Drain vs ditch

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Drain vs ditch

Eugene Podshivalov
Hi all,
Can anyone please explain the difference between waterway=ditch and drain?
As far as I understand the description on the English wiki they differ in usage:

drain - usually lined with concrete or similar and used to carry superfluous water like storm water or industrial discharge
ditch - used for irrigation

But the Russian wiki says that irrigation waterways should be tagged as drains.

So where is the truth?

Thanks,
Eugene

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Re: Drain vs ditch

Joseph Eisenberg
Ditches are also used to drain excess water.

In the USA we have irrigation ditches in dry areas and drainage ditches in wet areas.

Britain seems to lack irrigation - plenty of rain there.
On Fri, Jan 11, 2019 at 8:40 AM Eugene Podshivalov <[hidden email]> wrote:
Hi all,
Can anyone please explain the difference between waterway=ditch and drain?
As far as I understand the description on the English wiki they differ in usage:

drain - usually lined with concrete or similar and used to carry superfluous water like storm water or industrial discharge
ditch - used for irrigation

But the Russian wiki says that irrigation waterways should be tagged as drains.

So where is the truth?

Thanks,
Eugene
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Re: Drain vs ditch

sdoerr
In reply to this post by Eugene Podshivalov
On 10/01/2019 23:39, Eugene Podshivalov wrote:

> But the Russian wiki says that irrigation waterways should be tagged
> as drains.


OSM usage may be different, but to me as a native speaker a drain is by
definition about taking water away.


--

Steve


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Re: Drain vs ditch

John Willis
In reply to this post by Joseph Eisenberg




> On Jan 11, 2019, at 8:49 AM, Joseph Eisenberg <[hidden email]> wrote:
>
> Ditches are also used to drain excess water.
>
> In the USA we have irrigation ditches in dry areas and drainage ditches in wet areas.

it is especially difficult where I am, because the irrigation ditiches cascade from on set of fields to the next, sometimes are concrete, sometimes dirt; sometimes “natural”, sometimes man-made; they all flow like batter in a waffle iron.

“drains” that take away excess water and runoff eventually lead to another set of fields, before being dumped back in the river (only to begin the cycle again 500m later).

the idea of ditches and drains seem to be an attempt to define “channel” with a preset type, construction material, and usage - when it is very vague in some countries.  

Javbw
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Re: Drain vs ditch

Eugene Podshivalov
пт, 11 янв. 2019 г. в 02:50, Joseph Eisenberg <[hidden email]>:
Ditches are also used to drain excess water. 

In the USA we have irrigation ditches in dry areas and drainage ditches in wet areas.

Britain seems to lack irrigation - plenty of rain there.
If you use "ditch" for both land irrigation and drainage, what do you use the "drain" tag for then?

Eugene 

пт, 11 янв. 2019 г. в 03:00, John Willis <[hidden email]>:




> On Jan 11, 2019, at 8:49 AM, Joseph Eisenberg <[hidden email]> wrote:
>
> Ditches are also used to drain excess water.
>
> In the USA we have irrigation ditches in dry areas and drainage ditches in wet areas.

it is especially difficult where I am, because the irrigation ditiches cascade from on set of fields to the next, sometimes are concrete, sometimes dirt; sometimes “natural”, sometimes man-made; they all flow like batter in a waffle iron.

“drains” that take away excess water and runoff eventually lead to another set of fields, before being dumped back in the river (only to begin the cycle again 500m later).

the idea of ditches and drains seem to be an attempt to define “channel” with a preset type, construction material, and usage - when it is very vague in some countries. 

Javbw
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Re: Drain vs ditch

Graeme Fitzpatrick



On Fri, 11 Jan 2019 at 10:11, Eugene Podshivalov <[hidden email]> wrote:
If you use "ditch" for both land irrigation and drainage, what do you use the "drain" tag for then?

