[OSM-newbies] Small streams under minor tarmac roads

[Randy]

Nick Austin wrote:

>More people might use the tag if the wiki had some documentation for it.
>
>Nick.

I would definitely support a proposal on "culvert".

The "covered" property I have in RFC could be used on a waterway to 
designate this. But, a more specific and appropriate key of
"culvert" would, in my opinion be better.

That's one I have struggled with. In my area, I have a ~100 meter long 
covered drain, (originally a stream) that then has a brief opening before 
it extends under a motorway with frontage roads, and thence under a 
parking area and another street before surfacing again, near a lake. I've 
been forced to tag the two culverts as "tunnels" but "culvert" would be a 
much more appropriate term, in my opinion.

At another point, the drain passes under a four lane street. I've used 
bridge at that point, but actually the opening for the drain is narrower 
than in the first case. Again, culvert would be the better tag.

  I like the definition in Wikipedia:

"A culvert is a conduit used to enclose a flowing body of water. It may be 
used to allow water to pass underneath a road, railway, or embankment for 
example. Culverts can be made of many different materials; steel, 
polyvinyl chloride (PVC) and concrete are the most common. Formerly, 
construction of stone culverts was common."

I would assume that "flowing" can be either constant or intermittent in 
that definition, and would include extending a "dry wash", which only 
contains water during a rainstorm.

The other definitions I have seen are either too restrictive, or include 
"open" culverts ("drains", in OSMese).

My use described above would be, in part, for a ground level covering of 
the water, not one of the examples, but they are just examples.

I don't, however, much like the photo example in Wikipedia. That looks far 
too much like a railroad bridge, to me.

Note that the extended description in Wikipedia indicates that if it is 
over 20 feet wide in the US, for example four 5-foot concrete rectangular 
pipes laid side-by-side, then it is, by definition, a "bridge", so that it 
will receive proper periodic inspection. I can think of situations where 
OSM might want to break with that restriction, if for example the culvert 
did not pass under a way. My original example may, in part, fit this. I'll 
have to go measure it.

-- 
Randy