Irrigation: ditches, canals and drains

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Irrigation: ditches, canals and drains

Joseph Eisenberg
It looks like our long discussion a while back didn't lead to
substantial changed to the wiki pages for waterway=drain,
waterway=ditch and waterway=canal.

I was checking on how many waterway=ditch were tagged as being used
for irrigation, and decided to slightly updated the pages. I've marked
all features as "De facto", and slightly adjusted the descriptions and
pages to suggest that:

- A waterway=drain is lined by concrete or similar materials and is
used to remove superfluous water
- A waterway=ditch is not lined and is usually used for drainage, but
can (controversially) be used for irrigation.

I note that the page suggested irrigation=yes, but actually there are
4 options to showing that a ditch or canal is used for irrigation:

1) irrigation=yes was the first tag used, starting it 2011. As of May
2019, it has been used 200 times with canals and 2000 times with
ditches. Most of these tags were added between 2011 and 2013.

2) service=irrigation was used starting in 2012, and as of May 2019 is
used 12,000 times, mainly with canals but also with several hundred
ditches

3) usage=irrigation was introduced in 2018 and usage is increasing
quickly. It is currently used 6,000 times.

4) About 2000 hundred canals are tagged canal=irrigation and a few
ditches are tagged ditch=irrigation or irrigation=ditch

The tagging suggests that waterway=canal is more commonly used for
irrigation features, but there certainly is significant usage of
waterway=ditch for irrigation:

overpass-turbo.eu finds 3605 ways tagged waterway=ditch plus one of
the irrigation related tags: https://overpass-turbo.eu/s/JqW

Comparisions: 10687 ways tagged waterway=canal and one of the
irrigation tags: https://overpass-turbo.eu/s/JqX

Waterway=drain is  specified for irrigation on 1298 ways:
https://overpass-turbo.eu/s/JqY

So it looks like a number of mappers consider waterway=ditch
appropriate for use with irrigation features, and there is even some
use of waterway=drain for irrigation, which surprises me.

What, then, should be the distinguishing characteristic between
waterway=canal and waterway=ditch or =drain? Width or importance or
navigability, or should we still mention the usage as the main
difference?

- Joseph E

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Re: Irrigation: ditches, canals and drains

dieterdreist


sent from a phone

> On 29. May 2019, at 03:37, Joseph Eisenberg <[hidden email]> wrote:
>
> What, then, should be the distinguishing characteristic between
> waterway=canal and waterway=ditch or =drain? Width or importance or
> navigability, or should we still mention the usage as the main
> difference?


IIRR ditches were seen without construction like steel or concrete, just a man made depression to channel water, while drains are required to have their borders (and maybe base) constructed.

Not sure about small rock-cut waterways  with massive impermeable sides, are these ditches or canals or drains?

Stating the usage explicitly might help interpretation of the data, or while we’re still mapping fragments of an incomplete network, although I would have guessed with a more mature mapping this could already be seen from looking at the network structure and flow directions?

What about the practical, human scale distinction we use for natural waterways (can be jumped over), wouldn’t it be equally interesting for man made waterways?
Is a canal you can jump over still a canal, or does size somehow come into the equation? Can there be draining canals, or are these always drains?

Cheers, Martin
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Re: Irrigation: ditches, canals and drains

Joseph Eisenberg
> Not sure about small rock-cut waterways  with massive impermeable sides, are these ditches or canals or drains?

We don't have these in the western USA, but generally our ditches are
dug out of the soil, so I would be surprised to see a feature tagged
as waterway=ditch if it were cut from bedrock or lined with stone.

I'd think waterway=canal would be appropriate for these if they are
large enough.

One tag that's already used is canal=qanat for "a gently sloping
underground channel or tunnel constructed to lead water from the
interior of a hill to a village below", found in the Middle East

If there are small irrigation waterways that area lined with stone (or
concrete etc), we probably need a new tag, since waterway=drain is
pretty strongly associated with drainage, not irrigation, and
waterway=canal probably has a minimum width?


On 5/29/19, Martin Koppenhoefer <[hidden email]> wrote:

>
>
> sent from a phone
>
>> On 29. May 2019, at 03:37, Joseph Eisenberg <[hidden email]>
>> wrote:
>>
>> What, then, should be the distinguishing characteristic between
>> waterway=canal and waterway=ditch or =drain? Width or importance or
>> navigability, or should we still mention the usage as the main
>> difference?
>
>
> IIRR ditches were seen without construction like steel or concrete, just a
> man made depression to channel water, while drains are required to have
> their borders (and maybe base) constructed.
>
> Not sure about small rock-cut waterways  with massive impermeable sides, are
> these ditches or canals or drains?
>
> Stating the usage explicitly might help interpretation of the data, or while
> we’re still mapping fragments of an incomplete network, although I would
> have guessed with a more mature mapping this could already be seen from
> looking at the network structure and flow directions?
>
> What about the practical, human scale distinction we use for natural
> waterways (can be jumped over), wouldn’t it be equally interesting for man
> made waterways?
> Is a canal you can jump over still a canal, or does size somehow come into
> the equation? Can there be draining canals, or are these always drains?
>
> Cheers, Martin
> _______________________________________________
> Tagging mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/tagging
>

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Re: Irrigation: ditches, canals and drains

dieterdreist


sent from a phone

On 29. May 2019, at 12:53, Joseph Eisenberg <[hidden email]> wrote:

If there are small irrigation waterways that area lined with stone (or
concrete etc), we probably need a new tag, since waterway=drain is
pretty strongly associated with drainage, not irrigation, and
waterway=canal probably has a minimum width?



maybe these could be called aqueducts?


