Proposal:Whitewater

Whitewater
Proposal status:	Draft (under way)
Proposed by:	Babouche Verte
Draft started:	2022-09-26

Proposal

This proposal aims at clarifying and officialise some old proposals about whitewater sports grade, put in / egress, and description. Those proposals have all been abandoned but the scheme is widely used in OSM data (and rendered by app like Osmand).

The proposal is based on the tagging description on the whitewater sports page.

Tagging

The logic behind the tagging proposal is that a map will need a different approach as what we can find in a written guide (book, etc.). A book will typically propose sections with a minimum length, with a put-in and an egress for each section, so that the section has a coherency of level and an interest for an half-day (or more) outing. On a map we don't propose idea of outing but just indicate as precisely as possible the grade of the river, the danger, and any place suitable for getting in or out of the water.

What	How	Key and Value	Remarks
isolated rapid		whitewater:rapid_grade=#	cf. grade definition below
name of rapid		whitewater:rapid_name=*
description of the rapid		whitewater:description=*	Anything relevant to describ the rapid / hazard / playspot.
sections		whitewater:section_grade=#	cf. grade definition below If the section is mostly of a given grade, with few rapids of a superior grade, those rapids should be tagged as point with whitewater:rapid_grade if their exact localization is known. If their localization is only approximate, small sections of the grade of the most difficult rapid should be created around. It is not necessary to have a whitewater=put_in or whitewater=egress at the beginning or end of each section.
name of section		whitewater:section_name=*
description of the section		whitewater:description=*	Anything relevant to describ the section.
place usually used to get in or out of the water		whitewater=put_in;egress	Example: a beach in an eddy If the place allows to put in and out of the water, even if not interesting for one of the two usages (example, put_in just before a river mouth), it should be tagged as whitewater=put_in;egress Must be put at the left or right side of the river to know if it applies to left or right bank.
place usually used to get into the water, but from where it's not easy to get out of the water		whitewater=put_in	Example: drop put in
place usually used to get out of the water, not used to put into the water		whitewater=egress	Example: last eddy before an unrunnable
hole that generates a tow-back		whitewater:hazard=hole	Can be used with whitewater:rapid_grade=#A static wave will be tagged as a hole with the corresponding rapid_grade It has to be put at the beginning of the drop
sieve or strainer		whitewater:hazard=strainer	Any natural or man made feature that let water goes but that can block a craft or an human. It has to be put just before the danger. Also applicable to turns where the water can pile craft of people on underwater hole
static wave		whitewater:playspot=wave	A static wave interesting for surfing with at least one whitewater craft. It has to be tagged as a hazard as well

Grade: number between 0 and 6, according to the international scale, but with Arabic numbers ([0-6]) instead of Roman ones (I, II...) For grades from 1 to 4, it can be followed by "+" or "-". "+" means more difficult than usual but is obviously not of the superior grade (example: section with rapids of the given grade, but rhythm is intense). "-" means that it's actually of the given grade, but is easier than usual (Example: section with rapids of the given grade, but stop very easy between or inside rapids). For grade 5, one digit can be added to precise scale (example 5.0, 5.1 ...). "X" means unrunnable.

Do not use the notation like "2 (3)", instead tag whitewater:section_grade=2 and specify difficult rapid's location with whitewater:rapid_grade=3 (on a node).

As well do not use "2-3" or "2/3" or "2,3", but put the right section grade on the section where it applies, even if no put_in/egress is present.

The grade usually vary with the water flow. Put the grade the river has when the water flow correspond to what a typical whitewater kayaker would call "mid-water".

Description: As for name, should be in the local language, and use language suffixeif written in an other language.

Portage: a portage is tagged with a whitewater=egress, then a highway=path (or anything more suitable depending on the type of path), and an whitewater=put_in. Other attributes such as sac_scale=* can be used to indicate the difficulty of the portage.

waterway=weir and waterway=dam should be tagged with whitewater:rapid_grade=* (or whitewater:section_grade=*) to indicate if those constructions can be run or not by a whitewater craft.

Last eddy: last eddy before a whitewater:hazard=* has to be tagged with whitewater=egress.

Examples

An easy river with a unrunnable hole is tagged with whitewater:section_grade=1 until the last place where stop is usually possible. At the place of this stop, on the right side of the river, a whitewater=egress is put. The exact place of theunrunnable hole is tagged with whitewater:hazard=hole and whitewater:rapid_grade=X . After the hole whitewater:section_grade=1 is put again, and whitewater=put_in is put at the first place where going into the water with a whitewater craft is convenient. It's possible to get from the egress to the put_in, but it's an exhausting walk in the woods, so the path between both is tagged, highway=path with sac_scale=mountain_hiking.

A very small creek on a canyon that is runnable once every 5 years with lot of drops is tagged with whitewater:section_grade=5.

A very ugly and polluted river that has some small riffles and waves that nobody usually paddle but that could obviously be paddled or that have been paddled once is tagged with whitewater:section_grade=1.

A grade 2 river with a grade 3 rapid that is inside a short canyon of 200m length whose precise position is unknown and for which no portage is possible is tagged whitewater:section_grade=2 until the entrance of canyon, whitewater:section_grade=3 in the canyon and whitewater:section_grade=2 after the exit of the canyon.

Rendering

Grades can be rendered with a color, for example the same colors as the wikipedia page https://en.wikipedia.org/wiki/International_scale_of_river_difficulty but note that no color code is widely used and known in the whitewater world.

put_in and egress can be rendered with small icons representing water and one of two arrows.

hazards should be rendered so that it's visible and above all other layers. The two kind of hazards should have a different icon, since the kind of danger is different. Unrunnable hazards should have a different symbol than runnable hazards.

External discussions

External discussion is available on slack

Comments

Please comment on the discussion page.