Key:ref:linz:hydrographic_id

The ref:linz:hydrographic_id=* tag is added to hydrographic data imported from LINZ. See LINZ for more information.

Just like street addresses in New Zealand, this tag is used to conflate data in OSM with data from LINZ. This is useful when LINZ updates its data to add new items, and when LINZ adds extra detail to existing data layers.

As a mapper, you can ignore this tag and freely edit/delete these features.

Multiple Values

You might encounter cases where there are multiple values for this tag. For example, ref:linz:hydrographic_id=123;124;125.

This is because a single node in OSM may contain multiple hydrographic features. For example, this node: 9234597422 9234597422 has 7 ID values because that node is a special purpose beacon, has a topmark, and has 5 sectored lights that each face in different directions.

Another cause of multiple ID values is if a large area or line crosses multiple nautical charts, and is merged into a single way in OSM. In this case, the source tag will show which charts that feature is from (e.g. source=LINZ;Auckland Harbour East Chart;Auckland Harbour West Chart

See also

• ref:linz:address_id=*
• ref:linz:building_id=*
• ref:linz:place_id=*
• ref:linz:topo50_id=*
• ref:linz:hydrographic_id=*
• ref:linz:pastoral_lease_id=*