Cheers, Martin 



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Re: Irrigation: ditches, canals and drains

Joseph Eisenberg
In reply to this post by Joseph Eisenberg
Which of the ways of tagging "irrigation" should be used?

"irrigation=yes" works ok, but it hasn't been very popular the last few years
"service=irrigation" is still most common, but the key is a little odd
"usage=irrigation" makes sense and is increasing in usage

See chart of usage over time:
https://wiki.openstreetmap.org/wiki/Tag:usage%3Dirrigation#Alternative_tagging

I think "usage=irrigation" may be the best option.

On 5/29/19, Joseph Eisenberg <[hidden email]> wrote:

>> Not sure about small rock-cut waterways  with massive impermeable sides,
>> are these ditches or canals or drains?
>
> We don't have these in the western USA, but generally our ditches are
> dug out of the soil, so I would be surprised to see a feature tagged
> as waterway=ditch if it were cut from bedrock or lined with stone.
>
> I'd think waterway=canal would be appropriate for these if they are
> large enough.
>
> One tag that's already used is canal=qanat for "a gently sloping
> underground channel or tunnel constructed to lead water from the
> interior of a hill to a village below", found in the Middle East
>
> If there are small irrigation waterways that area lined with stone (or
> concrete etc), we probably need a new tag, since waterway=drain is
> pretty strongly associated with drainage, not irrigation, and
> waterway=canal probably has a minimum width?
>
>
> On 5/29/19, Martin Koppenhoefer <[hidden email]> wrote:
>>
>>
>> sent from a phone
>>
>>> On 29. May 2019, at 03:37, Joseph Eisenberg <[hidden email]>
>>> wrote:
>>>
>>> What, then, should be the distinguishing characteristic between
>>> waterway=canal and waterway=ditch or =drain? Width or importance or
>>> navigability, or should we still mention the usage as the main
>>> difference?
>>
>>
>> IIRR ditches were seen without construction like steel or concrete, just
>> a
>> man made depression to channel water, while drains are required to have
>> their borders (and maybe base) constructed.
>>
>> Not sure about small rock-cut waterways  with massive impermeable sides,
>> are
>> these ditches or canals or drains?
>>
>> Stating the usage explicitly might help interpretation of the data, or
>> while
>> we’re still mapping fragments of an incomplete network, although I would
>> have guessed with a more mature mapping this could already be seen from
>> looking at the network structure and flow directions?
>>
>> What about the practical, human scale distinction we use for natural
>> waterways (can be jumped over), wouldn’t it be equally interesting for
>> man
>> made waterways?
>> Is a canal you can jump over still a canal, or does size somehow come
>> into
>> the equation? Can there be draining canals, or are these always drains?
>>
>> Cheers, Martin
>> _______________________________________________
>> Tagging mailing list
>> [hidden email]
>> https://lists.openstreetmap.org/listinfo/tagging
>>
>

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Re: Irrigation: ditches, canals and drains

Mateusz Konieczny-3
For me all of the look equally fine.


29 May 2019, 15:24 by [hidden email]:
Which of the ways of tagging "irrigation" should be used?

"irrigation=yes" works ok, but it hasn't been very popular the last few years
"service=irrigation" is still most common, but the key is a little odd
"usage=irrigation" makes sense and is increasing in usage

See chart of usage over time:
https://wiki.openstreetmap.org/wiki/Tag:usage%3Dirrigation#Alternative_tagging

I think "usage=irrigation" may be the best option.

On 5/29/19, Joseph Eisenberg <[hidden email]> wrote:
Not sure about small rock-cut waterways with massive impermeable sides,
are these ditches or canals or drains?

We don't have these in the western USA, but generally our ditches are
dug out of the soil, so I would be surprised to see a feature tagged
as waterway=ditch if it were cut from bedrock or lined with stone.

I'd think waterway=canal would be appropriate for these if they are
large enough.

One tag that's already used is canal=qanat for "a gently sloping
underground channel or tunnel constructed to lead water from the
interior of a hill to a village below", found in the Middle East

If there are small irrigation waterways that area lined with stone (or
concrete etc), we probably need a new tag, since waterway=drain is
pretty strongly associated with drainage, not irrigation, and
waterway=canal probably has a minimum width?