I've always worked on "drain" looking more artificial eg lined with concrete / rocks etc, while "ditch" is more-or-less only dirt, but I've never been really very happy with the distinction?

Thanks

Graeme
 

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Re: Drain vs ditch

Clifford Snow
In reply to this post by Joseph Eisenberg


On Thu, Jan 10, 2019 at 3:49 PM Joseph Eisenberg <[hidden email]> wrote:
Ditches are also used to drain excess water.

In the USA we have irrigation ditches in dry areas and drainage ditches in wet areas.

Joseph - I live in rainy western Washington. We have drainage ditches that are used for both. Drain the excess water off in the winter time and used for irrigation in the dry season.  Just to confuse the issue a little more.
--
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Re: Drain vs ditch

Marc Gemis
In reply to this post by Eugene Podshivalov
On Fri, Jan 11, 2019 at 12:40 AM Eugene Podshivalov <[hidden email]> wrote:
>
> Hi all,
> Can anyone please explain the difference between waterway=ditch and drain?
> As far as I understand the description on the English wiki they differ in usage:
> https://wiki.openstreetmap.org/wiki/Key:waterway
>
> drain - usually lined with concrete or similar and used to carry superfluous water like storm water or industrial discharge
> ditch - used for irrigation

The wiki page you link to defines a ditch as "An small artificial free
flow waterway used for carrying superfluous water along paths or roads
for drainage purposes."
I do not see the word "irrigation" in that definition. It corresponds
more to what Graeme wrote

"I've always worked on "drain" looking more artificial eg lined with
concrete / rocks etc, while "ditch" is more-or-less only dirt, but
I've never been really very happy with the distinction?"

I was always under the impression that the ones I encounter between
farmland and meadows, which typically are surrounded by dirt, ground,
plants are ditches. That drains are constructed with concrete or
similar material and that there are normally no plants on the bedding
of the drain.
Sometimes it's hard to tell the difference between ditch and stream,
because many streams were straightened along the borders of the
farmland.

m.

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Re: Drain vs ditch

John Willis


On Jan 11, 2019, at 3:00 PM, Marc Gemis <[hidden email]> wrote:

 was always under the impression that the ones I encounter between
farmland and meadows, which typically are surrounded by dirt, ground,
plants are ditches. That drains are constructed with concrete or
similar material and that there are normally no plants on the bedding
of the drain.

TL;DR - the connotation of “drain” is a problem. it is not “draining away” unwanted water, it is merely moving it around, and this connotation causes mapping issues. 

~~~~

I like this summary too. I think the issue is that “drain” has a connotation of moving water “away” from some spot where it is no longer needed or has been used - which is confusing for a lot of irrigation uses.

In places like southern California, which only have large (5x5m) open-air aqueduct systems to move usable water, and further distribution handled almost 100% by pipe for irrigation or drinking. sewer is also piped and handled by treatment plants, and “storm drains" merely channel the occasional rain to the ocean.

This makes mapping “drains” and "ditches” is super easy, because almost all drains/ditches are moving unwanted rainwater to a waterway/ocean.

but in my area of Japan, each neighborhood has several *Kilometers* of tiny concrete roadside “drains” (covered and uncovered) that have little doors or valves that farmers can open to flood ditches that flood rice fields. there are side channels, small storage ponds (3x3m), and other very detailed and intricate water management systems that make a Californian like me marvel at the rain management system they have created.  The drains act merely as storm drains the rest of the year, and integrate “streams” and other natural channels sometimes. but the rain they move is useful for irrigation; rain “drained” away from my area is actually irrigation water for people further downstream. 

the other issue is scale. some concrete drains are very tiny measure less than 20cm2, though most are 30cm2 or 50cm2 . most ditches are also roughly 30cm2. 

if we go by construction, and try to remove connotation of wastewater, then I think it is easy to map. 

 
Javbw

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Re: Drain vs ditch

Hufkratzer
https://wiki.openstreetmap.org/wiki/DE:Key:waterway says:
- drain is for rain or industrial water ("Abwassergraben") -> may be wastewater
- ditch is just for rain water ("Entwässerungsgraben") -> no wastewater

Am 11.1.2019 07:35, schrieb John Willis:


On Jan 11, 2019, at 3:00 PM, Marc Gemis <[hidden email]> wrote:

 was always under the impression that the ones I encounter between
farmland and meadows, which typically are surrounded by dirt, ground,
plants are ditches. That drains are constructed with concrete or
similar material and that there are normally no plants on the bedding
of the drain.

TL;DR - the connotation of “drain” is a problem. it is not “draining away” unwanted water, it is merely moving it around, and this connotation causes mapping issues. 

