Kandagawa - A River Watching Over Tokyo

The Kanda River.

It runs straight through the heart of Tokyo.

My name is James Farrer.

I study the culture of Tokyo and the history of its development.

I've lived here for more than 20 years.

When I'm walking in the city, I often cross the Kanda River.

You'll find it running between buildings and residential areas.

Back in the old days, the river was a popular subject of paintings.

I've decided to take a journey along this beloved river.

So this is the Kanda River.

There's a lot of history here, there's a lot of things I don't know.

We're going to go out to talk to people today

and introduce the history of this river.

Kandagawa – A River Watching Over Tokyo

The Kanda River runs for 24.6 kilometers starting in the west,

through the city, and into the Sumida River.

My first stop is the source of the river.

The primary source is at Inokashira Park.

It is a famous spot that every Tokyoite knows.

I've been living in this neighborhood for some years now,

but I never really thought of the pond there

as the source of the Kanda River.

This is where we used to come, right here, where all the kids would get out.

I guess I can try myself.

I haven't done this in a long time,

but all the kids would come down here on these rocks.

And usually without your shoes on, you can stand here.

And actually, there's a lot of crayfish here.

A little bit of nature in the middle of Tokyo,

which is really what this is great for.

I'm going to find out more about the source of the river right now.

Watanabe-san? Hello.

This is Watanabe Yasuhiro.

He's a member of a volunteer group that offers guided tours of the park.

I asked Watanabe-san about the source of the Kanda River,

and where the water in the pond comes from.

Let's take a closer look.

Wow, look at that.

That's a beautiful pond and there's water coming out of a stone.

It looks like the pondwater comes from a spring.

You can see it's higher over there.

Here, it's a bit lower.

When rain falls, the groundwater moves to the lower ground.

This place happens to be a natural outlet for that water.

This water is filtered by the ground.

It was very clean spring water, and with good volume.

This clean and plentiful water supply

caught the eye of shogun, Tokugawa Ieyasu.

He started the Edo shogunate in 1603.

Much of the land in the center of Edo, or old Tokyo,

was reclaimed from the sea.

If a well was dug there, only seawater came out.

Ieyasu decided to establish a supply of drinking water

by guiding the spring water from Inokashira Pond

to the middle of the city through a river.

So, the Kanda River supplied water?

Yes, Kanda River was the Kanda Josui: the water supply in the Edo period.

Watanabe-san guides me to the point where the river starts.

So this is all from the Edo period?

Yes, something like this. It was the Kanda water supply.

The Kanda River, under the oversight of the shogunate,

provided drinking water for the people of Edo.

I've decided to go downstream along the Kanda River.

Here is where the park ends.

Okay, so here it is.

This is where you can see...

they started turning this into a canalized river,

but this is the natural part over here that we all come to play in.

So, this is the leftover part that's kept the way it was.

And this is how it's going to look until all the way into the city,

this long canal.

In order to protect against flooding,

the banks of the river past Inokashira Park are all built-up like this.

Flood protection actually started in the Edo period

because of all the rivers and waterways in the city.

Kanda River was thought of as a raging river.

This is an old map of the Kanda water supply.

It's winding and has many branches.

It's easy to see how there could be mass flooding if a typhoon hit.

The flood protection along the Kanda River is still being improved.

I'm about ten kilometers downstream from Inokashira Pond now.

Okay, I think this is it.

I've been looking for a while and it's a hot day. So, look.

This is what I was looking for, I think.

This is a tunnel. An entrance to the underground waterway.

When I first moved to Japan, over 20 years ago,

there was an enormous construction site over here and I lived right on the river.

Then I learned it was for flooding.

There was going to be a big underground tunnel, or catchment,

for water from this river.

And I think this is the entrance right here.

The entrance here allows overflow from the river

to enter an underground tunnel reservoir.

I was able to get a look at that underground reservoir.

This is Mukoyama-san.

He explains how the facilities work using a model.

This is a model of the underground reservoir.

I see the water is flowing.

This shows how the river is inundated as rain keeps falling.

When the river is about to overflow,

a gate is opened, and the water goes underground.

First, the powerful flow collects in a tank about 50 meters underground,

and then it flows more slowly into the tunnel.

Next, I was taken underground.

It's cool down here.

Yes, it's 14 degrees Celsius year-round.