On 5/29/19, Martin Koppenhoefer <[hidden email]> wrote:


sent from a phone
On 29. May 2019, at 03:37, Joseph Eisenberg <[hidden email]>
wrote:

What, then, should be the distinguishing characteristic between
waterway=canal and waterway=ditch or =drain? Width or importance or
navigability, or should we still mention the usage as the main
difference?


IIRR ditches were seen without construction like steel or concrete, just
a
man made depression to channel water, while drains are required to have
their borders (and maybe base) constructed.

Not sure about small rock-cut waterways with massive impermeable sides,
are
these ditches or canals or drains?

Stating the usage explicitly might help interpretation of the data, or
while
we’re still mapping fragments of an incomplete network, although I would
have guessed with a more mature mapping this could already be seen from
looking at the network structure and flow directions?

What about the practical, human scale distinction we use for natural
waterways (can be jumped over), wouldn’t it be equally interesting for
man
made waterways?
Is a canal you can jump over still a canal, or does size somehow come
into
the equation? Can there be draining canals, or are these always drains?

Cheers, Martin
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https://lists.openstreetmap.org/listinfo/tagging


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Re: Irrigation: ditches, canals and drains

François Lacombe-2
In reply to this post by dieterdreist
Hi

Le mer. 29 mai 2019 à 10:59, Martin Koppenhoefer <[hidden email]> a écrit :

What about the practical, human scale distinction we use for natural waterways (can be jumped over), wouldn’t it be equally interesting for man made waterways?
Is a canal you can jump over still a canal, or does size somehow come into the equation? Can there be draining canals, or are these always drains?

I think that distinction between canal and drain is well established (useful vs superflous water) and understandable for common mappers.
waterway=ditch should be discouraged since distinction between drain and ditches comes with their shape and lining. Another key like structure=* would be suitable

Whatever the conclusion of this thread will be, the table here should be carefully updated

Le mer. 29 mai 2019 à 12:55, Joseph Eisenberg <[hidden email]> a écrit :
waterway=canal probably has a minimum width?
As useful water can run in ducts of any width, I don't think so.

Le mer. 29 mai 2019 à 15:15, Martin Koppenhoefer <[hidden email]> a écrit :

Is it possible to introduce waterway=aqueduct for any man made waterway and replace waterway=drain by waterway=aqueduct + usage=drainage ?

Le mer. 29 mai 2019 à 21:55, Mateusz Konieczny <[hidden email]> a écrit :
For me all of the look equally fine.

According to past discussions about yes/no values, it seems some people won't agree at least for irrigation=yes

To me service=irrigation sounds more like a paid subscription for a given performance.

+1 with Joseph for usage=irrigation

All the best

François
 

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Re: Irrigation: ditches, canals and drains

Tagging mailing list
In reply to this post by Joseph Eisenberg


Javbw

> On May 29, 2019, at 10:37 AM, Joseph Eisenberg <[hidden email]> wrote:
>
> What, then, should be the distinguishing characteristic between
> waterway=canal and waterway=ditch or =drain? Width or importance or
> navigability, or should we still mention the usage as the main
> difference?

The biggest issue - by far - is conflating construction with purpose. This makes the tags ambiguous. We can invent a definition, but the ambiguity will remain because of our tag value choices, as we have to be careful to manage "purpose".

Canal implies construction and purposes. (Many varying purposes).

Drain implies a purpose

Ditch implies construction.

Canals move things from place to place. aquaducts usually exist to move water from one large water body (a lake or river) to another (a holding lake or another river). They are very large (no less than 1 meter, perhaps, usually more)

Drains take away waste. We have added "construction" to the definition: "they are lined - concrete or steel or whatever"

Ditches are dug into existing ground.

In some places, irrigation is separate from storm water management. A storm drain takes wastewater to a river. An irrigation ditch moves water from a supply to a field for orange trees to soak it up. These simple definions work well enough for Southern Califorina.

But the Purpose becomes muddied in some places when they are linked together. Here in Japan, we probably have 4x the length of drains than roads. It is immense. They are in every street and and every rural area. They channel rainwater across the land for farming. The "storm drain" system is the irrigation system. One Field's runnoff is the next Field's supply. Drains run from small weirs in streams and canals. These cast concrete drains surround each group of fields. The drains feed ditches which flood the fields and *go back* into the same  drains which *feed* the next set of ditches. They are cross connected everywhere, like a spiderweb. Farmers turn them off with large sluices, little sliding gates, and dirt mounds to control how and when fields flood. They have thousands of tiny resivoirs the size of a backyard pool scattered everywhere. The help collect rain and balance distribution load for irrigation.

Irrigation canals - aquaducts - are quite rare. Every town has one or two. They move water from one water body to the next, balancing the supply in an area (the California aquaduct is huge and manages the supply for California), but only one aquaduct I Know of is larger than 1 meter).

Drains collect and/or distribute water in man-made structures to/from larger ones (rivers, streams, lakes etc)

Ditches collect and/or distribute water in ditches carved into the ground, with little to no improvement.

