Hydrography Data

This provides a polygon coastline and islands layer which is based on the Topo50 products. It is a combination of the following layers:

• NZ Coastlines (Topo 1:50k)
• NZ Island Polygons (Topo 1:50k)
• NZ Auckland Is Island Polygons (Topo, 1:50k)
• NZ Campbell Is / Motu Ihupuku Island Polygons (Topo, 1:50k)
• NZ Antipodes Is Island Polygons (Topo, 1:25k)
• NZ Kermadec Is Island Polygons (Topo, 1:25k)
• NZ Bounty Is Island Polygons (Topo, 1:25k)
• NZ Snares Is / Tini Heke Island Polygons (Topo, 1:25k)
• NZ Chatham Is island polygons (Topo, 1:50k)

This topographic coastline is the line forming the boundary between the land and sea, defined by mean high water.

Islands from the NZ Island Polygons layer that lie within the NZ Coastline and Chatham Islands areas (i.e. islands in lakes, rivers and estuaries) have been removed.

The GIS workflow to create the layer is:

1. NZ Coastlines were converted from a polyline to a polygon using a polyline to polygon tool.
2. The resulting coastal polygon was then used as an input into an erase tool and run against the NZ Island Polygon layer to remove all islands lying within the NZ Mainland and Stewart Island.
3. This was then merged with the NZ Chatham Is island polygons (Topo, 1:50k) that have had the islands within the main island polygon removed, NZ Auckland Is Island Polygons (Topo, 1:50k), NZ Campbell Is / Motu Ihupuku Island, NZ Antipodes Is Island Polygons (Topo, 1:25k), NZ Kermadec Is Island Polygons (Topo, 1:25k), NZ Bounty Is Island Polygons (Topo, 1:25k) and NZ Snares Is / Tini Heke Island Polygons (Topo, 1:25k) layers using a merge tool.
4. Lake Onoke from the NZ Lake Polygons (Topo 1:50k) layer and Te Whanga Lagoon from the NZ Chatham Is lagoon polygons (Topo, 1:50k) layer were then erased from the resultant polygon layer to include these two water bodies in the coastline definition.

For more detailed description of each layer refer to the layer urls above.

A submarine object over which the water is shallow, which is detached from the shore and whose bottom is visible at low water; may be a menace to navigation on the surface

Data Dictionary for shoal_poly: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

A channel which carries surface water.

Data Dictionary for drain_cl: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

A natural, flowing body of water emptying into an ocean, lake or other body of water and usually fed along it's course by converging tributaries.

Data Dictionary for river_cl: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

River Names: For river names attributed to geometry features, please see NZ River Name Lines (Pilot) and NZ River Name Polygons (Pilot)

The line forming the boundary between the land and sea, defined by mean high water.

Data Dictionary for coastline: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

An artificial open waterway used for transportation, waterpower or irrigation.

Data Dictionary for canal_poly: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

An artificial open waterway used for transportation, waterpower or irrigation.

Data Dictionary for canal_cl: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

Coastal rocks; rocks between high and low tide

Data Dictionary for rock_poly: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

An isolated rock or rock formation between high and low tides.

Data Dictionary for rock_pnt: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

A natural, flowing body of water emptying into an ocean, lake or other body of water and usually fed along it's course by converging tributaries.

Data Dictionary for river_poly: apps.linz.govt.nz/topo-data-dictionary/index.aspx?...

This layer is a component of the Topo50 map series. The Topo50 map series provides topographic mapping for the New Zealand mainland, Chatham and New Zealand's offshore islands, at 1:50,000 scale.

Further information on Topo50:
www.linz.govt.nz/topography/topo-maps/topo50

River Names: For river names attributed to geometry features, please see NZ River Name Lines (Pilot) and NZ River Name Polygons (Pilot)