|Used on these elements|
|Status: in use|
|Tools for this tag|
This tag is used on an area or way, that is prone to flooding. This is mostly applicable to roads that go under water after heavy rains. Flooded roadways are often very dangerous to cross and many people die each year as a result.
Mapping Waterway Crossings
Mapping Flood Prone Bridges
For a flood prone bridge, you should ensure a bridge=* tag is on the relevant highway and add flood_prone=yes. Nothing really needs to be done to the waterway since the bridge is a structure above the waterway.
Mapping Flood Prone Highways
Photos were taken south of Barellan, in the Mirrool Creek floodplain.
The above photos are of the Gwydir highway east of Moree
While it is preferable to tag the entire way that is likely to go under water, if this information isn't known you can tag a node as flood_prone=yes as this may help routing software to avoid potentially hazardous crossings if there has been heavy rain.
Flood prone areas don't have water across them 99.9% of the time, so there isn't any perceived benefit in rendering these areas most of the time.
Emergency services may find it useful to have their own flood mapping that highlights these and similar tags, but this is a special use case.
Similar Tag Ideas
- It might be useful to tag the markers that indicate depth of water when flooded, although similar markers can be found along river banks and tidal water areas
- It might be useful to tag how often flooding gets or covers a certain area, eg once in 100 years.
- ford=* unlike flood prone areas, fords may be safe to cross if there is water across the roadway.
- Proposed features/floodplain
- "Landsat TM image analysis for identifying areas prone to flooding". In Spanish. Last updated 18 July 2011; accessed 31 July 2011.