Adding purpose via an additional tag (like canal does) is the only way to make sense of it. (and "both waste and irrigation" must be an option).

Javbw

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Re: Irrigation: ditches, canals and drains

Joseph Eisenberg
In reply to this post by dieterdreist
I had a chance to look at these 4 examples of small artificial
waterways used for irrigation or drinking water and lined with stone
or concrete, suggested to be tagged as <waterway?>=aqueduct

1) This is a shallow, straight waterway about 1 meter wide, which is
the bottom of a wider depression, in a semi-arid region. The bottom is
curved, but lined with concrete perhaps, and it's being used to water
sheep. This might be called a "canal" based on construction, or maybe
a "drain" - although I don't know the context, so I can't see if this
is mainly irrigation water or mainly drainage.

I don't think "aqueduct" would work, since it isn't above ground level:
https://assets.weforum.org/editor/skgMAyNg8Xu_anqQbTcTo87HkYgWEiN0eF-5dlsLhCo.jpg


2) This waterway looks to be about 1 to 1.5 meters wide. It's profile
is square, and the bottom appears to be at ground level and it's
probably concrete while the sides are concrete walls which rise up
about 0.5 to 1 meter above ground level. I can't tell if it's used for
irrigation or for drainage, but I suspect it's for irrigation.

I agree that this is probably best described as an "aqueduct":
http://www0.f1online.de/preW/004754000/4754656.jpg

3) A narrow waterway with stone or concrete walls on each side, in an
arid region. In the middle it is elevated on a viaduct (or bridge)
over a gully. This is probably an aqueduct used to supply drinking
water and irrigation water: >
http://www.insel-teneriffa.de/bilder-images/wasserversorgung-teneriffa-tf00_1474.jpg

4) A levada; a small channel (less than 1 meter wide and 1 meter high)
along a hillside, lined with a wall on the lower side and perhaps a
small stone retaining wall on the uphill side:
https://en.wikipedia.org/wiki/Levada "A levada is an irrigation
channel or aqueduct specific to the Portuguese Atlantic region of
Madeira."
I agree that waterway=aqueduct could be a good description for this
https://c7.alamy.com/compde/eetk3t/levada-bewasserungskanal-und-wanderweg-in-der-nahe-von-rabacal-madeira-eetk3t.jpg

The tag historic=aqueduct is already in use for historic features,
such as old roman aqueducts, which may no longer be in use, and
bridge=aqueduct is used for any viaduct or bridge that carries a
waterway above ground level, including aqueducts, irrigations canals,
and navigable canals.

It looks like waterway=aqueduct could be used for waterways that are
generally built with an above-ground structure on one or both sides,
such as stone, brickwork, concrete walls or even wood walls. This
would also include flumes and sluices. They could also be covered, but
are not a man_made=pipeline. Generally such structures are usually
narrower than a large canal, though there would be some overlap, and
are used to supply useful water, rather than to drain it like a
waterway=drain.

Most modern aqueducts used to supply water to cities in developed
countries are constructed from pipelines now, but it appears that
these older styles of aqueducts are still common in places where they
were built before the development of modern pipelines, or where local
labor and materials are still much cheaper than imported pipe
sections.

- Joseph

On 5/29/19, Martin Koppenhoefer <[hidden email]> wrote:

>
>
> sent from a phone
>
>> On 29. May 2019, at 12:53, Joseph Eisenberg <[hidden email]>
>> wrote:
>>
>> If there are small irrigation waterways that area lined with stone (or
>> concrete etc), we probably need a new tag, since waterway=drain is
>> pretty strongly associated with drainage, not irrigation, and
>> waterway=canal probably has a minimum width?
>
>
> examples
> https://assets.weforum.org/editor/skgMAyNg8Xu_anqQbTcTo87HkYgWEiN0eF-5dlsLhCo.jpg
> http://www0.f1online.de/preW/004754000/4754656.jpg
> http://www.insel-teneriffa.de/bilder-images/wasserversorgung-teneriffa-tf00_1474.jpg
> https://c7.alamy.com/compde/eetk3t/levada-bewasserungskanal-und-wanderweg-in-der-nahe-von-rabacal-madeira-eetk3t.jpg
>
> maybe these could be called aqueducts?
>
>
> Cheers, Martin

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Re: Irrigation: ditches, canals and drains

Joseph Eisenberg
In reply to this post by Tagging mailing list
Thank you for the information about Japan.

How are the small drainage/irrigation channels tagged currently in Japan?

Are most tagged as waterway=drain, waterway=canal or waterway=ditch?

We have lots of these in Indonesia, in the rice-growing areas with
irrigated fields, but most are more like deep ditches, dug directly
into the ground and unlined. Only the larger ones have been lined with
stone or concrete.

> the California aquaduct is huge and manages the supply for California

It's tagged as a waterway=canal over most of it's stretch, and I
believe this is correct:
https://www.openstreetmap.org/search?query=%22California%20Aqueduct%22#map=7/36.344/-120.167

There are a couple short sections of pipeline where the water is
pumped uphill as well.

