Talk:Proposed features/sluice gate
Needed, but ...
this proposal takes a too narrow view. As you see in the Wikipedia, there is much more to cover with this feature - not only „in agricultural areas“, not only used for irrigation. --nkbre 00:12, 10 January 2011 (UTC)
I don't really think, that this change will do enaugh. The description has to be more general. For example:
A sluice gate is a facility to control water levels and flow rates of waterways. Sluice gates are commonly used for controlled irrigation and drainage of agricultural or other areas. They can be part of the flood protection system. In some cases, sluice gates are in pairs with one on either side of a dike. (see wikipedia:Sluice, wikipedia:de:)
--nkbre 18:03, 22 January 2011 (UTC)
Another type of gate which somehow needs to be covered by this proposal: a flood gate which is built into a dyke, often to make it possible to have a road going through a dyke.
--Eliasp 03:11, 28 May 2012 (BST)
Yes, there is a tag needed. But wikipedia:Coupure doesn't fit here. Because sluice_gate is a part of waterway and what you mean is a highway crossing a gate in a man_made=dyke. Water shouldn't flow here - never.
--sperlingskauz 23:44, 04 February 2017 (UTC)
There are seamark:gate:category=sluice with seamark:type=gate and seamark:gate:category=dyke with seamark:type=gate based on IHO Datamodel (International Hydrographic Organization). For further information see https://wiki.openstreetmap.org/wiki/Seamarks/Gates .
Adding info based on discussion between myself and another mapper, I'd go with: waterway = flow_control + flow_control = *,
where * can be: flap_valve (which - and that's what we discussed about - is not a manually adjustable way to control flows) orifice (just a discharge delimiter by using an opening smaller then peek flow - to back up water in upwards bassins) sluice_gate (which is something for which the opening height can be adjusted by choice - manually cranking it open or have it remote-controlled) vortex (a construction which makes the inflowing water 'whirl' through a cone, the energy loss allows for a more even discharge flow, less linearly tied to the water heigh differences on each side) mechanical (thinking variations like 'hydroslide' and such)
Surely there's probably more options, but it would allow to single out all nodes/constructions with water flow control elements through a simple query..
Personally I feel waterway=sluice would be better.
I think the tag layer *=flow_control adds needless complexity. Although I'm relatively new to the map, I feel that sometimes an engineering slant is put on things, such that the engineering design/purpose/classification of a structure becomes more important than the visible feature: the feature as it appears matters more to everyday map users, who don't need to know what purpose the structure serves. If we want to encourage as many contributors as possible, dual tag-layers may deter people from editing (or investing time reading documentation).
Besides, there are similar features that I'm not sure are always for flow_control: eg, here diluted effluent is discharged from the adjacent sewage facility. I'm no hydro engineer, but I assume this is standard operation, and not an overflow in time of overload (it was flowing when I was last there after a not particularly wet period). Would this need a different tag family than flow_control=*? But from the river-user's perspective, it's in the same family as 'man-made things with water flowing through'.
Otherwise I'd favour Key:seamark:type - although it's massively wordier, it is saying no more than 'you can see a [visible feature] here' - and this seems to me a better fit with OSM principles.
- EDIT: further browsing turns up a suggestion to move all these concrete-and-steel features of waterways out of the category waterway=* and into another. Worth considering imo. See Talk:Key:waterway #Debris_screens Eteb3 (talk)
What about floodgates?
In https://en.wikipedia.org/wiki/Floodgate we have that a floodgate "may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge system"
What exactly is the difference from a sluice gate and a floodgate?
Right now flow_control is slightly more used than floodgate (205 vs 167 objects)