It looks like our long discussion a while back didn't lead to substantial changed to the wiki pages for waterway=drain, waterway=ditch and waterway=canal.
I was checking on how many waterway=ditch were tagged as being used for irrigation, and decided to slightly updated the pages. I've marked all features as "De facto", and slightly adjusted the descriptions and pages to suggest that: - A waterway=drain is lined by concrete or similar materials and is used to remove superfluous water - A waterway=ditch is not lined and is usually used for drainage, but can (controversially) be used for irrigation. I note that the page suggested irrigation=yes, but actually there are 4 options to showing that a ditch or canal is used for irrigation: 1) irrigation=yes was the first tag used, starting it 2011. As of May 2019, it has been used 200 times with canals and 2000 times with ditches. Most of these tags were added between 2011 and 2013. 2) service=irrigation was used starting in 2012, and as of May 2019 is used 12,000 times, mainly with canals but also with several hundred ditches 3) usage=irrigation was introduced in 2018 and usage is increasing quickly. It is currently used 6,000 times. 4) About 2000 hundred canals are tagged canal=irrigation and a few ditches are tagged ditch=irrigation or irrigation=ditch The tagging suggests that waterway=canal is more commonly used for irrigation features, but there certainly is significant usage of waterway=ditch for irrigation: overpass-turbo.eu finds 3605 ways tagged waterway=ditch plus one of the irrigation related tags: https://overpass-turbo.eu/s/JqW Comparisions: 10687 ways tagged waterway=canal and one of the irrigation tags: https://overpass-turbo.eu/s/JqX Waterway=drain is specified for irrigation on 1298 ways: https://overpass-turbo.eu/s/JqY So it looks like a number of mappers consider waterway=ditch appropriate for use with irrigation features, and there is even some use of waterway=drain for irrigation, which surprises me. What, then, should be the distinguishing characteristic between waterway=canal and waterway=ditch or =drain? Width or importance or navigability, or should we still mention the usage as the main difference? - Joseph E _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