> Adding purpose via an additional tag is the only way to make sense of it.
> (and "both waste and irrigation" must be an option).

We could consider a tag like "usage=drainage", in addition to "usage=irrigation"
This could be combined as "usage=irrigation;drainage"?

Joseph

On 5/30/19, John Willis via Tagging <[hidden email]> wrote:

>
>
> Javbw
>
>> On May 29, 2019, at 10:37 AM, Joseph Eisenberg
>> <[hidden email]> wrote:
>>
>> What, then, should be the distinguishing characteristic between
>> waterway=canal and waterway=ditch or =drain? Width or importance or
>> navigability, or should we still mention the usage as the main
>> difference?
>
> The biggest issue - by far - is conflating construction with purpose. This
> makes the tags ambiguous. We can invent a definition, but the ambiguity will
> remain because of our tag value choices, as we have to be careful to manage
> "purpose".
>
> Canal implies construction and purposes. (Many varying purposes).
>
> Drain implies a purpose
>
> Ditch implies construction.
>
> Canals move things from place to place. aquaducts usually exist to move
> water from one large water body (a lake or river) to another (a holding lake
> or another river). They are very large (no less than 1 meter, perhaps,
> usually more)
>
> Drains take away waste. We have added "construction" to the definition:
> "they are lined - concrete or steel or whatever"
>
> Ditches are dug into existing ground.
>
> In some places, irrigation is separate from storm water management. A storm
> drain takes wastewater to a river. An irrigation ditch moves water from a
> supply to a field for orange trees to soak it up. These simple definions
> work well enough for Southern Califorina.
>
> But the Purpose becomes muddied in some places when they are linked
> together. Here in Japan, we probably have 4x the length of drains than
> roads. It is immense. They are in every street and and every rural area.
> They channel rainwater across the land for farming. The "storm drain" system
> is the irrigation system. One Field's runnoff is the next Field's supply.
> Drains run from small weirs in streams and canals. These cast concrete
> drains surround each group of fields. The drains feed ditches which flood
> the fields and *go back* into the same  drains which *feed* the next set of
> ditches. They are cross connected everywhere, like a spiderweb. Farmers turn
> them off with large sluices, little sliding gates, and dirt mounds to
> control how and when fields flood. They have thousands of tiny resivoirs the
> size of a backyard pool scattered everywhere. The help collect rain and
> balance distribution load for irrigation.
>
> Irrigation canals - aquaducts - are quite rare. Every town has one or two.
> They move water from one water body to the next, balancing the supply in an
> area (the California aquaduct is huge and manages the supply for
> California), but only one aquaduct I Know of is larger than 1 meter).
>
> Drains collect and/or distribute water in man-made structures to/from larger
> ones (rivers, streams, lakes etc)
>
> Ditches collect and/or distribute water in ditches carved into the ground,
> with little to no improvement.
>
> Adding purpose via an additional tag (like canal does) is the only way to
> make sense of it. (and "both waste and irrigation" must be an option).
>
> Javbw
>
> _______________________________________________
> Tagging mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/tagging
>

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Re: Irrigation: ditches, canals and drains

Andrew Davidson-3
In reply to this post by Joseph Eisenberg
On Wed, May 29, 2019 at 11:38 AM Joseph Eisenberg <[hidden email]> wrote:
What, then, should be the distinguishing characteristic between
waterway=canal and waterway=ditch or =drain? Width or importance or
navigability, or should we still mention the usage as the main
difference?

Don't know. What I would like is some sort of tagging so I can map small and large artificial open channels. In the same way that river and stream lets me map small and large natural open channels. 

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Re: Irrigation: ditches, canals and drains

Tagging mailing list
In reply to this post by Joseph Eisenberg


On May 30, 2019, at 9:03 AM, Joseph Eisenberg <[hidden email]> wrote:

How are the small drainage/irrigation channels tagged currently in Japan?

Are most tagged as waterway=drain, waterway=canal or waterway=ditch?


they are used for different purposes. based on purpose and construction.  I use all three when mapping. (along with many many weirs &  sluice_gates).  



people tag them as streams, drains, and ditches. many streams are re-routed into new (straight) channelized systems, removing them from the old path. 

aqueducts are usually tagged as waterway=canal canal=irrigation. 

Here is a drain that pulls off of a stream and supplies water to some rice fields and then dumps back into the river less than 1 KM downstream. 

you can see how stuff is commonly tagged. I assume there are some errors. 


most rice fields are divided into long rectangles, and nominally are separated alternately by access road (alley) and a ditch. 

here is a picture of the 30-40cm drains that run along most roads to supply and collect water for the fields. 




These are almost all prefabricated concrete, from 1m2 to 30cm2. 

the drains have small little plastic doors (metal wood, or a plastic soda bottle jammed in there) that feed fields directly or feed the old ditch system (1m- 50cm ditches) 


here is a large ditch that enters from the right, goes in a culvert under the road and into a concrete distribution box with a wooden weir board inside to control the water height.

