Covered reservoirs

[DaveF63]

Hi Covered reservoirs (covered=yes) mapped as areas are being rendered solid blue, the same as open ones. Could it be amended to just a dashed outline or maybe narrow band of blue shading similar to the new national parks boundaries render?

[matthijsmelissen]

Do you have an example?

[DaveF63]

Sure: Specific: http://www.openstreetmap.org/#map=18/51.39740/-2.38307 That area also includes an example of what I mean by national park boundary rendering

Overpass: http://overpass-turbo.eu/s/6Br

[Rovastar]

For reference Math we have covered in the current db.

[matthijsmelissen]

Thanks for the example!

[gravitystorm]

maybe narrow band of blue shading similar to the new national parks boundaries

We should use this approach sparingly, and for sort of "collections" of things, or where we expect significant other amounts of point/line/polygons to appear inside (national parks, marinas, theme parks, tourism areas). This approach doesn't apply to reservoirs.

I don't have any comments on the actual topic at hand.

[althio]

You could render:

• what is on surface: building=yes, surface=grass, landuse=* ... (not the covered reservoir)
• AND/OR the covered reservoir as a regular reservoir with additional covered/underground effect (opacity and so on)

[matkoniecz]

Maybe style of waterways in tunnels may be adapted also for areas?

[mrwojo]

Whatever style is chosen shouldn't be too obtrusive in case interesting features are above.

Example: http://www.openstreetmap.org/way/218975789

Also note the tagging on that instance is man_made=reservoir_covered (TagInfo ~10k).

[mboeringa]

Just for reference, here is how I currently render covered reservoirs. Left OSM Standard, right my OSM Renderer for ArcGIS:

[matkoniecz]

With this rendering I would think that it is some sort of vegetation (it seems green and style is very similar to one used on Orienteering maps for undergrowth that is able to slow down movement).

[mboeringa]

With this rendering I would think that it is some sort of vegetation (it seems green and style is very similar to one used on Orienteering maps for undergrowth that is able to slow down movement).

I just showed it for reference. I don't use hatch symbols for vegetation in my personal style, so I don't think it will cause confusion. In addition, comparing symbols with other styles is not the most useful... Of course, any symbol can be a "look-alike" of any other symbol with a completely different meaning in another style.

That's why cartographers invented the concept of a "map legend"... ;)

The slight green tinge is caused by the blueish hatching, and light sandy background color of the reservoir symbol. In practice, I also label these covered reservoirs using their name, thus explaining what they are. However, I set a minimum area size for that labeling, so unfortunately, at this particular 1:25k scale in this example, they don't yet get labeled. At larger scales, they will.

[mboeringa]

Here's how that labeling and symbolization works out for a really huge covered reservoir in an urban environment like Paris:

On OSM, it's here: http://www.openstreetmap.org/node/2789983153#map=16/48.8243/2.3354

[matkoniecz]

I admit that I am not sure what is represented by [covered = yes landuse=reservoir].

Can somebody link to an example photos?

@DaveF63 Is https://commons.wikimedia.org/wiki/File:Covered_reservoir_seen_from_the_top_of_Primrose_Hill_-_geograph.org.uk_-_784303.jpg a photo of https://www.openstreetmap.org/way/43160349#map=18/51.39740/-2.38280 ?

[DaveF63]

I don't have photos, but generally it's any reservoir where the water isn't visible. In my area of the UK there are numerous water tanks, semi buried below ground level. The half above ground is landscaped, covered in earth & grass.

[Tomasz-W]

retaled to #2620

[jragusa]

I investigated these covered reservoirs and it seems there is a tagging mistake. Both examples proposed above (https://www.openstreetmap.org/way/43160349 and https://www.openstreetmap.org/node/2789983153) should be better described as man_made=reservoir_covered and it's the same for several equivalent "covered reservoirs".

A correct covered reservoir is for example https://www.openstreetmap.org/way/574995790 (see the aerial photograph) : a reservoir covered with a tarpaulin. Following this example, the rendering should not be changed.

So I propose to close this issue and recommend people to fix tag to man_made=reservoir_covered if they are semi-buried and covered by grass or add building=* if they are located in a building.

[Tomasz-W]

@kocio-pl https://github.com/gravitystorm/openstreetmap-carto/issues/1167#issuecomment-441454335

[kocio-pl]

The other tagging sounds sane, however we still don't know if/how to render them (see #2620):

https://wiki.openstreetmap.org/wiki/Tag%3Aman_made%3Dreservoir_covered