Date of interview: Sunday, March 24, 2013

After receiving our dam enthusiast helmets at Nanashiki Dam, we moved on to Ikehara Dam. This is also owned by Power Development and is an arch dam dedicated to power generation.

Downstream view of the levee from Route 169

Ikehara Dam does not have an overflow section on its embankment, and its flood discharge is located elsewhere.left bank (of a river)interpoint (interword separation)right bank (shore)The expressions "upstream" and "downstream" are a bit complicated. However, we will proceed as if there is a river here.

Directly below the embankment is the Kitayama Sports Park, which offers a campground, soccer and tennis courts, and other playgrounds.

Downstream view of the levee from Route 169

Downstream view of the levee from Kitayama Sports Park just below the levee

We have come to Kitayama Sports Park. You can "look up" at the non-overflow domed arch dam. There is also a stage, so I would like to do a live dam concert.

Let's get even closer to the levee.

Beyond the stage and approaching the embankment, there is an area where the earth is piled up like an earthwork, but it is unclear why it is done this way.

Fences and gates directly below

Unfortunately, once you cross that earthwork-like structure, you are blocked by a fence and cannot get any closer.

A view of the nadir

A cherry tree was planted directly below, with a few blossoms here and there.

Management Office & Observation Deck & Restrooms

Although we have reached the top level, we will visit the water intake facilities and flood discharge area first, not the levee. This cylindrical building is a combination of an unmanned control center, observation deck, and restrooms. It looks like a water wheel, but what do you think?

water intake facility

Water intake facilities for power generation. From left to right are No. 1, No. 2, No. 3, and No. 4. No. 3-4 are surface intake facilities for turbidity control during flooding.

Signboard explaining surface water intake facilities

Here is a sign explaining the surface intake facilities.

View of the upstream face of the embankment from the observation platform

You can capture the upstream face from the observation platform. It is a little hazy, but you can see that the water is firmly dammed.

Water intake facilities and flood discharge

This is a view of the intake system and flood discharge from the observation platform. The upstream face of the levee is visible at the far left, so you can see the positional relationship between the two.

Viewing platform

Next to the building where the rooftop is an observation deck is a landslide, which can be reached by crossing a small bridge, which was also open to the public as an observation deck.

Mysterious Remains

These may be the remains of the construction. You can see them at the viewpoint of Jizan.

Cenotaph and stairs to the power supply shrine

Further in, you will see the cenotaph and the stairs to the power supply shrine.

Ikehara Power Shrine

We will visit the Shrine of Power Supply. It is a small shrine, but the torii gate is made of stone and is extremely magnificent.

shrine receiving offerings of electricity

View of the upstream face of the embankment from near the power supply shrine

It is a high point to be able to see the levee from various places.

Mysterious Remains Part 2

The surrounding area is dotted with such remains. Were these also used during construction?

Mysterious Remains Part 3

I'm sure it would be different if I knew what the remains were, but I never get tired of looking at them.

Flood discharge gate pier

The roller gate of the Ikehara Dam is 15.0 m wide by 16.842 m high; to support such a huge structure, the gate piers are also huge.

View of roller gate and chute section and downstream

This is the roller gate. Since there are four such huge roller gates, the chute section is also huge. The force reducer is also a curious structure.

Looking downstream from the flood discharge

Still, it is an amazing sight. The power plant facilities can be seen below, although they are hidden by the flow-conducting wall. It is also amazing that the Kitayama River flows like a hairpin curve. However, it is a bit strange to see a hairpin of the river at the end of the flood discharge.

Normally, a dam is constructed along the flow of a river, so that the river begins again downstream from the damming. In the Ikehara Dam, however, the river crosses below the flood discharge.

Pre-construction aerial view

I thought it was strange, so I obtained aerial photos taken by the U.S. military before construction (1947/9/23, 1947) from the GSI website.

Aerial view of the Ikehara Dam area after construction

And here is an aerial view of the Ikehara Dam area after construction. Just looking at it makes my nose bleed. (Taken on 11/05/2019, the first year of 2019)

Location of flood discharge vs.