 The yellow bag is controlling the flow from the box into that field set. It then continues on as a ditch towards camera. 



the lower fields then feed their water back into the ditches and drains and the drains continue on to the next set and eventually back to the source they were pulled out of (from the weir) 

it might seem unnecessary to have them re-connect to the river further downstream (often with a sluice gate through a levee), but this system absorbs all of the rain and acts as a flooding buffer, and has to empty back out into the river eventually. 

they can divert some water into holding ponds for the three weeks in summer when it is really hot and doesn't rain. 


These same drains, in suburban areas, pass through neighborhoods to go from field to field. 

aqueducts move water from river to river to keep the supply equalized or to supply water treatment plants. 

One aqaduct pulls water from a giant river about 20KM from my house to a holding lake just above my house. it then feeds water into this stream to take care of farmers down stream. 

 here is quick look at one of these aqueducts (it goes above and underground). 

https://www.openstreetmap.org/node/3123867846 node where disappears underground in the below pictures. 



here is the beginning to an (old) aquaduct near Nikko 



here is an aquaduct that goes under a huge river in Nagano. 
it has bridges over rivers and water control gates and flow control waterways it crosses.
it feeds agricultural water to Wasabi farms, which need very clean and controlled water. 
it grows in ditches that feed water into the riverbed gravel it grows in. 


Javbw


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Re: Irrigation: ditches, canals and drains

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In reply to this post by Joseph Eisenberg


> On May 30, 2019, at 9:03 AM, Joseph Eisenberg <[hidden email]> wrote:
>
> We have lots of these in Indonesia, in the rice-growing areas with
> irrigated fields, but most are more like deep ditches, dug directly
> into the ground and unlined


I imagine ~100 years ago, it was just like that in Japan. you can find sections of that old ditch system still. There are pretty big ditches that still handle supply for a very large field set.

Japan spent an insane amount of money to turn all their large & small ditches into interconnected concrete drains, added sluice gates & weirs to all the streams, built levees around all the rivers, and dug aqueducts to balance the river flows (for irrigation). I have cycled ~600Km of riverbanks and rice fields, from very remote areas down into major cities. It doesn’t really vary - it is all built to the same standard. They are widening the levees in my area after a breach elsewhere in 2015. they are always working on the water management system.

Most farming access roads were paved and now maintained as public roads that would otherwise be mud or gravel tracks in the rest of Asia. there are a lot of tracks, but a lot of “alleys” as well. this is another side-effect of Japan having spent so much money to pave and upgrade the quality of so many roads in rural areas. (rather than being merely grade 1 or 2 tracks).

I grew up in Southern California, and most roads have little-to-no drainage of any kind - rain is so uncommon. ditches, drains, and other water management features are sparse. The freeways flood in a rainstorm. living in rural/suburban Japan, I marvel at the drainage system they built for even the smallest set of fields, and the culverts under almost every single road intersection in Japan, no matter how small and remote. This irrigation/rain management system is as pervasive as the water/sewer/power/telecom services - perhaps more so.

This requires expanded levels of tagging, similar to how we have for roads, because the scale and complexity of the system (that is mappable from imagery) is far greater than what you would find elsewhere.  

This means there is room for aquaducts, drains and ditches, even if it might seem unnecessarily detailed.



I will try to take some pictures this weekend of different irrigation features to help define the tagging.


Javbw
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Re: Irrigation: ditches, canals and drains

François Lacombe-2
In reply to this post by Joseph Eisenberg
Le jeu. 30 mai 2019 à 01:55, Joseph Eisenberg <[hidden email]> a écrit :
I don't think "aqueduct" would work, since it isn't above ground level:
https://assets.weforum.org/editor/skgMAyNg8Xu_anqQbTcTo87HkYgWEiN0eF-5dlsLhCo.jpg

Why does aqueduct have to be above ground level?
Major aqueducts feeding Paris in drinkable water are underground, so do NYC ones.
 
It looks like waterway=aqueduct could be used for waterways that are
generally built with an above-ground structure on one or both sides,

As John said, it is confusing structure and purpose.
I don't see why waterway=* have to reflect the structure it is runing in.
I would add waterway=pressurised isn't necessarily for the structure (it can involve both tunnel, pipeline and caves) but for the pressure of the water.
 
Most modern aqueducts used to supply water to cities in developed
countries are constructed from pipelines now,

No, there are tunnels too
It's time to pay tribute to John McClane :

All the best

François

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Re: Irrigation: ditches, canals and drains

Mateusz Konieczny-3
30 May 2019, 15:00 by [hidden email]:
Why does aqueduct have to be above ground level?
Maybe because one of main meanings of this word is
"bridge to convey water over an obstacle, such as a ravine or valley"?

