎です。また、この記事を書くまでに8年も経過していますので他の方々のパネルが今も展示されているかは不明です。（というか8年も経つのか…😓）

Power generation equipment for administrative use inside the maintenance and discharge building

As mentioned above, water taken from the intake for power generation is delivered to the Managawa Power Station and Gojokata Power Station downstream, but is also delivered to the maintenance and discharge building by diverging into a bypass discharge pipe on the way. The photo shows the power generation equipment for administrative use in the maintenance and discharge building. It is very compact for administrative use.

Inside the maintenance and discharge building

Inside the maintenance and discharge building, there are valves for fountain, unspecified, and maintenance flow, in addition to the valves for hydropower generation mentioned above. It is good to see that elementary school students are reading the explanatory panels properly.

Valve Group

I no longer remember which valves are which, but they are all blue.

View of the fountain and the downstream face of the levee

The fountain can also be seen up close during the tour.

Temporary drainage tunnel?

Concrete structure visible a short distance upstream from the fountain. It may be a temporary drainage tunnel during construction.

Downstream view of the levee from the left bank

We are now back at the top level. The arch dam, with its majestic wings spread out, is really wonderful.

Event site on the left bank

It may seem like a festival, but the Forest and Lake Friendship Seasonal Event is a festival for the dam.

View of the top edge from the left bank

Although automobiles are allowed to pass through, there is nothing beyond this point, so the only vehicles passing through are construction vehicles.

Selective water intake system, boat house and incline

In the foreground is the selective intake system, from which water is pumped to the aforementioned power plant and other facilities. In the back are the boatyard and the incline. The slope is quite steep.

Crestgate Unwinder Room

This is the winding machine room of the crest gate. It is built in a curve along the dike.

View of the dam lake from the top

The water level is lowered in the summer, so the soil is exposed on the lakeshore. Two structures that look like bridge piers can be seen in the center of the lake. It seems that a bridge was built here before the dam was constructed.

Managawa Dam Water Level Observatory

A water level observatory is located on the right bank side.

Oyabashira on the right bank

We have come to the right bank. The nameplate of the Managawa Dam is housed in the parent pillar, but this one is still in the Ministry of Construction. Also, if you look at the top of the abutment on the left bank, you can see the remains of the cable crane foundation.

View of the upstream face of the embankment from the right bank

The upstream face can be seen coming straight down from the top edge to around the crest gate threshold, and rounding off from there.

memorial (stone)

The cenotaph for the Managawa Dam is located on the right bank. We are grateful for the opportunity to visit the site and join hands.

Downstream view of the levee from the right bank

The right bank has a gap due to a protruding landslide, so it is like aiming at the downstream face of the embankment.

View downstream from the top

The Managawa Dam crest gate is gray, almost white, but I think it is unusual to see such a bright color.

Ministry of Land, Infrastructure, Transport and Tourism patrol car

三菱のRVRだったかな。近くにいた職員の方が「こんなの撮らなくても😓」と苦笑されてました(笑)

View of the upstream face of the embankment from the left bank

Managawa Dam in midsummer. It is time to say goodbye.

Stone monument at Lake Manahime

The Managawa River Dam has many points of interest. If you have a chance, we would like you to see the dam from inside the embankment and downstream.

statue of Mana-hime

Walk a few hundred meters upstream along the left bank of the Managawa River Dam, and you will see a golden statue. It is a statue of Princess Mana, from whom the dam lake takes its name. Princess Mana is a sad legend of a human sacrifice, but the statue stands by the lakeside as if she herself were appealing to the public about the importance of water. (The statue of Princess Mana is cured during the winter, so a visit during other seasons is recommended.)

The embankment is of course a highlight, but the Managawa Dam is also interesting to learn about episodes that prevented flooding, the legend of Princess Mana, and more. If you visit Fukui, please take a look at the Managawa Dam.

Managawa Dam Specifications

Other facilities/observations

Map around Managawa Dam

Weather around Managawa Dam

Accommodations that may be close to Managawa Dam