There is a problem with the drain classification. It is useful to distinguish between a natural river and artificial drainage channel but mapnik assumes that a drain is narrow which is wrong. For example the South Forty Foot Drain in the Fens is, surprise, surprise, 40' wide. I am about to change the Cut Off Drain near Mildenhall to river as it will then be rendered at an appropriate width. Malcolm Boura 21:39, 5 June 2008 (UTC)
- A lot of drains - including many in the Fens *are* very narrow - possibly even narrow enough to jump over. The large drains - the Forty Foot Drain, the Hundred Foot Washes etc. - are more like canals than most drains. I think the waterway=drain tag is probably designed for drainage ditches - e.g. see here, rather than something like this. Richard B 23:49, 5 June 2008 (UTC)
- This is essentially a rendering bug. The renderer should use the width=* property of each feature to determine how many pixels to use at each zoom level. (If the width is not stated explicitly, then the renderer should use the default width for the type of feature; the default widths should be documented). --T99 22:57, 1 September 2012 (BST)
drain vs. ditch
How do I decide between the two? The pictures and descriptions look very similar.
- In my usage, drains are typically lined with concrete or rocks, while ditches are dug in bare ground. Drains also have a marked direction of flow and can be quite steep (I tag dam spillways as drains); ditches could be level. --T99 22:57, 1 September 2012 (BST)
How should one tag a drain hole where storm water flows from a street surface into an underground drain but the route of the drain cannot be determined? --T99 22:57, 1 September 2012 (BST)
- manhole=drain fits. Add hole:diameter=2 or similar if it's something huge. Alv 11:41, 3 September 2012 (BST)
As I see this page included in Category:Way Direction Dependent category, should I assume that the way must be draw so that the direction of the way is downstream?. If so is it better to add, as in page Tag:waterway=stream, the following sentence?
Direction of the way should be downstream.