I then zoomed in on the area around the dam in the pre-construction aerial photograph. I also plotted the location of the embankment and flood discharge in comparison with the current aerial photograph. To our surprise, we found that the area downstream of the levee where Shimokitayama Sports Park is located was originally the Kitayama River.

There is a large pond at the southern end of the park, which was a remnant of the Kitayama River. Moreover, you can see that the flood discharge was installed on the mountain ridge as a shortcut to the Kitayama River.

From the west (left side of the photo), the Ikego River originally joins the Kitayama River at the southern end of Shimokitayama Sports Park, but after construction, the Kitayama River from the confluence to the flood discharge area was changed to the Ikego River, and the Kitayama River downstream from the flood discharge was redefined as the original Kitayama River.

Now I understand why the river crosses under the flood discharge. Still, it's amazing...

Downstream view of the levee from the left bank

We finally reached the dike.

View of the dam lake, intake facilities, and flood discharge from the left bank

When I think about the fact that that flood discharge was originally a mountain, I am struck by the power of human beings.

View of the top edge from the left bank

It is a very wide top end. It is open to automobile traffic and, like the Shichiro Dam, is a national road at the top end.

Nameplate of the 100 Dam Lakes

Ikehara Reservoir, the dam lake of Ikehara Dam, was recommended by Kamikitayama Village and Shimokitayama Village, and is recognized as one of the 100 best dam lakes by the Japan Water Environment Center. The nameplate has become dirty, but I need a cleaning tool for this kind of situation.

Ikehara Dam is also a mecca for bass fishing, as is Shichiro Dam, and it is said that large fish of 50 cm or more, called "lunker size," can be targeted.

View downstream from the center of the top edge

It is no longer a river, so the term "downstream" may be too subtle, but I guess it is the old lower reaches of the river. Still, it is quite wide from the fence to the levee, as seen from here.

Top railings downstream of the right bank

It is a high column with a tremendous sharp-edged design.

View of the top edge from the right bank

The right bank is also wide. Although it is deep in the mountains, tourists can be seen here and there, including anglers and families. You can also see a family in this photo.

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

The rounded embankment has an indescribable glamour.

Downstream view of the levee from the right bank

After all, the best thing about a domed arch dam is that it looks like a bird spreading its wings. It is so cool that you don't want to leave.

Bird's eye view of the location of the surrounding dams

A bird's-eye view showing the location of Sakamoto Dam (Nara), Ikehara Dam, Nanashiki Dam, and Komori Dam (Mie) was installed at the dam site. However, we were unable to visit the Sakamoto Dam this time because Route 425 is closed to traffic and we did not have enough time to visit the Komori Dam. We hope to visit again someday.

View of the levee from the right bank observatory

On the ridge on the right bank, there are cottages in Shimokitayama Sports Park, and on the way to the park, there is a place where the embankment can be seen.

Ikehara Dam is a dam with a lot to see, with its embankment and flood discharge visible from various locations. It is a mecca for bass fishing, a famous cherry blossom viewing spot, a hot spring, and a campground, making it a dam where you can play all day long.

Ikehara Dam Specifications

Location	Kamiike, Shimokitayama-mura, Yoshino-gun, Nara-ken
River Name	Shingu River system Kitayama River
Objective	P(Power generation)
Model	A(arch dam)
Bank height	111m
Bank length	460m
Dam volume	647,000m3
Watershed Area	300 km2 (direct: 277 km2, indirect: 23 km2)
Reservoir area	843ha
Total storage capacity	338,373,000m3
Effective water storage capacity	220,083,000m3
Dam operator	Power Development Co.
Main body constructor	Kumagai Gumi
Year of launch	1962
Year Completed	1964
Name of Dam Lake	Ikehara Lakeroasted or parched rice flour(in Japanese history)Ikehara Reservoirunimpeded bodily function (one of the six supernormal Buddhist powers))