Allow stream to connect to a ditch

[cliffordsnow]

Right now a stream ends when connected to a ditch. I'd like to see the watershed area include ditches. BTW - I'm in an area next to the ocean that many of the small streams, often from mountains, connect to irrigation ditches before hitting the ocean.

[amandasaurus]

As a first step, I calculated how many loops in waterway=ditch there are. The OSM wiki says ditches should be mapped in direction of waterflow, but I've always suspected that wasn't often done.

There are 28,000 loops in just waterway=ditch alone. If you want to look at the data, the 35 MiB geopackage file can be downloaded from https://data.waterwaymap.org/2024-08-planet-waterway-ditch-loops.gpkg.

The existance of loops shouldn't mean that

The geojsons was created with this osm-lump-ways command:

osm-lump-ways-down -i planet.osm.pbf -f waterway=ditch --loops ditch-loops.geojsons

[cliffordsnow]

There is a small number in the area around here. One was mistagged as a waterway=ditch + water=pond. It should have been natural=water + water=pond. I'm going to investigate the ones in the farmland near me to see if I can figure out if they are loops or not.