After passing a heavy door that prevents water from getting out,

I arrived at the underground reservoir.

Wow, look at this.

This is the underground reservoir.

Underneath the road, where I used to live

when I first came to Tokyo is a giant, giant tunnel.

I never would've known that this thing existed.

It took them years to build. It's amazing.

It's 4.5 kilometers long.

Five hundred and forty million liters of water can be stored here.

So this is where all the water goes during those huge typhoons.

It's like something built out by a giant,

giant sandworm in Dune or something like that.

Can you tell me why such a giant facility was made?

In the late 1950s, there was a lot of development in the Kanda River basin.

Over 90% of the area has been developed.

With all the homes, buildings, roads-

rain no longer drains into the earth.

As the city urbanized,

flooding became more frequent in the Kanda River basin.

In the late 80s, construction for this reservoir began.

And expansions are still underway.

Has this ever filled up?

It happened once in 2013 during a typhoon.

The whole 540-million-liter capacity was used up.

But no major flooding occurred.

That's great. So it's been useful.

Yes, very useful.

No matter what decade we're in,

flood prevention is a key concern for Tokyo.

If we follow the Kanda River further downstream,

we see that it joins two other rivers,

Zenpukuji River and Myoshoji River.

Water from the Myoshoji River runs into the Kanda River here.

After the rivers join,

the volume of water is almost incomparable to before.

A five-minute walk from that point,

I come across an interesting workshop.

I knew there were dyeing factories here in the old days,

but it looks like there's a museum for dyeing here.

It's still a factory or workshop.

Let's go take a look.

Hello there. My name is Farrer.

This is the fifth generation owner of the workshop, Tomita-san.

It started back in 1914.

This workshop continues to produce

traditional dyed fabric with designs from the Edo period.

This is a treasure ship design.

I see.

So when you wear it, treasure is brought to you.

So it has a meaning. Interesting.

The fabric is dyed using traditional stencils.

An artisan carves these by hand.

Tomita-san says a single stencil costs around 4,000 dollars.

I was shown the dyeing process.

This is Asano-san who's been doing this for 60 years.

The stencil is placed on the fabric, and glue is applied over it.

Next, dye is applied.

The parts with the glue don't get dyed, forming a white pattern.

The fabric is steamed to bring out the color and set the dye.

Finally, the glue is washed out,

and the dyed fabric is complete.

The fabric used to be washed in the river.

It's similar, but the flow of the river would wash the glue off for you.

Here I must shake it. It's hard work! Makes my back sore.

So this workshop used to wash the glue out in the Kanda River.

Now, it's done using well water.

But it makes you wonder, wasn't the Kanda River for drinking water?

Was it okay to use it in the dyeing process?

It was called the Kanda water supply,

but by the time this workshop started in 1914, it was a normal river.

Wastewater ran into it.

In the late 19th century,

the Kanda water supply quickly became polluted.

The government had changed,

and it wasn't maintaining the water supply like the shogunate had.

So, the new government decided to adopt a Western-style piping system.

In 1898, a modern water purification plant was built.

A few years later, and the Kanda River was no longer the water supply.

After the Kanda River ceased to be the water supply,

many dye workshops opened along the river.

The strong flow was sure to be of use.

At the peak, there were probably around 300 artisans here.

We were the largest workshop. There were about that many in Tokyo.

How many are there now?

They're almost gone. It's tough work.

The Kanda River went from being the water supply

to helping a traditional Edo craft flourish and live on to this day.

Next is a place where the former Kanda Josui water supply

was diverted into a waterway.

It's now a park.

Looking at the map, this is about the spot

where the Kanda Josui separated itself

from this artificial canal over here.

And then the rest of the water would have flowed down through here I guess.

So there should be a spot somewhere around

where we can see where the actual Kanda Josui would go off

to provide drinking water for the city.

Right up here somewhere

so we can go take a look over there and see where it is.

Maybe up here?

Okay.

It looks like they've created a kind of old model

of where the old Josui was right here in this area.

This would have been where it flowed in the old days

right down through here, I guess.

And down that way, towards the place

where people could then get the water into the city.

Maybe we can walk down here and take a look and see

a little bit better what it looks like, how far it goes.

It looks like there's some sort of dam.