I was initially really confused by usage of aqueduct not referring to
(despite that even Roman aqueducts were mostly underground)

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Re: Irrigation: ditches, canals and drains

dieterdreist


Am Do., 30. Mai 2019 um 16:03 Uhr schrieb Mateusz Konieczny <[hidden email]>:
30 May 2019, 15:00 by [hidden email]:
Why does aqueduct have to be above ground level?
Maybe because one of main meanings of this word is
"bridge to convey water over an obstacle, such as a ravine or valley"?


the meaning of the term "aqueduct" is "leading water". Usually bridges are only constructed where they are needed, while an aqueduct will be continuous from its start to the endpoint, not just the bridges where valleys have to be crossed.

As far as I have seen the term is used for both, pressurized water conduits (tubes) and freeflowing, which makes it less suitable for us.

Cheers,
Martin

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Re: Irrigation: ditches, canals and drains

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On May 30, 2019, at 11:53 PM, Martin Koppenhoefer <[hidden email]> wrote:

Am Do., 30. Mai 2019 um 16:03 Uhr schrieb Mateusz Konieczny <[hidden email]>:
30 May 2019, 15:00 by [hidden email]:
Why does aqueduct have to be above ground level?
Maybe because one of main meanings of this word is
"bridge to convey water over an obstacle, such as a ravine or valley"?


the meaning of the term "aqueduct" is "leading water". Usually bridges are only constructed where they are needed,

yep.

I think this is truly a matter of what you are familiar with first. 

Growing up in California, the only usage of the word aqueduct I ever heard referred to the Califorina aquaduct from San Francisco to Los Angeles, and it is a giant trench dug in the ground and (now) lined with concrete. it obviously has other features (pumps and pipes to go over the mountains), but the iconic images of it everyone thinks of is the water in the trench next to interstate. 5. califorina has 3 major aqueduct systems, all to move water to Southern California. 

I learned about all the roman aqueducts and so forth much much later on TV, and they always showed the bridges and the tunnels to make some fountain work in Rome. 


here, the USGS shows a section of the Califorina aqueduct and a picture of an old Roman aqueduct (bridge), showing how some people equate any structure for conveying a supply of water from one area to another for the purpose of using / drinking the water as “an aqueduct” 

This is teaching materials for classrooms. 

the aqueducts I map in Japan usually have long at-grade open-air sections, pipe or open-top bridges, and lots of tunnels - similar to a "roman aqueduct” as I understand them. 


Javbw

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Re: Irrigation: ditches, canals and drains

Joseph Eisenberg
The usage of the word "aqueduct" in American English is broader than
the meaning of the word in British English.

Cambridge dictionaries defines the noun as "a structure for carrying
water across land, especially one like a high bridge with many arches
that carries pipes or a canal across a valley" -
https://dictionary.cambridge.org/dictionary/english/aqueduct

Oxford dictionaries: Noun "1. An artificial channel for conveying
water, typically in the form of a bridge across a valley or other
gap."
"2. A small duct in the body containing fluid."

But in the USA the word is alway used for long canals and tunnels
designed to carry water to a city or for irrigation:
Merriam-Webster (one of the better-researched American English dictionaries):
1 a: a conduit for water
especially : one for carrying a large quantity of flowing water
b : a structure for conveying a canal over a river or hollow
2 : a canal or passage in a part or organ
https://www.merriam-webster.com/dictionary/aqueduct

So in US and British English it's possible to use "aqueduct" to
describe a bridge that carries a canal or other artificial waterway
over a river or road. This is already a tag: bridge=aqueduct.

In this case "aque-duct" is similar to "via-duct", but carrying water
rather than a road:
Merriam-Webster: "a long elevated roadway usually consisting of a
series of short spans supported on arches, piers, or columns"
Cambridge: "a long, high bridge, usually held up by many arches, that
carries a railway or a road over a valley:"
Oxford: "A long bridge-like structure, typically a series of arches,
carrying a road or railway across a valley or other low ground."

Is there a better word than "aqueduct" that could be used to tag an
artificial waterway that transports useful water from one place to
another for irrigation, drinking water, or industrial usage, but is
not constructed like a canal or pipeline?

I still feel uncomfortable using the word "canal" for small waterways:
the basic meaning of the word "canal" seems to imply a navigable
waterway, just as a "river" is wide enough for a small boat, in
contrast with a stream, but perhaps this is specific to my dialect?

Can anyone show an example of an English waterway that is called a
"canal" locally but is less than 2 meters wide, or 1 meter wide?