~~~~

I like this summary too. I think the issue is that “drain” has a connotation of moving water “away” from some spot where it is no longer needed or has been used - which is confusing for a lot of irrigation uses.

In places like southern California, which only have large (5x5m) open-air aqueduct systems to move usable water, and further distribution handled almost 100% by pipe for irrigation or drinking. sewer is also piped and handled by treatment plants, and “storm drains" merely channel the occasional rain to the ocean.

This makes mapping “drains” and "ditches” is super easy, because almost all drains/ditches are moving unwanted rainwater to a waterway/ocean.

but in my area of Japan, each neighborhood has several *Kilometers* of tiny concrete roadside “drains” (covered and uncovered) that have little doors or valves that farmers can open to flood ditches that flood rice fields. there are side channels, small storage ponds (3x3m), and other very detailed and intricate water management systems that make a Californian like me marvel at the rain management system they have created.  The drains act merely as storm drains the rest of the year, and integrate “streams” and other natural channels sometimes. but the rain they move is useful for irrigation; rain “drained” away from my area is actually irrigation water for people further downstream. 

the other issue is scale. some concrete drains are very tiny measure less than 20cm2, though most are 30cm2 or 50cm2 . most ditches are also roughly 30cm2. 

if we go by construction, and try to remove connotation of wastewater, then I think it is easy to map. 

 
Javbw


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Re: Drain vs ditch

Eugene Podshivalov
How about the following definitions?
drain - an artificial free flow waterway typically lined with concrete or similar used for carrying storm water or industrial discharge
ditch - an artificial free flow waterway used for draining or irrigating land

Eugene

пт, 11 янв. 2019 г. в 12:02, Hufkratzer <[hidden email]>:
https://wiki.openstreetmap.org/wiki/DE:Key:waterway says:
- drain is for rain or industrial water ("Abwassergraben") -> may be wastewater
- ditch is just for rain water ("Entwässerungsgraben") -> no wastewater

Am 11.1.2019 07:35, schrieb John Willis:


On Jan 11, 2019, at 3:00 PM, Marc Gemis <[hidden email]> wrote:

 was always under the impression that the ones I encounter between
farmland and meadows, which typically are surrounded by dirt, ground,
plants are ditches. That drains are constructed with concrete or
similar material and that there are normally no plants on the bedding
of the drain.