The water just stopped right here by this rock

and I don't really know what that means but let's go take a look.

There looks to be some sort of explanation up here.

Oh, okay. So, according to this explanation,

this gate here, this is an original gate.

An original stone lock.

There was a wooden panel that you could open and close

to control the flow of the water.

The gate could interrupt the flow of the Kanda Josui,

raising the water levels, and divert water for drinking.

It could also let excess water back into the river.

The water being interrupted by the gate looked like a waterfall.

It became a famous sight in Edo.

This stone lock was part of the gate.

The diverted water flowed in a stone aqueduct instead of a river.

This canal stretched for about five kilometers on a gentle slope,

bringing water into the city.

Next, I head for another famous spot along the Kanda River.

Here it is.

Let's see... Oh, okay!

So, this is the spot where the aqueduct

would actually cross over to the other side of the Kanda River.

The aqueduct actually came out from under here

to go to the other side of the river

because it was coming out from under the ground.

This is where it was.

The Kanda Josui aqueduct crossed the Kanda River itself here.

Many people came to see the aqueduct span the river valley.

Edo drinking water crossed over here

and entered the underground water supply in the city.

But how did the people of Edo actually receive their water?

I decided to go to the nearby waterworks museum

to learn about the Edo period aqueducts.

There were these conduits under the houses.

Huh, it was all made of wood?

Yes, mostly wood in the Edo period.

Wooden conduits were put underground

to carry the water throughout the city.

These underground conduits connected to tanks,

which provided an important function.

The water flowed using slopes.

The conduits were slanted to make the water flow into the tanks.

As the water level in the tanks rose,

the water would flow into the next conduit.

With enough water pressure to keep the water in the tanks at the same level,

the water would consistently flow.

The people of Edo would then draw water from a well.

What an ingenious system.

It's said that people born and raised in Edo

were proud to have their first bath as a newborn

with water from the waterworks.

I've heard France and Germany had rather developed systems,

but I think Edo's was particularly comprehensive.

It was the biggest by far in Japan. And it was maintained for centuries.

That's pretty impressive.

From Inokashira Pond all the way to the waterworks...

I think I'm finally grasping the whole picture.

There's only a bit left on my journey along the Kanda River.

It's time to leave the water supply and head downstream.

From Iidabashi, on the north side of Edo Castle,

I'm heading along a five-kilometer stretch

that connects to the Sumida River.

James, we just passed under Suidobashi Bridge.

"Suido" means waterworks: that's how important it was to Edo.

This is Hirayama-san.

He's been coasting along Tokyo's waterways for over ten years,

mastering their history.

This place used to be called Kanda Hills. It was highland.

But it was dug up and turned into this canal.

The local domain was ordered by the shogunate to do it.

It was what we'd now call a public works project.

Apparently, this area used to be a highland.

But the river that passed through here was close to Edo Castle,

and it frequently overflowed.

In order to protect the castle from flooding,

the river was diverted into the Sumida River.

The Tokugawa shogunate also wanted to guard Edo Castle from attack,

so by turning the highland into a river,

they were able to create a moat.

It looks like a natural green valley

where you're going down through a river,

but in fact, this is all a man-made river

that is pushed through the middle of what was in fact,

a hill or a mountain called the Kanda Mountain.

When you ride through the city on the train,

you look down on it and you just barely notice it.

But down here, it really looks magnificent.

It looks like a little green sort of a quiet country valley in a way.

You can see how deep it is

and how difficult it would've been to cross this

with an army or with anything in the old days.

It looked like a natural extension of the river,

but it was actually intended to act as a moat for Edo Castle.

What's this old brick building here?

This used to be a train station. A grand one, like Tokyo Station.

This was Manseibashi Station.

It had the same architect as Tokyo Station.

Actually, this station probably had more riders.

It was a bustling terminal near the current Akihabara Station.

Around here, there was a lively produce market

that continued for 270 years from the Edo period.

The Kanda River was used to bring in fresh produce

that you wouldn't see anywhere else.

The river was vital to transportation, and it helped Edo flourish.

I'm finally getting close to the mouth of the river.

A lot of old cruise boats are here.

A classic Edo scene.

The Kanda River has had a winding journey throughout the ages.

But it's still going strong.

It's intertwined with so many people and with so much history.

I'm looking forward to seeing what's around the next bend.