On 5/31/19, John Willis via Tagging <[hidden email]> wrote:

>
>> On May 30, 2019, at 11:53 PM, Martin Koppenhoefer <[hidden email]>
>> wrote:
>>
>> Am Do., 30. Mai 2019 um 16:03 Uhr schrieb Mateusz Konieczny
>> <[hidden email] <mailto:[hidden email]>>:
>> 30 May 2019, 15:00 by [hidden email]
>> <mailto:[hidden email]>:
>> Why does aqueduct have to be above ground level?
>> Maybe because one of main meanings of this word is
>> "bridge to convey water over an obstacle, such as a ravine or valley"?
>>
>>
>> the meaning of the term "aqueduct" is "leading water". Usually bridges are
>> only constructed where they are needed,
>
> yep.
>
> I think this is truly a matter of what you are familiar with first.
>
> Growing up in California, the only usage of the word aqueduct I ever heard
> referred to the Califorina aquaduct from San Francisco to Los Angeles, and
> it is a giant trench dug in the ground and (now) lined with concrete. it
> obviously has other features (pumps and pipes to go over the mountains), but
> the iconic images of it everyone thinks of is the water in the trench next
> to interstate. 5. califorina has 3 major aqueduct systems, all to move water
> to Southern California.
>
> I learned about all the roman aqueducts and so forth much much later on TV,
> and they always showed the bridges and the tunnels to make some fountain
> work in Rome.
>
> https://www.usgs.gov/special-topic/water-science-school/science/aqueducts-move-water-past-and-today?qt-science_center_objects=0#qt-science_center_objects
> <https://www.usgs.gov/special-topic/water-science-school/science/aqueducts-move-water-past-and-today?qt-science_center_objects=0#qt-science_center_objects>
>
> here, the USGS shows a section of the Califorina aqueduct and a picture of
> an old Roman aqueduct (bridge), showing how some people equate any structure
> for conveying a supply of water from one area to another for the purpose of
> using / drinking the water as “an aqueduct”
>
> This is teaching materials for classrooms.
>
> the aqueducts I map in Japan usually have long at-grade open-air sections,
> pipe or open-top bridges, and lots of tunnels - similar to a "roman
> aqueduct” as I understand them.
>
>
> Javbw

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Re: Irrigation: ditches, canals and drains

Kevin Kenny-3
On Thu, May 30, 2019 at 8:08 PM Joseph Eisenberg
<[hidden email]> wrote:
> The usage of the word "aqueduct" in American English is broader than
> the meaning of the word in British English.

Perhaps, but note that the Roman aqueducts were long projects of
tunnels, covered ditches, and inverted syphons as well as bridges.
Would British English not call the Aqua Anio Vetus, Aqua Anio Novus,
Aqua Claudia or Aqua Marcia 'aqueducts'?  They are in keeping with the
Cambridge definition:

> Cambridge dictionaries defines the noun as "a structure for carrying
> water across land, especially one like a high bridge with many arches
> that carries pipes or a canal across a valley" -
> https://dictionary.cambridge.org/dictionary/english/aqueduct

except for the 'especially' clause, which describes an indicative
condition, not a necessary one.

> But in the USA the word is always used for long canals and tunnels
> designed to carry water to a city or for irrigation:
> Merriam-Webster (one of the better-researched American English dictionaries):
> 1 a: a conduit for water
> especially : one for carrying a large quantity of flowing water
> b : a structure for conveying a canal over a river or hollow

That's not true.  The Rexford Aqueduct existed to carry the Erie Canal
across the Mohawk River for transportation, not to move water, but to
move boats; likewise, the Roebling Aqueduct carried canal boats on the
Delaware & Hudson Canal across the Delaware River. The New York City
aqueduct system uses not only long tunnels, but also exploits natural
watercourses: a good part of its Schoharie Aqueduct is, for instance,
an artificial raising of the water flow in the Esopus Creek - the long
tunnel from the Schoharie Reservoir discharges into the Shandaken
Outlet, and the natural course of the Esopus carries it to the Ashokan
Reservoir.

The only necessary condition is: a conduit for water - although
ordinarily the quantity will be large.

> Is there a better word than "aqueduct" that could be used to tag an
> artificial waterway that transports useful water from one place to
> another for irrigation, drinking water, or industrial usage, but is
> not constructed like a canal or pipeline?

> I still feel uncomfortable using the word "canal" for small waterways:
> the basic meaning of the word "canal" seems to imply a navigable
> waterway, just as a "river" is wide enough for a small boat, in
> contrast with a stream, but perhaps this is specific to my dialect?

Some of the Salt River Project canals in Arizona, which are built to
carry irrigation water, are quite tiny indeed - surely not navigable.

Where I am, the use of "river" versus other names varies all over the
place. The Bronx River is a shallow and sluggish creek
https://en.wikipedia.org/wiki/Bronx_River#/media/File:Bronx_River_Bronxville_jeh.JPG.
The Schoharie Creek is a substantial river
https://s3.amazonaws.com/gs-waymarking-images/519eeb34-6bfa-4ca7-92a4-2cc9a4f7e862.jpeg.

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Re: Irrigation: ditches, canals and drains

dieterdreist
In reply to this post by Joseph Eisenberg


sent from a phone

> On 31. May 2019, at 02:06, Joseph Eisenberg <[hidden email]> wrote:
>
> So in US and British English it's possible to use "aqueduct" to
> describe a bridge that carries a canal or other artificial waterway
> over a river or road. This is already a tag: bridge=aqueduct.


yes, it is a property for a waterway. A waterway class is still required, agreed? Typically this would be canal I think.

Cheers, Martin
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