TL;DR - the connotation of “drain” is a problem. it is not “draining away” unwanted water, it is merely moving it around, and this connotation causes mapping issues. 

~~~~

I like this summary too. I think the issue is that “drain” has a connotation of moving water “away” from some spot where it is no longer needed or has been used - which is confusing for a lot of irrigation uses.

In places like southern California, which only have large (5x5m) open-air aqueduct systems to move usable water, and further distribution handled almost 100% by pipe for irrigation or drinking. sewer is also piped and handled by treatment plants, and “storm drains" merely channel the occasional rain to the ocean.

This makes mapping “drains” and "ditches” is super easy, because almost all drains/ditches are moving unwanted rainwater to a waterway/ocean.

but in my area of Japan, each neighborhood has several *Kilometers* of tiny concrete roadside “drains” (covered and uncovered) that have little doors or valves that farmers can open to flood ditches that flood rice fields. there are side channels, small storage ponds (3x3m), and other very detailed and intricate water management systems that make a Californian like me marvel at the rain management system they have created.  The drains act merely as storm drains the rest of the year, and integrate “streams” and other natural channels sometimes. but the rain they move is useful for irrigation; rain “drained” away from my area is actually irrigation water for people further downstream. 

the other issue is scale. some concrete drains are very tiny measure less than 20cm2, though most are 30cm2 or 50cm2 . most ditches are also roughly 30cm2. 

if we go by construction, and try to remove connotation of wastewater, then I think it is easy to map. 

 
Javbw


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Re: Drain vs ditch

Paul Allen
In reply to this post by Marc Gemis
On Fri, 11 Jan 2019 at 06:03, Marc Gemis <[hidden email]> wrote:

The wiki page you link to defines a ditch as "An small artificial free
flow waterway used for carrying superfluous water along paths or roads
for drainage purposes."
I do not see the word "irrigation" in that definition. It corresponds
more to what Graeme wrote

Depends on your perspective.

Yes, in rainy climes a drain moves water from a field that would otherwise be waterlogged
and the water goes into a stream or the sewer system.  But in dry climes a drain moves
water from a tank or other water supply and distribute it around a field.  Are you draining
the field or the tank?  Either way, it's a drain.

--
Paul


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Re: Drain vs ditch

Markus-5
In reply to this post by Eugene Podshivalov
Hi!

On Fri, 11 Jan 2019 at 00:40, Eugene Podshivalov <[hidden email]> wrote:

>
> Can anyone please explain the difference between waterway=ditch and drain?
> As far as I understand the description on the English wiki they differ in usage:
> https://wiki.openstreetmap.org/wiki/Key:waterway
>
> drain - usually lined with concrete or similar and used to carry superfluous water like storm water or industrial discharge
> ditch - used for irrigation
>
> But the Russian wiki says that irrigation waterways should be tagged as drains.
> https://wiki.openstreetmap.org/wiki/RU:Key:waterway

I can't find any information – neither on the English wiki nor on the
Russian translation – that either waterway=drain or waterway=ditch is
used for irrigation. They are both used to tag stretches of waters
carrying superfluous water, e.g. for drainage. As defined on the wiki,
the difference between ditch and drain is that waterway=drain is lined
with concrete or similar:

https://wiki.openstreetmap.org/wiki/Tag:waterway%3Ddrain

If you want to tag an artificial stretch of water used to carry useful
water for irrigation – as well as transportation and power generation
–, there is waterway=canal:

https://wiki.openstreetmap.org/wiki/Tag:waterway%3Dcanal

Regards

Markus

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Re: Drain vs ditch

Eugene Podshivalov
пт, 11 янв. 2019 г. в 18:30, Markus <[hidden email]>:
Hi!
I can't find any information – neither on the English wiki nor on the
Russian translation – that either waterway=drain or waterway=ditch is
used for irrigation.
 
Markus, you can find that in the "How to Map" section of the ditch proper page:
"If the ditch is used for irrigation, the usage of irrigation=yes is proposed."
