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Hydrants (Karlsruhe)

Fire hydrants from OpenStreetMap, classified by their potential to host a pop-up drinking fountain.

Layer id: karlsruhe-hydrants · Geometry: point · Features: 2,507 · Region: Karlsruhe · Project: Karlsruhe · OSM data as of: 2026-11-01T18:11:04Z · Exported: 2026-11-01T18:12:30+00:00 · Defined in: layers/karlsruhe.py

Parameters

Parameter Value Description
walking_distance_m 300 m A public drinking-water point within this distance (straight line) covers a hydrant.

Attributes

Attribute Type Label Source Tagged
osm_id string OSM object OSM element id
type string Type OSM tag fire_hydrant:type, default unknown 100 %
position string Position OSM tag fire_hydrant:position, default unknown 98 %
diameter (optional) string Pipe diameter (DN) OSM tag fire_hydrant:diameter 91 %
water_source string Water source OSM tag water_source, default unknown 6 %
excluded_by string Excluded by ids of matching rules in exclusion
dist_public_water_m (optional) integer (m) Nearest public drinking water (straight line) distance to nearest feature of Drinking water (Karlsruhe) where public is True (straight line)
status string Potential status classification: excluded if Excluded by is not empty; candidate_covered if Nearest public drinking water (straight line) ≤ 300; otherwise candidate_gap
pedestrian_potential (optional) number Pedestrian potential (0–100) potential of the Pedestrian potential (Karlsruhe, 100 m grid) cell the feature lies in
pedestrian_class (optional) string Pedestrian potential potential_class of the Pedestrian potential (Karlsruhe, 100 m grid) cell the feature lies in
  • Type (type):
    • pillar: Above ground (pillar) (171)
    • underground: Underground (2,319)
    • wall: Wall (1)
    • pipe: Suction pipe (7)
    • pond: Pond hydrant
    • unknown: Not tagged (8)
  • Position (position):
    • sidewalk: Sidewalk (1,168)
    • lane: Carriageway (999)
    • green: Green area (213)
    • parking_lot: Parking (63)
    • street: Street
    • unknown: Not tagged (61)
  • Water source (water_source):
    • main: Public water main (138)
    • pond: Pond (1)
    • stream: Stream
    • groundwater: Groundwater (1)
    • water_tank: Water tank
    • unknown: Not tagged (2,367)
  • Potential status (status) – closed list:
    • candidate_gap: Candidate – no public drinking water within 300 m – No exclusion rule applies and there is no public drinking-water point within 300 m (straight line). This is where a fountain could add the most. (1,203)
    • candidate_covered: Candidate – public drinking water within 300 m – No exclusion rule applies, but a public drinking-water point is already within 300 m (straight line). (308)
    • excluded: Excluded by a rule – At least one exclusion rule applies. (996)
  • Pedestrian potential (pedestrian_class):
    • very_high: Very high (60–100) – Among the busiest places for pedestrians in the region (modelled). (630)
    • high: High (40–60) (520)
    • medium: Medium (20–40) (794)
    • low: Low (5–20) (454)
    • minimal: Minimal (under 5) (67)

Exclusion rules for hydrants

A hydrant matching any of these rules gets the status "excluded".

Matching rule ids are stored in the attribute excluded_by.

Underground hydrant in the carriageway

An underground hydrant located in the road lane cannot host a fountain without blocking traffic and endangering users.

  • Applies if: Type is underground (Underground) and Position is lane (Carriageway)
  • Matches: 988 of 2,507
  • Source: Own assumption (road safety, Verkehrssicherungspflicht)
  • Status: Assumption
  • Rule id: underground_in_lane

Not fed from the drinking-water main

The hydrant draws from a pond, stream, tank or similar, not from the public drinking-water network, so it cannot supply drinking water.

  • Applies if: Water source is pond (Pond) or stream (Stream) or river or lake or groundwater (Groundwater) or water_tank (Water tank) or cistern or swimming_pool or sea
  • Matches: 2 of 2,507
  • Source: OSM tag water_source (main = public network)
  • Status: Assumption
  • Rule id: not_drinking_water_network

Suction pipe or pond hydrant

Dry suction pipes and pond hydrants are not pressurised network hydrants.

  • Applies if: Type is pipe (Suction pipe) or pond (Pond hydrant)
  • Matches: 7 of 2,507
  • Source: OSM wiki fire_hydrant:type
  • Status: Assumption
  • Rule id: suction_pipe

Assumptions

OpenStreetMap is the only data source

Hydrants and drinking-water points are taken from OSM only. Objects not mapped in OSM are missing from the analysis. Where few drinking-water points are mapped, the coverage gap is overstated.

Status: Assumption

Missing tags do not exclude

A rule only applies when the relevant OSM tag is present. Hydrants without type or position tags stay candidates.

Status: Assumption

Straight-line distance

Coverage uses the straight-line distance to the nearest public drinking-water point, not the walking distance. Rivers, railways and water bodies are ignored, so coverage is overestimated in places.

Status: Assumption

Network hydrants deliver drinking water

Every hydrant on the public network is treated as able to deliver drinking water. Water quality at the hydrant (standing water, dead-end mains) is not assessed yet (M3).

Status: Assumption

Not implemented yet

Step Item Description
M3 water quality Dead-end street Hydrant on a dead-end street; likely a dead-end main, so standing water is more likely.
M4 coverage Walking distance Replace the straight-line distance with the walking distance on the street network.
M5 scoring Weighted score Rank candidates by gap coverage (0.4), heat stress (0.3), population (0.2) and footfall (0.1).

Sources

Source Used for License
OpenStreetMap All features and their tags ODbL 1.0