Drain covers and blocked drains

I propose two extensions for tagging waterway=drain ways.

  1. Specific tags for how surface-visible drains are covered -

    • covered=metal_grating
    • covered=slabs
    • covered=no (open drains)
  2. blocked=yes or blocked_since=<ISO-8601 date> for blocked drains. In poorer areas of India (and presumably other countries), garbage may block drains for weeks, months, or even years. Sewage from such drains often pools into streets, resulting in increased cases of mosquito-borne diseases. This is certain to be valuable data for civic bodies.

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Can you attach a photo examples?


It could be useful to tag the nature of the blocked status. The drain could be blocked for many reasons - garbage, detritus, silt accumulation, encroachment. I don’t have a specific suggestion on how to tag it.

For those unfamiliar with what a blocked drain would look like, there’s this picture on Wikimedia Commons: Storm drain - Wikipedia

Based on contrapunctus’ proposed scheme, this particular drain would be a covered=no and blocked=yes. After the image was taken (and the drain cleaned), it would be covered=no and blocked=no.

The drain size and volume of garbage can vary a lot, so the distinction between blocked=yes and blocked=no can be up to interpretation. Also, in many cases the blocked=yes can be a very short-lived state of the drain, at which point it resembles mapping temporary features on the map.


How is the difference between a “covered” drain and a drain culvert defined?
A covered drain would therefore be waterway=drain + covered=slabs for example.
In comparision to a waterway=drain + tunnel=culvert.

How I imagine an open drain:

The North level Main Drain from Harold’s Bridge - geograph.org.uk - 1936076
The North level Main Drain from Harold’s Bridge by Richard Humphrey, CC BY-SA 2.0

How I imagine a culvert drain:

Culvert on New Ten Foot Drain - geograph.org.uk - 3405654
Culvert on New Ten Foot Drain by Richard Humphrey, CC BY-SA 2.0

Culvert in construction btw: File:Culvert and drains (9719055896).jpg - Wikimedia Commons

  1. Whether inlet= can be used on lines has been discussed. Talk:Key:inlet - OpenStreetMap Wiki
    2.1. There is already obstacle= . Almost all of the 7.7k blockage | Keys | OpenStreetMap Taginfo are used on waterway= .
    2.2. Weeks-long blockage is not worth adding. You should make a separate database / service / website to collect that ephemeral data, using OSM as the base data and basemap. That’s what the authorities should do. Even for months, in the long run, I would suggest looking into eg the 347 cleaning_schedule | Keys | OpenStreetMap Taginfo used for =toilets in Indore, to establish how frequently a water channel is cleaned regularly. Maybe service_times= could be adopted as a more general alternative.

It is referring to how narrower ones can have removable covers and gaps Channel and Trench Covers, Grid Covers | Vanstone is a Manufacturer of precast concrete products such as paving bricks in Pretoria, Gauteng, South Africa.

Sorry for the late response, I was traveling.


According to this proposal, the above should be waterway=drain + covered=slabs.

And this should be waterway=drain + covered=grating. (I know I said metal_grating originally, but if we’re leaving out the material, e.g. slabs rather than concrete_slabs, we should probably do the same here.)

Confusingly, very often in this area the drains were covered with gratings only for small sections, with the rest being underground and inaccessible (tunnel=*). So I’m not sure whether the following should be tagged as a node with man_made=manhole, as a node with covered=grating, or as a little way with waterway=drain + covered=grating. I guess the third one is the safest.

A section of covered drain short enough to possibly be considered a sewer hole.

Two more such sections, with a relatively linear covered=grating drain in the background.

@Vonter Thanks for the idea of tagging the actual location of the block. I guess the location of the block should be tagged as a node, if and when someone can figure it out.

I would say that the blocked=* key still makes sense on waterway=drain ways, in cases where the exact location of the blockage cannot be determined. I recall situations where I was unsure of the direction of a drain, because the drain was stagnant.

@mcliquid I understand that tunnel=* is used when the feature is completely underground, and would have to be dug up to be accessed. The covered=* wiki entry says

[Use this tag for:] […] Power lines, water mains, water drains, etc. in a narrow trench, with coverings traversable by traffic (foot, vehicle, or otherwise) and removable for access and maintenance.

So I’m really just proposing some new values for covered=*, which are in line with its current meaning.

@Kovoschiz Thanks for the suggestion to use blockage=*. Perhaps that can be documented.


I’ve got lots of images of dirty storm drains!

Here’s how they look inside:

To recap the proposed additions -

  1. covered=grating, covered=slabs, and covered=no for surface-visible waterway=drain ways.
  2. Documenting blockage=* for waterway=drain ways, with a caveat about temporary data.

If there are no objections, I’ll add them to the wiki in a few days.

Do civic bodies in India base policy and measures on Openstreetmap?

Here a few Italian variations, there are countless, bottom of sloped driveways, edges of pedestrian crossings, at entrance/exit of fuel stations (mainly to catch a water diluted hydrocarbon spill), just simple up slopey roads that have the tendency to develop into serious streams during rain so much so that manhole covers get blown off due to the water pressure. Many are service way wide as cover of a u shape lined open drain that runs along the sides of roads.

(wrong side of pedestrian crossing as the steepish slope is from west to east.

Not found the right tagging for these before but waterway=drain+covered=grating is getting in the right direction.

Right now typing drain in JOSM for a node actually pops up manhole with the tags man_made=manhole + manhole=rainwater, but that’s not what they are i.e. an access way to the actual drain system. When entering waterway=drain on a node JOSM complains this tag has to be on a way.

Do we tag these roadside gutters / drainage channels (not sure what the right word is) that were posted by @Vonter and @SekeRob with waterway=drain at all?

The Wiki page for drain shows a relatively wide waterway, like a stream. Same for @mcliquid’s examples.

The small channels that run along many streets look quite different to me.

See also Tagging of a steel gutter inlet where one suggestion was to use waterway=drainage_gutter for them.

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From that linked discussion, thanks, inlet=grate gets this Taginfo/wiki description of " grate


A horizontal grate that covers sumps, tunnels or culverts, on pavements or in a street to catch storm water.

Closer, no alerts in JOSM.