i.e. irrigation ditche should be maps as waterway=ditch + irrigation=yes.

Eugene

пт, 11 янв. 2019 г. в 18:30, Markus <[hidden email]>:
Hi!

On Fri, 11 Jan 2019 at 00:40, Eugene Podshivalov <[hidden email]> wrote:
>
> Can anyone please explain the difference between waterway=ditch and drain?
> As far as I understand the description on the English wiki they differ in usage:
> https://wiki.openstreetmap.org/wiki/Key:waterway
>
> drain - usually lined with concrete or similar and used to carry superfluous water like storm water or industrial discharge
> ditch - used for irrigation
>
> But the Russian wiki says that irrigation waterways should be tagged as drains.
> https://wiki.openstreetmap.org/wiki/RU:Key:waterway

I can't find any information – neither on the English wiki nor on the
Russian translation – that either waterway=drain or waterway=ditch is
used for irrigation. They are both used to tag stretches of waters
carrying superfluous water, e.g. for drainage. As defined on the wiki,
the difference between ditch and drain is that waterway=drain is lined
with concrete or similar:

https://wiki.openstreetmap.org/wiki/Tag:waterway%3Ddrain

If you want to tag an artificial stretch of water used to carry useful
water for irrigation – as well as transportation and power generation
–, there is waterway=canal:

https://wiki.openstreetmap.org/wiki/Tag:waterway%3Dcanal

Regards

Markus

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Re: Drain vs ditch

Markus-5
On Fri, 11 Jan 2019 at 16:42, Eugene Podshivalov <[hidden email]> wrote:
>
> Markus, you can find that in the "How to Map" section of the ditch proper page:
> "If the ditch is used for irrigation, the usage of irrigation=yes is proposed."
> https://wiki.openstreetmap.org/wiki/Tag:waterway%3Dditch
> i.e. irrigation ditche should be maps as waterway=ditch + irrigation=yes.

Oh, please excuse me, I missed that.

It says 'proposed', so it isn't standard mapping practice. I also
couldn't find any discussion about that tag:

https://www.google.com/search?q=site%3Alists.openstreetmap.org+%22irrigation%3Dyes%22

Besides, the standard tag for waterway tagging is usage=*, e.g.
usage=irrigation:

https://wiki.openstreetmap.org/wiki/Key:usage#With_waterways

I propose to delete that proposal from the wiki as it contradicts the
definition of waterway=ditch.

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Re: Drain vs ditch

Hufkratzer
In reply to this post by Eugene Podshivalov
There is an abandoned proposal
https://wiki.openstreetmap.org/wiki/Proposed_features/Ditch
titled "Drainage/Irrigation Ditch"

and the German page
https://wiki.openstreetmap.org/wiki/DE:Tag:waterway=ditch
mentions "Bewässerungsgraben" which means irrigation ditch.

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Re: Drain vs ditch

Eugene Podshivalov
In reply to this post by Markus-5
I propose to delete that proposal from the wiki as it contradicts the
definition of waterway=ditch.  
I don't think we should delete it because "ditch" in reality does stand for both land drainage and irrigation.
In other words "ditches" are used to drain surplus water from wetland and supply water to dry land.
Whereas "drains" are used to drain storm or waste water or industrial discharge and are usually lined with concrete or similar.

I suggest we update the definitions on the wiki to reflect these statement clearly.  

пт, 11 янв. 2019 г. в 19:01, Markus <[hidden email]>:
On Fri, 11 Jan 2019 at 16:42, Eugene Podshivalov <[hidden email]> wrote:
>
> Markus, you can find that in the "How to Map" section of the ditch proper page:
> "If the ditch is used for irrigation, the usage of irrigation=yes is proposed."
> https://wiki.openstreetmap.org/wiki/Tag:waterway%3Dditch
> i.e. irrigation ditche should be maps as waterway=ditch + irrigation=yes.

Oh, please excuse me, I missed that.

It says 'proposed', so it isn't standard mapping practice. I also
couldn't find any discussion about that tag:

https://www.google.com/search?q=site%3Alists.openstreetmap.org+%22irrigation%3Dyes%22

Besides, the standard tag for waterway tagging is usage=*, e.g.
usage=irrigation:

https://wiki.openstreetmap.org/wiki/Key:usage#With_waterways

I propose to delete that proposal from the wiki as it contradicts the
definition of waterway=ditch.

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Re: Drain vs ditch

ael-3
In reply to this post by Markus-5
On Fri, Jan 11, 2019 at 04:29:05PM +0100, Markus wrote:

> Hi!
>
> On Fri, 11 Jan 2019 at 00:40, Eugene Podshivalov <[hidden email]> wrote:
> >
> > Can anyone please explain the difference between waterway=ditch and drain?
> > As far as I understand the description on the English wiki they differ in usage:
> > https://wiki.openstreetmap.org/wiki/Key:waterway
> >
> > drain - usually lined with concrete or similar and used to carry superfluous water like storm water or industrial discharge
> > ditch - used for irrigation
> >
> > But the Russian wiki says that irrigation waterways should be tagged as drains.
> > https://wiki.openstreetmap.org/wiki/RU:Key:waterway
>
> I can't find any information – neither on the English wiki nor on the
> Russian translation – that either waterway=drain or waterway=ditch is
> used for irrigation. They are both used to tag stretches of waters
> carrying superfluous water, e.g. for drainage. As defined on the wiki,
> the difference between ditch and drain is that waterway=drain is lined
> with concrete or similar:

As a native speaker, I do not recognise "canal" as appropriate for
irrigation. That is not to say that some canals may also be used
partly for irrigation.

But the phrase "irrigation ditch" is common and understood.  Bear in
mind that the UK is mainly a fairly wet place, so the need for
substantial irrigation is not high except in some special cases.  The
unqualified word "ditch" would normally be understood as an artificial
unlined and usually small watercourse. But also, in certain contexts,
for a historic trench acting as a defense or fence, not necessarily
containing water.

That seems to accord with a the sub tag irrigation=yes on ditches -
and maybe on other waterways if that is one of the uses/functions.

ael


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Re: Drain vs ditch

Markus-5
In reply to this post by Hufkratzer
On Fri, 11 Jan 2019 at 17:24, Hufkratzer <[hidden email]> wrote:
>
> and the German page
> https://wiki.openstreetmap.org/wiki/DE:Tag:waterway=ditch
> mentions "Bewässerungsgraben" which means irrigation ditch.

A wiki page in non-English language should be a translation. Defining
a tag differently is problematical as its meaning becomes diluted or
worst gets lost.

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Re: Drain vs ditch

Tod Fitch
In reply to this post by ael-3

> On Jan 11, 2019, at 8:36 AM, ael <[hidden email]> wrote:
>
> As a native speaker, I do not recognise "canal" as appropriate for
> irrigation. That is not to say that some canals may also be used
> partly for irrigation.
>
> But the phrase "irrigation ditch" is common and understood.  Bear in
> mind that the UK is mainly a fairly wet place, so the need for
> substantial irrigation is not high except in some special cases.  The
> unqualified word "ditch" would normally be understood as an artificial
> unlined and usually small watercourse. But also, in certain contexts,
> for a historic trench acting as a defense or fence, not necessarily
> containing water.
>
> That seems to accord with a the sub tag irrigation=yes on ditches -
> and maybe on other waterways if that is one of the uses/functions.
>
> ael
>
+1

In the desert where I was raised the cotton fields were surrounded with “irrigation ditches”, or “ditches” for short. The fields were watered from the ditches by either syphon hoses or sluice gates.

Later, when working on road projects, I found that the low areas on the sides of roads (often used as “side borrow” areas during construction of the roadway) were formally called “drainage ditches” or just “ditches” for short.

So to me a ditch is simply a channel dug to move water.

But I am an American and our terms diverge somewhat from UK usage. So I looked it up in my older paper version of the OED to find the first two definition are “1. An excavation narrow in proportion to its length; the trench or fosse of a fortification, etc.”. “2. Such a hollow dug out to receive or conduct water, esp. to carry off the surface drainage of a road or field, etc.”

Based on the second, I can see the reason why some would conflate “drainage ditch” with simply “ditch”. But I don’t see from this where even in UK usage a ditch has to be for drainage. It is simply a long narrow excavation and, in the waterway sense, dug to conduct water from one place to another.


Cheers!
tf



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